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Theaetetus by Plato

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the fiction of time between ourselves and realities? Why should we single
out one of these abstractions to be the a priori condition of all the
others? It comes last and not first in the order of our thoughts, and is
not the condition precedent of them, but the last generalization of them.
Nor can any principle be imagined more suicidal to philosophy than to
assume that all the truth which we are capable of attaining is seen only
through an unreal medium. If all that exists in time is illusion, we may
well ask with Plato, 'What becomes of the mind?'

Leaving the a priori conditions of sensation we may proceed to consider
acts of sense. These admit of various degrees of duration or intensity;
they admit also of a greater or less extension from one object, which is
perceived directly, to many which are perceived indirectly or in a less
degree, and to the various associations of the object which are latent in
the mind. In general the greater the intension the less the extension of
them. The simplest sensation implies some relation of objects to one
another, some position in space, some relation to a previous or subsequent
sensation. The acts of seeing and hearing may be almost unconscious and
may pass away unnoted; they may also leave an impression behind them or
power of recalling them. If, after seeing an object we shut our eyes, the
object remains dimly seen in the same or about the same place, but with
form and lineaments half filled up. This is the simplest act of memory.
And as we cannot see one thing without at the same time seeing another,
different objects hang together in recollection, and when we call for one
the other quickly follows. To think of the place in which we have last
seen a thing is often the best way of recalling it to the mind. Hence
memory is dependent on association. The act of recollection may be
compared to the sight of an object at a great distance which we have
previously seen near and seek to bring near to us in thought. Memory is to
sense as dreaming is to waking; and like dreaming has a wayward and
uncertain power of recalling impressions from the past.

Thus begins the passage from the outward to the inward sense. But as yet
there is no conception of a universal--the mind only remembers the
individual object or objects, and is always attaching to them some colour
or association of sense. The power of recollection seems to depend on the
intensity or largeness of the perception, or on the strength of some
emotion with which it is inseparably connected. This is the natural memory
which is allied to sense, such as children appear to have and barbarians
and animals. It is necessarily limited in range, and its limitation is its
strength. In later life, when the mind has become crowded with names,
acts, feelings, images innumerable, we acquire by education another memory
of system and arrangement which is both stronger and weaker than the first
--weaker in the recollection of sensible impressions as they are
represented to us by eye or ear--stronger by the natural connexion of ideas
with objects or with one another. And many of the notions which form a
part of the train of our thoughts are hardly realized by us at the time,
but, like numbers or algebraical symbols, are used as signs only, thus
lightening the labour of recollection.

And now we may suppose that numerous images present themselves to the mind,
which begins to act upon them and to arrange them in various ways. Besides
the impression of external objects present with us or just absent from us,
we have a dimmer conception of other objects which have disappeared from
our immediate recollection and yet continue to exist in us. The mind is
full of fancies which are passing to and fro before it. Some feeling or
association calls them up, and they are uttered by the lips. This is the
first rudimentary imagination, which may be truly described in the language
of Hobbes, as 'decaying sense,' an expression which may be applied with
equal truth to memory as well. For memory and imagination, though we
sometimes oppose them, are nearly allied; the difference between them seems
chiefly to lie in the activity of the one compared with the passivity of
the other. The sense decaying in memory receives a flash of light or life
from imagination. Dreaming is a link of connexion between them; for in
dreaming we feebly recollect and also feebly imagine at one and the same
time. When reason is asleep the lower part of the mind wanders at will
amid the images which have been received from without, the intelligent
element retires, and the sensual or sensuous takes its place. And so in
the first efforts of imagination reason is latent or set aside; and images,
in part disorderly, but also having a unity (however imperfect) of their
own, pour like a flood over the mind. And if we could penetrate into the
heads of animals we should probably find that their intelligence, or the
state of what in them is analogous to our intelligence, is of this nature.

Thus far we have been speaking of men, rather in the points in which they
resemble animals than in the points in which they differ from them. The
animal too has memory in various degrees, and the elements of imagination,
if, as appears to be the case, he dreams. How far their powers or
instincts are educated by the circumstances of their lives or by
intercourse with one another or with mankind, we cannot precisely tell.
They, like ourselves, have the physical inheritance of form, scent,
hearing, sight, and other qualities or instincts. But they have not the
mental inheritance of thoughts and ideas handed down by tradition, 'the
slow additions that build up the mind' of the human race. And language,
which is the great educator of mankind, is wanting in them; whereas in us
language is ever present--even in the infant the latent power of naming is
almost immediately observable. And therefore the description which has
been already given of the nascent power of the faculties is in reality an
anticipation. For simultaneous with their growth in man a growth of
language must be supposed. The child of two years old sees the fire once
and again, and the feeble observation of the same recurring object is
associated with the feeble utterance of the name by which he is taught to
call it. Soon he learns to utter the name when the object is no longer
there, but the desire or imagination of it is present to him. At first in
every use of the word there is a colour of sense, an indistinct picture of
the object which accompanies it. But in later years he sees in the name
only the universal or class word, and the more abstract the notion becomes,
the more vacant is the image which is presented to him. Henceforward all
the operations of his mind, including the perceptions of sense, are a
synthesis of sensations, words, conceptions. In seeing or hearing or
looking or listening the sensible impression prevails over the conception
and the word. In reflection the process is reversed--the outward object
fades away into nothingness, the name or the conception or both together
are everything. Language, like number, is intermediate between the two,
partaking of the definiteness of the outer and of the universality of the
inner world. For logic teaches us that every word is really a universal,
and only condescends by the help of position or circumlocution to become
the expression of individuals or particulars. And sometimes by using words
as symbols we are able to give a 'local habitation and a name' to the
infinite and inconceivable.

Thus we see that no line can be drawn between the powers of sense and of
reflection--they pass imperceptibly into one another. We may indeed
distinguish between the seeing and the closed eye--between the sensation
and the recollection of it. But this distinction carries us a very little
way, for recollection is present in sight as well as sight in recollection.
There is no impression of sense which does not simultaneously recall
differences of form, number, colour, and the like. Neither is such a
distinction applicable at all to our internal bodily sensations, which give
no sign of themselves when unaccompanied with pain, and even when we are
most conscious of them, have often no assignable place in the human frame.
Who can divide the nerves or great nervous centres from the mind which uses
them? Who can separate the pains and pleasures of the mind from the pains
and pleasures of the body? The words 'inward and outward,' 'active and
passive,' 'mind and body,' are best conceived by us as differences of
degree passing into differences of kind, and at one time and under one
aspect acting in harmony and then again opposed. They introduce a system
and order into the knowledge of our being; and yet, like many other general
terms, are often in advance of our actual analysis or observation.

According to some writers the inward sense is only the fading away or
imperfect realization of the outward. But this leaves out of sight one
half of the phenomenon. For the mind is not only withdrawn from the world
of sense but introduced to a higher world of thought and reflection, in
which, like the outward sense, she is trained and educated. By use the
outward sense becomes keener and more intense, especially when confined
within narrow limits. The savage with little or no thought has a quicker
discernment of the track than the civilised man; in like manner the dog,
having the help of scent as well as of sight, is superior to the savage.
By use again the inward thought becomes more defined and distinct; what was
at first an effort is made easy by the natural instrumentality of language,
and the mind learns to grasp universals with no more exertion than is
required for the sight of an outward object. There is a natural connexion
and arrangement of them, like the association of objects in a landscape.
Just as a note or two of music suffices to recall a whole piece to the
musician's or composer's mind, so a great principle or leading thought
suggests and arranges a world of particulars. The power of reflection is
not feebler than the faculty of sense, but of a higher and more
comprehensive nature. It not only receives the universals of sense, but
gives them a new content by comparing and combining them with one another.
It withdraws from the seen that it may dwell in the unseen. The sense only
presents us with a flat and impenetrable surface: the mind takes the world
to pieces and puts it together on a new pattern. The universals which are
detached from sense are reconstructed in science. They and not the mere
impressions of sense are the truth of the world in which we live; and (as
an argument to those who will only believe 'what they can hold in their
hands') we may further observe that they are the source of our power over
it. To say that the outward sense is stronger than the inward is like
saying that the arm of the workman is stronger than the constructing or
directing mind.

Returning to the senses we may briefly consider two questions--first their
relation to the mind, secondly, their relation to outward objects:--

1. The senses are not merely 'holes set in a wooden horse' (Theaet.), but
instruments of the mind with which they are organically connected. There
is no use of them without some use of words--some natural or latent logic--
some previous experience or observation. Sensation, like all other mental
processes, is complex and relative, though apparently simple. The senses
mutually confirm and support one another; it is hard to say how much our
impressions of hearing may be affected by those of sight, or how far our
impressions of sight may be corrected by the touch, especially in infancy.
The confirmation of them by one another cannot of course be given by any
one of them. Many intuitions which are inseparable from the act of sense
are really the result of complicated reasonings. The most cursory glance
at objects enables the experienced eye to judge approximately of their
relations and distance, although nothing is impressed upon the retina
except colour, including gradations of light and shade. From these
delicate and almost imperceptible differences we seem chiefly to derive our
ideas of distance and position. By comparison of what is near with what is
distant we learn that the tree, house, river, etc. which are a long way off
are objects of a like nature with those which are seen by us in our
immediate neighbourhood, although the actual impression made on the eye is
very different in one case and in the other. This is a language of 'large
and small letters' (Republic), slightly differing in form and exquisitely
graduated by distance, which we are learning all our life long, and which
we attain in various degrees according to our powers of sight or
observation. There is nor the consideration. The greater or less strain
upon the nerves of the eye or ear is communicated to the mind and silently
informs the judgment. We have also the use not of one eye only, but of
two, which give us a wider range, and help us to discern, by the greater or
less acuteness of the angle which the rays of sight form, the distance of
an object and its relation to other objects. But we are already passing
beyond the limits of our actual knowledge on a subject which has given rise
to many conjectures. More important than the addition of another
conjecture is the observation, whether in the case of sight or of any other
sense, of the great complexity of the causes and the great simplicity of
the effect.

The sympathy of the mind and the ear is no less striking than the sympathy
of the mind and the eye. Do we not seem to perceive instinctively and as
an act of sense the differences of articulate speech and of musical notes?
Yet how small a part of speech or of music is produced by the impression of
the ear compared with that which is furnished by the mind!

Again: the more refined faculty of sense, as in animals so also in man,
seems often to be transmitted by inheritance. Neither must we forget that
in the use of the senses, as in his whole nature, man is a social being,
who is always being educated by language, habit, and the teaching of other
men as well as by his own observation. He knows distance because he is
taught it by a more experienced judgment than his own; he distinguishes
sounds because he is told to remark them by a person of a more discerning
ear. And as we inherit from our parents or other ancestors peculiar powers
of sense or feeling, so we improve and strengthen them, not only by regular
teaching, but also by sympathy and communion with other persons.

2. The second question, namely, that concerning the relation of the mind
to external objects, is really a trifling one, though it has been made the
subject of a famous philosophy. We may if we like, with Berkeley, resolve
objects of sense into sensations; but the change is one of name only, and
nothing is gained and something is lost by such a resolution or confusion
of them. For we have not really made a single step towards idealism, and
any arbitrary inversion of our ordinary modes of speech is disturbing to
the mind. The youthful metaphysician is delighted at his marvellous
discovery that nothing is, and that what we see or feel is our sensation
only: for a day or two the world has a new interest to him; he alone knows
the secret which has been communicated to him by the philosopher, that mind
is all--when in fact he is going out of his mind in the first intoxication
of a great thought. But he soon finds that all things remain as they were
--the laws of motion, the properties of matter, the qualities of
substances. After having inflicted his theories on any one who is willing
to receive them 'first on his father and mother, secondly on some other
patient listener, thirdly on his dog,' he finds that he only differs from
the rest of mankind in the use of a word. He had once hoped that by
getting rid of the solidity of matter he might open a passage to worlds
beyond. He liked to think of the world as the representation of the divine
nature, and delighted to imagine angels and spirits wandering through
space, present in the room in which he is sitting without coming through
the door, nowhere and everywhere at the same instant. At length he finds
that he has been the victim of his own fancies; he has neither more nor
less evidence of the supernatural than he had before. He himself has
become unsettled, but the laws of the world remain fixed as at the
beginning. He has discovered that his appeal to the fallibility of sense
was really an illusion. For whatever uncertainty there may be in the
appearances of nature, arises only out of the imperfection or variation of
the human senses, or possibly from the deficiency of certain branches of
knowledge; when science is able to apply her tests, the uncertainty is at
an end. We are apt sometimes to think that moral and metaphysical
philosophy are lowered by the influence which is exercised over them by
physical science. But any interpretation of nature by physical science is
far in advance of such idealism. The philosophy of Berkeley, while giving
unbounded license to the imagination, is still grovelling on the level of

We may, if we please, carry this scepticism a step further, and deny, not
only objects of sense, but the continuity of our sensations themselves. We
may say with Protagoras and Hume that what is appears, and that what
appears appears only to individuals, and to the same individual only at one
instant. But then, as Plato asks,--and we must repeat the question,--What
becomes of the mind? Experience tells us by a thousand proofs that our
sensations of colour, taste, and the like, are the same as they were an
instant ago--that the act which we are performing one minute is continued
by us in the next--and also supplies abundant proof that the perceptions of
other men are, speaking generally, the same or nearly the same with our
own. After having slowly and laboriously in the course of ages gained a
conception of a whole and parts, of the constitution of the mind, of the
relation of man to God and nature, imperfect indeed, but the best we can,
we are asked to return again to the 'beggarly elements' of ancient
scepticism, and acknowledge only atoms and sensations devoid of life or
unity. Why should we not go a step further still and doubt the existence
of the senses of all things? We are but 'such stuff as dreams are made
of;' for we have left ourselves no instruments of thought by which we can
distinguish man from the animals, or conceive of the existence even of a
mollusc. And observe, this extreme scepticism has been allowed to spring
up among us, not, like the ancient scepticism, in an age when nature and
language really seemed to be full of illusions, but in the eighteenth and
nineteenth centuries, when men walk in the daylight of inductive science.

The attractiveness of such speculations arises out of their true nature not
being perceived. They are veiled in graceful language; they are not pushed
to extremes; they stop where the human mind is disposed also to stop--short
of a manifest absurdity. Their inconsistency is not observed by their
authors or by mankind in general, who are equally inconsistent themselves.
They leave on the mind a pleasing sense of wonder and novelty: in youth
they seem to have a natural affinity to one class of persons as poetry has
to another; but in later life either we drift back into common sense, or we
make them the starting-points of a higher philosophy.

We are often told that we should enquire into all things before we accept
them;--with what limitations is this true? For we cannot use our senses
without admitting that we have them, or think without presupposing that
there is in us a power of thought, or affirm that all knowledge is derived
from experience without implying that this first principle of knowledge is
prior to experience. The truth seems to be that we begin with the natural
use of the mind as of the body, and we seek to describe this as well as we
can. We eat before we know the nature of digestion; we think before we
know the nature of reflection. As our knowledge increases, our perception
of the mind enlarges also. We cannot indeed get beyond facts, but neither
can we draw any line which separates facts from ideas. And the mind is not
something separate from them but included in them, and they in the mind,
both having a distinctness and individuality of their own. To reduce our
conception of mind to a succession of feelings and sensations is like the
attempt to view a wide prospect by inches through a microscope, or to
calculate a period of chronology by minutes. The mind ceases to exist when
it loses its continuity, which though far from being its highest
determination, is yet necessary to any conception of it. Even an inanimate
nature cannot be adequately represented as an endless succession of states
or conditions.

Paragraph II. Another division of the subject has yet to be considered:
Why should the doctrine that knowledge is sensation, in ancient times, or
of sensationalism or materialism in modern times, be allied to the lower
rather than to the higher view of ethical philosophy? At first sight the
nature and origin of knowledge appear to be wholly disconnected from ethics
and religion, nor can we deny that the ancient Stoics were materialists, or
that the materialist doctrines prevalent in modern times have been
associated with great virtues, or that both religious and philosophical
idealism have not unfrequently parted company with practice. Still upon
the whole it must be admitted that the higher standard of duty has gone
hand in hand with the higher conception of knowledge. It is Protagoras who
is seeking to adapt himself to the opinions of the world; it is Plato who
rises above them: the one maintaining that all knowledge is sensation; the
other basing the virtues on the idea of good. The reason of this
phenomenon has now to be examined.

By those who rest knowledge immediately upon sense, that explanation of
human action is deemed to be the truest which is nearest to sense. As
knowledge is reduced to sensation, so virtue is reduced to feeling,
happiness or good to pleasure. The different virtues--the various
characters which exist in the world--are the disguises of self-interest.
Human nature is dried up; there is no place left for imagination, or in any
higher sense for religion. Ideals of a whole, or of a state, or of a law
of duty, or of a divine perfection, are out of place in an Epicurean
philosophy. The very terms in which they are expressed are suspected of
having no meaning. Man is to bring himself back as far as he is able to
the condition of a rational beast. He is to limit himself to the pursuit
of pleasure, but of this he is to make a far-sighted calculation;--he is to
be rationalized, secularized, animalized: or he is to be an amiable
sceptic, better than his own philosophy, and not falling below the opinions
of the world.

Imagination has been called that 'busy faculty' which is always intruding
upon us in the search after truth. But imagination is also that higher
power by which we rise above ourselves and the commonplaces of thought and
life. The philosophical imagination is another name for reason finding an
expression of herself in the outward world. To deprive life of ideals is
to deprive it of all higher and comprehensive aims and of the power of
imparting and communicating them to others. For men are taught, not by
those who are on a level with them, but by those who rise above them, who
see the distant hills, who soar into the empyrean. Like a bird in a cage,
the mind confined to sense is always being brought back from the higher to
the lower, from the wider to the narrower view of human knowledge. It
seeks to fly but cannot: instead of aspiring towards perfection, 'it
hovers about this lower world and the earthly nature.' It loses the
religious sense which more than any other seems to take a man out of
himself. Weary of asking 'What is truth?' it accepts the 'blind witness of
eyes and ears;' it draws around itself the curtain of the physical world
and is satisfied. The strength of a sensational philosophy lies in the
ready accommodation of it to the minds of men; many who have been
metaphysicians in their youth, as they advance in years are prone to
acquiesce in things as they are, or rather appear to be. They are
spectators, not thinkers, and the best philosophy is that which requires of
them the least amount of mental effort.

As a lower philosophy is easier to apprehend than a higher, so a lower way
of life is easier to follow; and therefore such a philosophy seems to
derive a support from the general practice of mankind. It appeals to
principles which they all know and recognize: it gives back to them in a
generalized form the results of their own experience. To the man of the
world they are the quintessence of his own reflections upon life. To
follow custom, to have no new ideas or opinions, not to be straining after
impossibilities, to enjoy to-day with just so much forethought as is
necessary to provide for the morrow, this is regarded by the greater part
of the world as the natural way of passing through existence. And many who
have lived thus have attained to a lower kind of happiness or equanimity.
They have possessed their souls in peace without ever allowing them to
wander into the region of religious or political controversy, and without
any care for the higher interests of man. But nearly all the good (as well
as some of the evil) which has ever been done in this world has been the
work of another spirit, the work of enthusiasts and idealists, of apostles
and martyrs. The leaders of mankind have not been of the gentle Epicurean
type; they have personified ideas; they have sometimes also been the
victims of them. But they have always been seeking after a truth or ideal
of which they fell short; and have died in a manner disappointed of their
hopes that they might lift the human race out of the slough in which they
found them. They have done little compared with their own visions and
aspirations; but they have done that little, only because they sought to
do, and once perhaps thought that they were doing, a great deal more.

The philosophies of Epicurus or Hume give no adequate or dignified
conception of the mind. There is no organic unity in a succession of
feeling or sensations; no comprehensiveness in an infinity of separate
actions. The individual never reflects upon himself as a whole; he can
hardly regard one act or part of his life as the cause or effect of any
other act or part. Whether in practice or speculation, he is to himself
only in successive instants. To such thinkers, whether in ancient or in
modern times, the mind is only the poor recipient of impressions--not the
heir of all the ages, or connected with all other minds. It begins again
with its own modicum of experience having only such vague conceptions of
the wisdom of the past as are inseparable from language and popular
opinion. It seeks to explain from the experience of the individual what
can only be learned from the history of the world. It has no conception of
obligation, duty, conscience--these are to the Epicurean or Utilitarian
philosopher only names which interfere with our natural perceptions of
pleasure and pain.

There seem then to be several answers to the question, Why the theory that
all knowledge is sensation is allied to the lower rather than to the higher
view of ethical philosophy:--1st, Because it is easier to understand and
practise; 2ndly, Because it is fatal to the pursuit of ideals, moral,
political, or religious; 3rdly, Because it deprives us of the means and
instruments of higher thought, of any adequate conception of the mind, of
knowledge, of conscience, of moral obligation.



O gar arche men o me oide, teleute de kai ta metaxu ex ou me oide
sumpeplektai, tis mechane ten toiauten omologian pote epistemen genesthai;
Plato Republic.

Monon gar auto legeiv, osper gumnon kai aperemomenon apo ton onton apanton,
adunaton. Soph.

Since the above essay first appeared, many books on Psychology have been
given to the world, partly based upon the views of Herbart and other German
philosophers, partly independent of them. The subject has gained in bulk
and extent; whether it has had any true growth is more doubtful. It begins
to assume the language and claim the authority of a science; but it is only
an hypothesis or outline, which may be filled up in many ways according to
the fancy of individual thinkers. The basis of it is a precarious one,--
consciousness of ourselves and a somewhat uncertain observation of the rest
of mankind. Its relations to other sciences are not yet determined: they
seem to be almost too complicated to be ascertained. It may be compared to
an irregular building, run up hastily and not likely to last, because its
foundations are weak, and in many places rest only on the surface of the
ground. It has sought rather to put together scattered observations and to
make them into a system than to describe or prove them. It has never
severely drawn the line between facts and opinions. It has substituted a
technical phraseology for the common use of language, being neither able to
win acceptance for the one nor to get rid of the other.

The system which has thus arisen appears to be a kind of metaphysic
narrowed to the point of view of the individual mind, through which, as
through some new optical instrument limiting the sphere of vision, the
interior of thought and sensation is examined. But the individual mind in
the abstract, as distinct from the mind of a particular individual and
separated from the environment of circumstances, is a fiction only. Yet
facts which are partly true gather around this fiction and are naturally
described by the help of it. There is also a common type of the mind which
is derived from the comparison of many minds with one another and with our
own. The phenomena of which Psychology treats are familiar to us, but they
are for the most part indefinite; they relate to a something inside the
body, which seems also to overleap the limits of space. The operations of
this something, when isolated, cannot be analyzed by us or subjected to
observation and experiment. And there is another point to be considered.
The mind, when thinking, cannot survey that part of itself which is used in
thought. It can only be contemplated in the past, that is to say, in the
history of the individual or of the world. This is the scientific method
of studying the mind. But Psychology has also some other supports,
specious rather than real. It is partly sustained by the false analogy of
Physical Science and has great expectations from its near relationship to
Physiology. We truly remark that there is an infinite complexity of the
body corresponding to the infinite subtlety of the mind; we are conscious
that they are very nearly connected. But in endeavouring to trace the
nature of the connexion we are baffled and disappointed. In our knowledge
of them the gulf remains the same: no microscope has ever seen into
thought; no reflection on ourselves has supplied the missing link between
mind and matter...These are the conditions of this very inexact science,
and we shall only know less of it by pretending to know more, or by
assigning to it a form or style to which it has not yet attained and is not
really entitled.

Experience shows that any system, however baseless and ineffectual, in our
own or in any other age, may be accepted and continue to be studied, if it
seeks to satisfy some unanswered question or is based upon some ancient
tradition, especially if it takes the form and uses the language of
inductive philosophy. The fact therefore that such a science exists and is
popular, affords no evidence of its truth or value. Many who have pursued
it far into detail have never examined the foundations on which it rests.
The have been many imaginary subjects of knowledge of which enthusiastic
persons have made a lifelong study, without ever asking themselves what is
the evidence for them, what is the use of them, how long they will last?
They may pass away, like the authors of them, and 'leave not a wrack
behind;' or they may survive in fragments. Nor is it only in the Middle
Ages, or in the literary desert of China or of India, that such systems
have arisen; in our own enlightened age, growing up by the side of Physics,
Ethics, and other really progressive sciences, there is a weary waste of
knowledge, falsely so-called. There are sham sciences which no logic has
ever put to the test, in which the desire for knowledge invents the
materials of it.

And therefore it is expedient once more to review the bases of Psychology,
lest we should be imposed upon by its pretensions. The study of it may
have done good service by awakening us to the sense of inveterate errors
familiarized by language, yet it may have fallen into still greater ones;
under the pretence of new investigations it may be wasting the lives of
those who are engaged in it. It may also be found that the discussion of
it will throw light upon some points in the Theaetetus of Plato,--the
oldest work on Psychology which has come down to us. The imaginary science
may be called, in the language of ancient philosophy, 'a shadow of a part
of Dialectic or Metaphysic' (Gorg.).

In this postscript or appendix we propose to treat, first, of the true
bases of Psychology; secondly, of the errors into which the students of it
are most likely to fall; thirdly, of the principal subjects which are
usually comprehended under it; fourthly, of the form which facts relating
to the mind most naturally assume.

We may preface the enquiry by two or three remarks:--

(1) We do not claim for the popular Psychology the position of a science at
all; it cannot, like the Physical Sciences, proceed by the Inductive
Method: it has not the necessity of Mathematics: it does not, like
Metaphysic, argue from abstract notions or from internal coherence. It is
made up of scattered observations. A few of these, though they may
sometimes appear to be truisms, are of the greatest value, and free from
all doubt. We are conscious of them in ourselves; we observe them working
in others; we are assured of them at all times. For example, we are
absolutely certain, (a) of the influence exerted by the mind over the body
or by the body over the mind: (b) of the power of association, by which
the appearance of some person or the occurrence of some event recalls to
mind, not always but often, other persons and events: (c) of the effect of
habit, which is strongest when least disturbed by reflection, and is to the
mind what the bones are to the body: (d) of the real, though not
unlimited, freedom of the human will: (e) of the reference, more or less
distinct, of our sensations, feelings, thoughts, actions, to ourselves,
which is called consciousness, or, when in excess, self-consciousness: (f)
of the distinction of the 'I' and 'Not I,' of ourselves and outward
objects. But when we attempt to gather up these elements in a single
system, we discover that the links by which we combine them are apt to be
mere words. We are in a country which has never been cleared or surveyed;
here and there only does a gleam of light come through the darkness of the

(2) These fragments, although they can never become science in the ordinary
sense of the word, are a real part of knowledge and may be of great value
in education. We may be able to add a good deal to them from our own
experience, and we may verify them by it. Self-examination is one of those
studies which a man can pursue alone, by attention to himself and the
processes of his individual mind. He may learn much about his own
character and about the character of others, if he will 'make his mind sit
down' and look at itself in the glass. The great, if not the only use of
such a study is a practical one,--to know, first, human nature, and,
secondly, our own nature, as it truly is.

(3) Hence it is important that we should conceive of the mind in the
noblest and simplest manner. While acknowledging that language has been
the greatest factor in the formation of human thought, we must endeavour to
get rid of the disguises, oppositions, contradictions, which arise out of
it. We must disengage ourselves from the ideas which the customary use of
words has implanted in us. To avoid error as much as possible when we are
speaking of things unseen, the principal terms which we use should be few,
and we should not allow ourselves to be enslaved by them. Instead of
seeking to frame a technical language, we should vary our forms of speech,
lest they should degenerate into formulas. A difficult philosophical
problem is better understood when translated into the vernacular.

I.a. Psychology is inseparable from language, and early language contains
the first impressions or the oldest experience of man respecting himself.
These impressions are not accurate representations of the truth; they are
the reflections of a rudimentary age of philosophy. The first and simplest
forms of thought are rooted so deep in human nature that they can never be
got rid of; but they have been perpetually enlarged and elevated, and the
use of many words has been transferred from the body to the mind. The
spiritual and intellectual have thus become separated from the material--
there is a cleft between them; and the heart and the conscience of man rise
above the dominion of the appetites and create a new language in which they
too find expression. As the differences of actions begin to be perceived,
more and more names are needed. This is the first analysis of the human
mind; having a general foundation in popular experience, it is moulded to a
certain extent by hierophants and philosophers. (See Introd. to Cratylus.)

b. This primitive psychology is continually receiving additions from the
first thinkers, who in return take a colour from the popular language of
the time. The mind is regarded from new points of view, and becomes
adapted to new conditions of knowledge. It seeks to isolate itself from
matter and sense, and to assert its independence in thought. It recognizes
that it is independent of the external world. It has five or six natural
states or stages:--(1) sensation, in which it is almost latent or
quiescent: (2) feeling, or inner sense, when the mind is just awakening:
(3) memory, which is decaying sense, and from time to time, as with a spark
or flash, has the power of recollecting or reanimating the buried past:
(4) thought, in which images pass into abstract notions or are intermingled
with them: (5) action, in which the mind moves forward, of itself, or
under the impulse of want or desire or pain, to attain or avoid some end or
consequence: and (6) there is the composition of these or the admixture or
assimilation of them in various degrees. We never see these processes of
the mind, nor can we tell the causes of them. But we know them by their
results, and learn from other men that so far as we can describe to them or
they to us the workings of the mind, their experience is the same or nearly
the same with our own.

c. But the knowledge of the mind is not to any great extent derived from
the observation of the individual by himself. It is the growing
consciousness of the human race, embodied in language, acknowledged by
experience, and corrected from time to time by the influence of literature
and philosophy. A great, perhaps the most important, part of it is to be
found in early Greek thought. In the Theaetetus of Plato it has not yet
become fixed: we are still stumbling on the threshold. In Aristotle the
process is more nearly completed, and has gained innumerable abstractions,
of which many have had to be thrown away because relative only to the
controversies of the time. In the interval between Thales and Aristotle
were realized the distinctions of mind and body, of universal and
particular, of infinite and infinitesimal, of idea and phenomenon; the
class conceptions of faculties and virtues, the antagonism of the appetites
and the reason; and connected with this, at a higher stage of development,
the opposition of moral and intellectual virtue; also the primitive
conceptions of unity, being, rest, motion, and the like. These divisions
were not really scientific, but rather based on popular experience. They
were not held with the precision of modern thinkers, but taken all together
they gave a new existence to the mind in thought, and greatly enlarged and
more accurately defined man's knowledge of himself and of the world. The
majority of them have been accepted by Christian and Western nations. Yet
in modern times we have also drifted so far away from Aristotle, that if we
were to frame a system on his lines we should be at war with ordinary
language and untrue to our own consciousness. And there have been a few
both in mediaeval times and since the Reformation who have rebelled against
the Aristotelian point of view. Of these eccentric thinkers there have
been various types, but they have all a family likeness. According to
them, there has been too much analysis and too little synthesis, too much
division of the mind into parts and too little conception of it as a whole
or in its relation to God and the laws of the universe. They have thought
that the elements of plurality and unity have not been duly adjusted. The
tendency of such writers has been to allow the personality of man to be
absorbed in the universal, or in the divine nature, and to deny the
distinction between matter and mind, or to substitute one for the other.
They have broken some of the idols of Psychology: they have challenged the
received meaning of words: they have regarded the mind under many points
of view. But though they may have shaken the old, they have not
established the new; their views of philosophy, which seem like the echo of
some voice from the East, have been alien to the mind of Europe.

d. The Psychology which is found in common language is in some degree
verified by experience, but not in such a manner as to give it the
character of an exact science. We cannot say that words always correspond
to facts. Common language represents the mind from different and even
opposite points of view, which cannot be all of them equally true (compare
Cratylus). Yet from diversity of statements and opinions may be obtained a
nearer approach to the truth than is to be gained from any one of them. It
also tends to correct itself, because it is gradually brought nearer to the
common sense of mankind. There are some leading categories or
classifications of thought, which, though unverified, must always remain
the elements from which the science or study of the mind proceeds. For
example, we must assume ideas before we can analyze them, and also a
continuing mind to which they belong; the resolution of it into successive
moments, which would say, with Protagoras, that the man is not the same
person which he was a minute ago, is, as Plato implies in the Theaetetus,
an absurdity.

e. The growth of the mind, which may be traced in the histories of
religions and philosophies and in the thoughts of nations, is one of the
deepest and noblest modes of studying it. Here we are dealing with the
reality, with the greater and, as it may be termed, the most sacred part of
history. We study the mind of man as it begins to be inspired by a human
or divine reason, as it is modified by circumstances, as it is distributed
in nations, as it is renovated by great movements, which go beyond the
limits of nations and affect human society on a scale still greater, as it
is created or renewed by great minds, who, looking down from above, have a
wider and more comprehensive vision. This is an ambitious study, of which
most of us rather 'entertain conjecture' than arrive at any detailed or
accurate knowledge. Later arises the reflection how these great ideas or
movements of the world have been appropriated by the multitude and found a
way to the minds of individuals. The real Psychology is that which shows
how the increasing knowledge of nature and the increasing experience of
life have always been slowly transforming the mind, how religions too have
been modified in the course of ages 'that God may be all and in all.' E
pollaplasion, eoe, to ergon e os nun zeteitai prostatteis.

f. Lastly, though we speak of the study of mind in a special sense, it may
also be said that there is no science which does not contribute to our
knowledge of it. The methods of science and their analogies are new
faculties, discovered by the few and imparted to the many. They are to the
mind, what the senses are to the body; or better, they may be compared to
instruments such as the telescope or microscope by which the discriminating
power of the senses, or to other mechanical inventions, by which the
strength and skill of the human body is so immeasurably increased.

II. The new Psychology, whatever may be its claim to the authority of a
science, has called attention to many facts and corrected many errors,
which without it would have been unexamined. Yet it is also itself very
liable to illusion. The evidence on which it rests is vague and
indefinite. The field of consciousness is never seen by us as a whole, but
only at particular points, which are always changing. The veil of language
intercepts facts. Hence it is desirable that in making an approach to the
study we should consider at the outset what are the kinds of error which
most easily affect it, and note the differences which separate it from
other branches of knowledge.

a. First, we observe the mind by the mind. It would seem therefore that
we are always in danger of leaving out the half of that which is the
subject of our enquiry. We come at once upon the difficulty of what is the
meaning of the word. Does it differ as subject and object in the same
manner? Can we suppose one set of feelings or one part of the mind to
interpret another? Is the introspecting thought the same with the thought
which is introspected? Has the mind the power of surveying its whole
domain at one and the same time?--No more than the eye can take in the
whole human body at a glance. Yet there may be a glimpse round the corner,
or a thought transferred in a moment from one point of view to another,
which enables us to see nearly the whole, if not at once, at any rate in
succession. Such glimpses will hardly enable us to contemplate from within
the mind in its true proportions. Hence the firmer ground of Psychology is
not the consciousness of inward feelings but the observation of external
actions, being the actions not only of ourselves, but of the innumerable
persons whom we come across in life.

b. The error of supposing partial or occasional explanation of mental
phenomena to be the only or complete ones. For example, we are disinclined
to admit of the spontaneity or discontinuity of the mind--it seems to us
like an effect without a cause, and therefore we suppose the train of our
thoughts to be always called up by association. Yet it is probable, or
indeed certain, that of many mental phenomena there are no mental
antecedents, but only bodily ones.

c. The false influence of language. We are apt to suppose that when there
are two or more words describing faculties or processes of the mind, there
are real differences corresponding to them. But this is not the case. Nor
can we determine how far they do or do not exist, or by what degree or kind
of difference they are distinguished. The same remark may be made about
figures of speech. They fill up the vacancy of knowledge; they are to the
mind what too much colour is to the eye; but the truth is rather concealed
than revealed by them.

d. The uncertain meaning of terms, such as Consciousness, Conscience,
Will, Law, Knowledge, Internal and External Sense; these, in the language
of Plato, 'we shamelessly use, without ever having taken the pains to
analyze them.'

e. A science such as Psychology is not merely an hypothesis, but an
hypothesis which, unlike the hypotheses of Physics, can never be verified.
It rests only on the general impressions of mankind, and there is little or
no hope of adding in any considerable degree to our stock of mental facts.

f. The parallelism of the Physical Sciences, which leads us to analyze the
mind on the analogy of the body, and so to reduce mental operations to the
level of bodily ones, or to confound one with the other.

g. That the progress of Physiology may throw a new light on Psychology is
a dream in which scientific men are always tempted to indulge. But however
certain we may be of the connexion between mind and body, the explanation
of the one by the other is a hidden place of nature which has hitherto been
investigated with little or no success.

h. The impossibility of distinguishing between mind and body. Neither in
thought nor in experience can we separate them. They seem to act together;
yet we feel that we are sometimes under the dominion of the one, sometimes
of the other, and sometimes, both in the common use of language and in
fact, they transform themselves, the one into the good principle, the other
into the evil principle; and then again the 'I' comes in and mediates
between them. It is also difficult to distinguish outward facts from the
ideas of them in the mind, or to separate the external stimulus to a
sensation from the activity of the organ, or this from the invisible
agencies by which it reaches the mind, or any process of sense from its
mental antecedent, or any mental energy from its nervous expression.

i. The fact that mental divisions tend to run into one another, and that
in speaking of the mind we cannot always distinguish differences of kind
from differences of degree; nor have we any measure of the strength and
intensity of our ideas or feelings.

j. Although heredity has been always known to the ancients as well as
ourselves to exercise a considerable influence on human character, yet we
are unable to calculate what proportion this birth-influence bears to
nurture and education. But this is the real question. We cannot pursue
the mind into embryology: we can only trace how, after birth, it begins to
grow. But how much is due to the soil, how much to the original latent
seed, it is impossible to distinguish. And because we are certain that
heredity exercises a considerable, but undefined influence, we must not
increase the wonder by exaggerating it.

k. The love of system is always tending to prevail over the historical
investigation of the mind, which is our chief means of knowing it. It
equally tends to hinder the other great source of our knowledge of the
mind, the observation of its workings and processes which we can make for

l. The mind, when studied through the individual, is apt to be isolated--
this is due to the very form of the enquiry; whereas, in truth, it is
indistinguishable from circumstances, the very language which it uses being
the result of the instincts of long-forgotten generations, and every word
which a man utters being the answer to some other word spoken or suggested
by somebody else.

III. The tendency of the preceding remarks has been to show that
Psychology is necessarily a fragment, and is not and cannot be a connected
system. We cannot define or limit the mind, but we can describe it. We
can collect information about it; we can enumerate the principal subjects
which are included in the study of it. Thus we are able to rehabilitate
Psychology to some extent, not as a branch of science, but as a collection
of facts bearing on human life, as a part of the history of philosophy, as
an aspect of Metaphysic. It is a fragment of a science only, which in all
probability can never make any great progress or attain to much clearness
or exactness. It is however a kind of knowledge which has a great interest
for us and is always present to us, and of which we carry about the
materials in our own bosoms. We can observe our minds and we can
experiment upon them, and the knowledge thus acquired is not easily
forgotten, and is a help to us in study as well as in conduct.

The principal subjects of Psychology may be summed up as follows:--

a. The relation of man to the world around him,--in what sense and within
what limits can he withdraw from its laws or assert himself against them
(Freedom and Necessity), and what is that which we suppose to be thus
independent and which we call ourselves? How does the inward differ from
the outward and what is the relation between them, and where do we draw the
line by which we separate mind from matter, the soul from the body? Is the
mind active or passive, or partly both? Are its movements identical with
those of the body, or only preconcerted and coincident with them, or is one
simply an aspect of the other?

b. What are we to think of time and space? Time seems to have a nearer
connexion with the mind, space with the body; yet time, as well as space,
is necessary to our idea of either. We see also that they have an analogy
with one another, and that in Mathematics they often interpenetrate. Space
or place has been said by Kant to be the form of the outward, time of the
inward sense. He regards them as parts or forms of the mind. But this is
an unfortunate and inexpressive way of describing their relation to us.
For of all the phenomena present to the human mind they seem to have most
the character of objective existence. There is no use in asking what is
beyond or behind them; we cannot get rid of them. And to throw the laws of
external nature which to us are the type of the immutable into the
subjective side of the antithesis seems to be equally inappropriate.

c. When in imagination we enter into the closet of the mind and withdraw
ourselves from the external world, we seem to find there more or less
distinct processes which may be described by the words, 'I perceive,' 'I
feel,' 'I think,' 'I want,' 'I wish,' 'I like,' 'I dislike,' 'I fear,' 'I
know,' 'I remember,' 'I imagine,' 'I dream,' 'I act,' 'I endeavour,' 'I
hope.' These processes would seem to have the same notions attached to
them in the minds of all educated persons. They are distinguished from one
another in thought, but they intermingle. It is possible to reflect upon
them or to become conscious of them in a greater or less degree, or with a
greater or less continuity or attention, and thus arise the intermittent
phenomena of consciousness or self-consciousness. The use of all of them
is possible to us at all times; and therefore in any operation of the mind
the whole are latent. But we are able to characterise them sufficiently by
that part of the complex action which is the most prominent. We have no
difficulty in distinguishing an act of sight or an act of will from an act
of thought, although thought is present in both of them. Hence the
conception of different faculties or different virtues is precarious,
because each of them is passing into the other, and they are all one in the
mind itself; they appear and reappear, and may all be regarded as the ever-
varying phases or aspects or differences of the same mind or person.

d. Nearest the sense in the scale of the intellectual faculties is memory,
which is a mode rather than a faculty of the mind, and accompanies all
mental operations. There are two principal kinds of it, recollection and
recognition,--recollection in which forgotten things are recalled or return
to the mind, recognition in which the mind finds itself again among things
once familiar. The simplest way in which we can represent the former to
ourselves is by shutting our eyes and trying to recall in what we term the
mind's eye the picture of the surrounding scene, or by laying down the book
which we are reading and recapitulating what we can remember of it. But
many times more powerful than recollection is recognition, perhaps because
it is more assisted by association. We have known and forgotten, and after
a long interval the thing which we have seen once is seen again by us, but
with a different feeling, and comes back to us, not as new knowledge, but
as a thing to which we ourselves impart a notion already present to us; in
Plato's words, we set the stamp upon the wax. Every one is aware of the
difference between the first and second sight of a place, between a scene
clothed with associations or bare and divested of them. We say to
ourselves on revisiting a spot after a long interval: How many things have
happened since I last saw this! There is probably no impression ever
received by us of which we can venture to say that the vestiges are
altogether lost, or that we might not, under some circumstances, recover
it. A long-forgotten knowledge may be easily renewed and therefore is very
different from ignorance. Of the language learnt in childhood not a word
may be remembered, and yet, when a new beginning is made, the old habit
soon returns, the neglected organs come back into use, and the river of
speech finds out the dried-up channel.

e. 'Consciousness' is the most treacherous word which is employed in the
study of the mind, for it is used in many senses, and has rarely, if ever,
been minutely analyzed. Like memory, it accompanies all mental operations,
but not always continuously, and it exists in various degrees. It may be
imperceptible or hardly perceptible: it may be the living sense that our
thoughts, actions, sufferings, are our own. It is a kind of attention
which we pay to ourselves, and is intermittent rather than continuous. Its
sphere has been exaggerated. It is sometimes said to assure us of our
freedom; but this is an illusion: as there may be a real freedom without
consciousness of it, so there may be a consciousness of freedom without the
reality. It may be regarded as a higher degree of knowledge when we not
only know but know that we know. Consciousness is opposed to habit,
inattention, sleep, death. It may be illustrated by its derivative
conscience, which speaks to men, not only of right and wrong in the
abstract, but of right and wrong actions in reference to themselves and
their circumstances.

f. Association is another of the ever-present phenomena of the human mind.
We speak of the laws of association, but this is an expression which is
confusing, for the phenomenon itself is of the most capricious and
uncertain sort. It may be briefly described as follows. The simplest case
of association is that of sense. When we see or hear separately one of two
things, which we have previously seen or heard together, the occurrence of
the one has a tendency to suggest the other. So the sight or name of a
house may recall to our minds the memory of those who once lived there.
Like may recall like and everything its opposite. The parts of a whole,
the terms of a series, objects lying near, words having a customary order
stick together in the mind. A word may bring back a passage of poetry or a
whole system of philosophy; from one end of the world or from one pole of
knowledge we may travel to the other in an indivisible instant. The long
train of association by which we pass from one point to the other,
involving every sort of complex relation, so sudden, so accidental, is one
of the greatest wonders of mind...This process however is not always
continuous, but often intermittent: we can think of things in isolation as
well as in association; we do not mean that they must all hang from one
another. We can begin again after an interval of rest or vacancy, as a new
train of thought suddenly arises, as, for example, when we wake of a
morning or after violent exercise. Time, place, the same colour or sound
or smell or taste, will often call up some thought or recollection either
accidentally or naturally associated with them. But it is equally
noticeable that the new thought may occur to us, we cannot tell how or why,
by the spontaneous action of the mind itself or by the latent influence of
the body. Both science and poetry are made up of associations or
recollections, but we must observe also that the mind is not wholly
dependent on them, having also the power of origination.

There are other processes of the mind which it is good for us to study when
we are at home and by ourselves,--the manner in which thought passes into
act, the conflict of passion and reason in many stages, the transition from
sensuality to love or sentiment and from earthly love to heavenly, the slow
and silent influence of habit, which little by little changes the nature of
men, the sudden change of the old nature of man into a new one, wrought by
shame or by some other overwhelming impulse. These are the greater
phenomena of mind, and he who has thought of them for himself will live and
move in a better-ordered world, and will himself be a better-ordered man.

At the other end of the 'globus intellectualis,' nearest, not to earth and
sense, but to heaven and God, is the personality of man, by which he holds
communion with the unseen world. Somehow, he knows not how, somewhere, he
knows not where, under this higher aspect of his being he grasps the ideas
of God, freedom and immortality; he sees the forms of truth, holiness and
love, and is satisfied with them. No account of the mind can be complete
which does not admit the reality or the possibility of another life.
Whether regarded as an ideal or as a fact, the highest part of man's nature
and that in which it seems most nearly to approach the divine, is a
phenomenon which exists, and must therefore be included within the domain
of Psychology.

IV. We admit that there is no perfect or ideal Psychology. It is not a
whole in the same sense in which Chemistry, Physiology, or Mathematics are
wholes: that is to say, it is not a connected unity of knowledge.
Compared with the wealth of other sciences, it rests upon a small number of
facts; and when we go beyond these, we fall into conjectures and verbal
discussions. The facts themselves are disjointed; the causes of them run
up into other sciences, and we have no means of tracing them from one to
the other. Yet it may be true of this, as of other beginnings of
knowledge, that the attempt to put them together has tested the truth of
them, and given a stimulus to the enquiry into them.

Psychology should be natural, not technical. It should take the form which
is the most intelligible to the common understanding, because it has to do
with common things, which are familiar to us all. It should aim at no more
than every reflecting man knows or can easily verify for himself. When
simple and unpretentious, it is least obscured by words, least liable to
fall under the influence of Physiology or Metaphysic. It should argue, not
from exceptional, but from ordinary phenomena. It should be careful to
distinguish the higher and the lower elements of human nature, and not
allow one to be veiled in the disguise of the other, lest through the
slippery nature of language we should pass imperceptibly from good to evil,
from nature in the higher to nature in the neutral or lower sense. It
should assert consistently the unity of the human faculties, the unity of
knowledge, the unity of God and law. The difference between the will and
the affections and between the reason and the passions should also be
recognized by it.

Its sphere is supposed to be narrowed to the individual soul; but it cannot
be thus separated in fact. It goes back to the beginnings of things, to
the first growth of language and philosophy, and to the whole science of
man. There can be no truth or completeness in any study of the mind which
is confined to the individual. The nature of language, though not the
whole, is perhaps at present the most important element in our knowledge of
it. It is not impossible that some numerical laws may be found to have a
place in the relations of mind and matter, as in the rest of nature. The
old Pythagorean fancy that the soul 'is or has in it harmony' may in some
degree be realized. But the indications of such numerical harmonies are
faint; either the secret of them lies deeper than we can discover, or
nature may have rebelled against the use of them in the composition of men
and animals. It is with qualitative rather than with quantitative
differences that we are concerned in Psychology. The facts relating to the
mind which we obtain from Physiology are negative rather than positive.
They show us, not the processes of mental action, but the conditions of
which when deprived the mind ceases to act. It would seem as if the time
had not yet arrived when we can hope to add anything of much importance to
our knowledge of the mind from the investigations of the microscope. The
elements of Psychology can still only be learnt from reflections on
ourselves, which interpret and are also interpreted by our experience of
others. The history of language, of philosophy, and religion, the great
thoughts or inventions or discoveries which move mankind, furnish the
larger moulds or outlines in which the human mind has been cast. From
these the individual derives so much as he is able to comprehend or has the
opportunity of learning.




Translated by Benjamin Jowett

PERSONS OF THE DIALOGUE: Socrates, Theodorus, Theaetetus.

Euclid and Terpsion meet in front of Euclid's house in Megara; they enter
the house, and the dialogue is read to them by a servant.

EUCLID: Have you only just arrived from the country, Terpsion?

TERPSION: No, I came some time ago: and I have been in the Agora looking
for you, and wondering that I could not find you.

EUCLID: But I was not in the city.

TERPSION: Where then?

EUCLID: As I was going down to the harbour, I met Theaetetus--he was being
carried up to Athens from the army at Corinth.

TERPSION: Was he alive or dead?

EUCLID: He was scarcely alive, for he has been badly wounded; but he was
suffering even more from the sickness which has broken out in the army.

TERPSION: The dysentery, you mean?


TERPSION: Alas! what a loss he will be!

EUCLID: Yes, Terpsion, he is a noble fellow; only to-day I heard some
people highly praising his behaviour in this very battle.

TERPSION: No wonder; I should rather be surprised at hearing anything else
of him. But why did he go on, instead of stopping at Megara?

EUCLID: He wanted to get home: although I entreated and advised him to
remain, he would not listen to me; so I set him on his way, and turned
back, and then I remembered what Socrates had said of him, and thought how
remarkably this, like all his predictions, had been fulfilled. I believe
that he had seen him a little before his own death, when Theaetetus was a
youth, and he had a memorable conversation with him, which he repeated to
me when I came to Athens; he was full of admiration of his genius, and said
that he would most certainly be a great man, if he lived.

TERPSION: The prophecy has certainly been fulfilled; but what was the
conversation? can you tell me?

EUCLID: No, indeed, not offhand; but I took notes of it as soon as I got
home; these I filled up from memory, writing them out at leisure; and
whenever I went to Athens, I asked Socrates about any point which I had
forgotten, and on my return I made corrections; thus I have nearly the
whole conversation written down.

TERPSION: I remember--you told me; and I have always been intending to ask
you to show me the writing, but have put off doing so; and now, why should
we not read it through?--having just come from the country, I should
greatly like to rest.

EUCLID: I too shall be very glad of a rest, for I went with Theaetetus as
far as Erineum. Let us go in, then, and, while we are reposing, the
servant shall read to us.

TERPSION: Very good.

EUCLID: Here is the roll, Terpsion; I may observe that I have introduced
Socrates, not as narrating to me, but as actually conversing with the
persons whom he mentioned--these were, Theodorus the geometrician (of
Cyrene), and Theaetetus. I have omitted, for the sake of convenience, the
interlocutory words 'I said,' 'I remarked,' which he used when he spoke of
himself, and again, 'he agreed,' or 'disagreed,' in the answer, lest the
repetition of them should be troublesome.

TERPSION: Quite right, Euclid.

EUCLID: And now, boy, you may take the roll and read.


SOCRATES: If I cared enough about the Cyrenians, Theodorus, I would ask
you whether there are any rising geometricians or philosophers in that part
of the world. But I am more interested in our own Athenian youth, and I
would rather know who among them are likely to do well. I observe them as
far as I can myself, and I enquire of any one whom they follow, and I see
that a great many of them follow you, in which they are quite right,
considering your eminence in geometry and in other ways. Tell me then, if
you have met with any one who is good for anything.

THEODORUS: Yes, Socrates, I have become acquainted with one very
remarkable Athenian youth, whom I commend to you as well worthy of your
attention. If he had been a beauty I should have been afraid to praise
him, lest you should suppose that I was in love with him; but he is no
beauty, and you must not be offended if I say that he is very like you; for
he has a snub nose and projecting eyes, although these features are less
marked in him than in you. Seeing, then, that he has no personal
attractions, I may freely say, that in all my acquaintance, which is very
large, I never knew any one who was his equal in natural gifts: for he has
a quickness of apprehension which is almost unrivalled, and he is
exceedingly gentle, and also the most courageous of men; there is a union
of qualities in him such as I have never seen in any other, and should
scarcely have thought possible; for those who, like him, have quick and
ready and retentive wits, have generally also quick tempers; they are ships
without ballast, and go darting about, and are mad rather than courageous;
and the steadier sort, when they have to face study, prove stupid and
cannot remember. Whereas he moves surely and smoothly and successfully in
the path of knowledge and enquiry; and he is full of gentleness, flowing on
silently like a river of oil; at his age, it is wonderful.

SOCRATES: That is good news; whose son is he?

THEODORUS: The name of his father I have forgotten, but the youth himself
is the middle one of those who are approaching us; he and his companions
have been anointing themselves in the outer court, and now they seem to
have finished, and are coming towards us. Look and see whether you know

SOCRATES: I know the youth, but I do not know his name; he is the son of
Euphronius the Sunian, who was himself an eminent man, and such another as
his son is, according to your account of him; I believe that he left a
considerable fortune.

THEODORUS: Theaetetus, Socrates, is his name; but I rather think that the
property disappeared in the hands of trustees; notwithstanding which he is
wonderfully liberal.

SOCRATES: He must be a fine fellow; tell him to come and sit by me.

THEODORUS: I will. Come hither, Theaetetus, and sit by Socrates.

SOCRATES: By all means, Theaetetus, in order that I may see the reflection
of myself in your face, for Theodorus says that we are alike; and yet if
each of us held in his hands a lyre, and he said that they were tuned
alike, should we at once take his word, or should we ask whether he who
said so was or was not a musician?

THEAETETUS: We should ask.

SOCRATES: And if we found that he was, we should take his word; and if
not, not?


SOCRATES: And if this supposed likeness of our faces is a matter of any
interest to us, we should enquire whether he who says that we are alike is
a painter or not?

THEAETETUS: Certainly we should.

SOCRATES: And is Theodorus a painter?

THEAETETUS: I never heard that he was.

SOCRATES: Is he a geometrician?

THEAETETUS: Of course he is, Socrates.

SOCRATES: And is he an astronomer and calculator and musician, and in
general an educated man?

THEAETETUS: I think so.

SOCRATES: If, then, he remarks on a similarity in our persons, either by
way of praise or blame, there is no particular reason why we should attend
to him.

THEAETETUS: I should say not.

SOCRATES: But if he praises the virtue or wisdom which are the mental
endowments of either of us, then he who hears the praises will naturally
desire to examine him who is praised: and he again should be willing to
exhibit himself.

THEAETETUS: Very true, Socrates.

SOCRATES: Then now is the time, my dear Theaetetus, for me to examine, and
for you to exhibit; since although Theodorus has praised many a citizen and
stranger in my hearing, never did I hear him praise any one as he has been
praising you.

THEAETETUS: I am glad to hear it, Socrates; but what if he was only in

SOCRATES: Nay, Theodorus is not given to jesting; and I cannot allow you
to retract your consent on any such pretence as that. If you do, he will
have to swear to his words; and we are perfectly sure that no one will be
found to impugn him. Do not be shy then, but stand to your word.

THEAETETUS: I suppose I must, if you wish it.

SOCRATES: In the first place, I should like to ask what you learn of
Theodorus: something of geometry, perhaps?


SOCRATES: And astronomy and harmony and calculation?

THEAETETUS: I do my best.

SOCRATES: Yes, my boy, and so do I; and my desire is to learn of him, or
of anybody who seems to understand these things. And I get on pretty well
in general; but there is a little difficulty which I want you and the
company to aid me in investigating. Will you answer me a question: 'Is
not learning growing wiser about that which you learn?'

THEAETETUS: Of course.

SOCRATES: And by wisdom the wise are wise?


SOCRATES: And is that different in any way from knowledge?


SOCRATES: Wisdom; are not men wise in that which they know?

THEAETETUS: Certainly they are.

SOCRATES: Then wisdom and knowledge are the same?


SOCRATES: Herein lies the difficulty which I can never solve to my
satisfaction--What is knowledge? Can we answer that question? What say
you? which of us will speak first? whoever misses shall sit down, as at a
game of ball, and shall be donkey, as the boys say; he who lasts out his
competitors in the game without missing, shall be our king, and shall have
the right of putting to us any questions which he pleases...Why is there no
reply? I hope, Theodorus, that I am not betrayed into rudeness by my love
of conversation? I only want to make us talk and be friendly and sociable.

THEODORUS: The reverse of rudeness, Socrates: but I would rather that you
would ask one of the young fellows; for the truth is, that I am unused to
your game of question and answer, and I am too old to learn; the young will
be more suitable, and they will improve more than I shall, for youth is
always able to improve. And so having made a beginning with Theaetetus, I
would advise you to go on with him and not let him off.

SOCRATES: Do you hear, Theaetetus, what Theodorus says? The philosopher,
whom you would not like to disobey, and whose word ought to be a command to
a young man, bids me interrogate you. Take courage, then, and nobly say
what you think that knowledge is.

THEAETETUS: Well, Socrates, I will answer as you and he bid me; and if I
make a mistake, you will doubtless correct me.

SOCRATES: We will, if we can.

THEAETETUS: Then, I think that the sciences which I learn from Theodorus--
geometry, and those which you just now mentioned--are knowledge; and I
would include the art of the cobbler and other craftsmen; these, each and
all of, them, are knowledge.

SOCRATES: Too much, Theaetetus, too much; the nobility and liberality of
your nature make you give many and diverse things, when I am asking for one
simple thing.

THEAETETUS: What do you mean, Socrates?

SOCRATES: Perhaps nothing. I will endeavour, however, to explain what I
believe to be my meaning: When you speak of cobbling, you mean the art or
science of making shoes?


SOCRATES: And when you speak of carpentering, you mean the art of making
wooden implements?


SOCRATES: In both cases you define the subject matter of each of the two


SOCRATES: But that, Theaetetus, was not the point of my question: we
wanted to know not the subjects, nor yet the number of the arts or
sciences, for we were not going to count them, but we wanted to know the
nature of knowledge in the abstract. Am I not right?

THEAETETUS: Perfectly right.

SOCRATES: Let me offer an illustration: Suppose that a person were to ask
about some very trivial and obvious thing--for example, What is clay? and
we were to reply, that there is a clay of potters, there is a clay of oven-
makers, there is a clay of brick-makers; would not the answer be


SOCRATES: In the first place, there would be an absurdity in assuming that
he who asked the question would understand from our answer the nature of
'clay,' merely because we added 'of the image-makers,' or of any other
workers. How can a man understand the name of anything, when he does not
know the nature of it?

THEAETETUS: He cannot.

SOCRATES: Then he who does not know what science or knowledge is, has no
knowledge of the art or science of making shoes?


SOCRATES: Nor of any other science?


SOCRATES: And when a man is asked what science or knowledge is, to give in
answer the name of some art or science is ridiculous; for the question is,
'What is knowledge?' and he replies, 'A knowledge of this or that.'


SOCRATES: Moreover, he might answer shortly and simply, but he makes an
enormous circuit. For example, when asked about the clay, he might have
said simply, that clay is moistened earth--what sort of clay is not to the

THEAETETUS: Yes, Socrates, there is no difficulty as you put the question.
You mean, if I am not mistaken, something like what occurred to me and to
my friend here, your namesake Socrates, in a recent discussion.

SOCRATES: What was that, Theaetetus?

THEAETETUS: Theodorus was writing out for us something about roots, such
as the roots of three or five, showing that they are incommensurable by the
unit: he selected other examples up to seventeen --there he stopped. Now
as there are innumerable roots, the notion occurred to us of attempting to
include them all under one name or class.

SOCRATES: And did you find such a class?

THEAETETUS: I think that we did; but I should like to have your opinion.

SOCRATES: Let me hear.

THEAETETUS: We divided all numbers into two classes: those which are made
up of equal factors multiplying into one another, which we compared to
square figures and called square or equilateral numbers;--that was one

SOCRATES: Very good.

THEAETETUS: The intermediate numbers, such as three and five, and every
other number which is made up of unequal factors, either of a greater
multiplied by a less, or of a less multiplied by a greater, and when
regarded as a figure, is contained in unequal sides;--all these we compared
to oblong figures, and called them oblong numbers.

SOCRATES: Capital; and what followed?

THEAETETUS: The lines, or sides, which have for their squares the
equilateral plane numbers, were called by us lengths or magnitudes; and the
lines which are the roots of (or whose squares are equal to) the oblong
numbers, were called powers or roots; the reason of this latter name being,
that they are commensurable with the former [i.e., with the so-called
lengths or magnitudes] not in linear measurement, but in the value of the
superficial content of their squares; and the same about solids.

SOCRATES: Excellent, my boys; I think that you fully justify the praises
of Theodorus, and that he will not be found guilty of false witness.

THEAETETUS: But I am unable, Socrates, to give you a similar answer about
knowledge, which is what you appear to want; and therefore Theodorus is a
deceiver after all.

SOCRATES: Well, but if some one were to praise you for running, and to say
that he never met your equal among boys, and afterwards you were beaten in
a race by a grown-up man, who was a great runner--would the praise be any
the less true?

THEAETETUS: Certainly not.

SOCRATES: And is the discovery of the nature of knowledge so small a
matter, as just now said? Is it not one which would task the powers of men
perfect in every way?

THEAETETUS: By heaven, they should be the top of all perfection!

SOCRATES: Well, then, be of good cheer; do not say that Theodorus was
mistaken about you, but do your best to ascertain the true nature of
knowledge, as well as of other things.

THEAETETUS: I am eager enough, Socrates, if that would bring to light the

SOCRATES: Come, you made a good beginning just now; let your own answer
about roots be your model, and as you comprehended them all in one class,
try and bring the many sorts of knowledge under one definition.

THEAETETUS: I can assure you, Socrates, that I have tried very often, when
the report of questions asked by you was brought to me; but I can neither
persuade myself that I have a satisfactory answer to give, nor hear of any
one who answers as you would have him; and I cannot shake off a feeling of

SOCRATES: These are the pangs of labour, my dear Theaetetus; you have
something within you which you are bringing to the birth.

THEAETETUS: I do not know, Socrates; I only say what I feel.

SOCRATES: And have you never heard, simpleton, that I am the son of a
midwife, brave and burly, whose name was Phaenarete?

THEAETETUS: Yes, I have.

SOCRATES: And that I myself practise midwifery?

THEAETETUS: No, never.

SOCRATES: Let me tell you that I do though, my friend: but you must not
reveal the secret, as the world in general have not found me out; and
therefore they only say of me, that I am the strangest of mortals and drive
men to their wits' end. Did you ever hear that too?


SOCRATES: Shall I tell you the reason?

THEAETETUS: By all means.

SOCRATES: Bear in mind the whole business of the midwives, and then you
will see my meaning better:--No woman, as you are probably aware, who is
still able to conceive and bear, attends other women, but only those who
are past bearing.

THEAETETUS: Yes, I know.

SOCRATES: The reason of this is said to be that Artemis--the goddess of
childbirth--is not a mother, and she honours those who are like herself;
but she could not allow the barren to be midwives, because human nature
cannot know the mystery of an art without experience; and therefore she
assigned this office to those who are too old to bear.

THEAETETUS: I dare say.

SOCRATES: And I dare say too, or rather I am absolutely certain, that the
midwives know better than others who is pregnant and who is not?

THEAETETUS: Very true.

SOCRATES: And by the use of potions and incantations they are able to
arouse the pangs and to soothe them at will; they can make those bear who
have a difficulty in bearing, and if they think fit they can smother the
embryo in the womb.


SOCRATES: Did you ever remark that they are also most cunning matchmakers,
and have a thorough knowledge of what unions are likely to produce a brave

THEAETETUS: No, never.

SOCRATES: Then let me tell you that this is their greatest pride, more
than cutting the umbilical cord. And if you reflect, you will see that the
same art which cultivates and gathers in the fruits of the earth, will be
most likely to know in what soils the several plants or seeds should be

THEAETETUS: Yes, the same art.

SOCRATES: And do you suppose that with women the case is otherwise?

THEAETETUS: I should think not.

SOCRATES: Certainly not; but midwives are respectable women who have a
character to lose, and they avoid this department of their profession,
because they are afraid of being called procuresses, which is a name given
to those who join together man and woman in an unlawful and unscientific
way; and yet the true midwife is also the true and only matchmaker.


SOCRATES: Such are the midwives, whose task is a very important one, but
not so important as mine; for women do not bring into the world at one time
real children, and at another time counterfeits which are with difficulty
distinguished from them; if they did, then the discernment of the true and
false birth would be the crowning achievement of the art of midwifery--you
would think so?

THEAETETUS: Indeed I should.

SOCRATES: Well, my art of midwifery is in most respects like theirs; but
differs, in that I attend men and not women; and look after their souls
when they are in labour, and not after their bodies: and the triumph of my
art is in thoroughly examining whether the thought which the mind of the
young man brings forth is a false idol or a noble and true birth. And like
the midwives, I am barren, and the reproach which is often made against me,
that I ask questions of others and have not the wit to answer them myself,
is very just--the reason is, that the god compels me to be a midwife, but
does not allow me to bring forth. And therefore I am not myself at all
wise, nor have I anything to show which is the invention or birth of my own
soul, but those who converse with me profit. Some of them appear dull
enough at first, but afterwards, as our acquaintance ripens, if the god is
gracious to them, they all make astonishing progress; and this in the
opinion of others as well as in their own. It is quite dear that they
never learned anything from me; the many fine discoveries to which they
cling are of their own making. But to me and the god they owe their
delivery. And the proof of my words is, that many of them in their
ignorance, either in their self-conceit despising me, or falling under the
influence of others, have gone away too soon; and have not only lost the
children of whom I had previously delivered them by an ill bringing up, but
have stifled whatever else they had in them by evil communications, being
fonder of lies and shams than of the truth; and they have at last ended by
seeing themselves, as others see them, to be great fools. Aristeides, the
son of Lysimachus, is one of them, and there are many others. The truants
often return to me, and beg that I would consort with them again--they are
ready to go to me on their knees--and then, if my familiar allows, which is
not always the case, I receive them, and they begin to grow again. Dire
are the pangs which my art is able to arouse and to allay in those who
consort with me, just like the pangs of women in childbirth; night and day
they are full of perplexity and travail which is even worse than that of
the women. So much for them. And there are others, Theaetetus, who come
to me apparently having nothing in them; and as I know that they have no
need of my art, I coax them into marrying some one, and by the grace of God
I can generally tell who is likely to do them good. Many of them I have
given away to Prodicus, and many to other inspired sages. I tell you this
long story, friend Theaetetus, because I suspect, as indeed you seem to
think yourself, that you are in labour--great with some conception. Come
then to me, who am a midwife's son and myself a midwife, and do your best
to answer the questions which I will ask you. And if I abstract and expose
your first-born, because I discover upon inspection that the conception
which you have formed is a vain shadow, do not quarrel with me on that
account, as the manner of women is when their first children are taken from
them. For I have actually known some who were ready to bite me when I
deprived them of a darling folly; they did not perceive that I acted from
goodwill, not knowing that no god is the enemy of man--that was not within
the range of their ideas; neither am I their enemy in all this, but it
would be wrong for me to admit falsehood, or to stifle the truth. Once
more, then, Theaetetus, I repeat my old question, 'What is knowledge?'--and
do not say that you cannot tell; but quit yourself like a man, and by the
help of God you will be able to tell.

THEAETETUS: At any rate, Socrates, after such an exhortation I should be
ashamed of not trying to do my best. Now he who knows perceives what he
knows, and, as far as I can see at present, knowledge is perception.

SOCRATES: Bravely said, boy; that is the way in which you should express
your opinion. And now, let us examine together this conception of yours,
and see whether it is a true birth or a mere wind-egg:--You say that
knowledge is perception?


SOCRATES: Well, you have delivered yourself of a very important doctrine
about knowledge; it is indeed the opinion of Protagoras, who has another
way of expressing it. Man, he says, is the measure of all things, of the
existence of things that are, and of the non-existence of things that are
not:--You have read him?

THEAETETUS: O yes, again and again.

SOCRATES: Does he not say that things are to you such as they appear to
you, and to me such as they appear to me, and that you and I are men?

THEAETETUS: Yes, he says so.

SOCRATES: A wise man is not likely to talk nonsense. Let us try to
understand him: the same wind is blowing, and yet one of us may be cold
and the other not, or one may be slightly and the other very cold?

THEAETETUS: Quite true.

SOCRATES: Now is the wind, regarded not in relation to us but absolutely,
cold or not; or are we to say, with Protagoras, that the wind is cold to
him who is cold, and not to him who is not?

THEAETETUS: I suppose the last.

SOCRATES: Then it must appear so to each of them?


SOCRATES: And 'appears to him' means the same as 'he perceives.'


SOCRATES: Then appearing and perceiving coincide in the case of hot and
cold, and in similar instances; for things appear, or may be supposed to
be, to each one such as he perceives them?


SOCRATES: Then perception is always of existence, and being the same as
knowledge is unerring?


SOCRATES: In the name of the Graces, what an almighty wise man Protagoras
must have been! He spoke these things in a parable to the common herd,
like you and me, but told the truth, 'his Truth,' (In allusion to a book of
Protagoras' which bore this title.) in secret to his own disciples.

THEAETETUS: What do you mean, Socrates?

SOCRATES: I am about to speak of a high argument, in which all things are
said to be relative; you cannot rightly call anything by any name, such as
great or small, heavy or light, for the great will be small and the heavy
light--there is no single thing or quality, but out of motion and change
and admixture all things are becoming relatively to one another, which
'becoming' is by us incorrectly called being, but is really becoming, for
nothing ever is, but all things are becoming. Summon all philosophers--
Protagoras, Heracleitus, Empedocles, and the rest of them, one after
another, and with the exception of Parmenides they will agree with you in
this. Summon the great masters of either kind of poetry--Epicharmus, the
prince of Comedy, and Homer of Tragedy; when the latter sings of

'Ocean whence sprang the gods, and mother Tethys,'

does he not mean that all things are the offspring, of flux and motion?

THEAETETUS: I think so.

SOCRATES: And who could take up arms against such a great army having
Homer for its general, and not appear ridiculous? (Compare Cratylus.)

THEAETETUS: Who indeed, Socrates?

SOCRATES: Yes, Theaetetus; and there are plenty of other proofs which will
show that motion is the source of what is called being and becoming, and
inactivity of not-being and destruction; for fire and warmth, which are
supposed to be the parent and guardian of all other things, are born of
movement and of friction, which is a kind of motion;--is not this the
origin of fire?


SOCRATES: And the race of animals is generated in the same way?

THEAETETUS: Certainly.

SOCRATES: And is not the bodily habit spoiled by rest and idleness, but
preserved for a long time by motion and exercise?


SOCRATES: And what of the mental habit? Is not the soul informed, and
improved, and preserved by study and attention, which are motions; but when
at rest, which in the soul only means want of attention and study, is
uninformed, and speedily forgets whatever she has learned?


SOCRATES: Then motion is a good, and rest an evil, to the soul as well as
to the body?


SOCRATES: I may add, that breathless calm, stillness and the like waste
and impair, while wind and storm preserve; and the palmary argument of all,
which I strongly urge, is the golden chain in Homer, by which he means the
sun, thereby indicating that so long as the sun and the heavens go round in
their orbits, all things human and divine are and are preserved, but if
they were chained up and their motions ceased, then all things would be
destroyed, and, as the saying is, turned upside down.

THEAETETUS: I believe, Socrates, that you have truly explained his

SOCRATES: Then now apply his doctrine to perception, my good friend, and
first of all to vision; that which you call white colour is not in your
eyes, and is not a distinct thing which exists out of them. And you must
not assign any place to it: for if it had position it would be, and be at
rest, and there would be no process of becoming.

THEAETETUS: Then what is colour?

SOCRATES: Let us carry the principle which has just been affirmed, that
nothing is self-existent, and then we shall see that white, black, and
every other colour, arises out of the eye meeting the appropriate motion,
and that what we call a colour is in each case neither the active nor the
passive element, but something which passes between them, and is peculiar
to each percipient; are you quite certain that the several colours appear
to a dog or to any animal whatever as they appear to you?

THEAETETUS: Far from it.

SOCRATES: Or that anything appears the same to you as to another man? Are
you so profoundly convinced of this? Rather would it not be true that it
never appears exactly the same to you, because you are never exactly the

THEAETETUS: The latter.

SOCRATES: And if that with which I compare myself in size, or which I
apprehend by touch, were great or white or hot, it could not become
different by mere contact with another unless it actually changed; nor
again, if the comparing or apprehending subject were great or white or hot,
could this, when unchanged from within, become changed by any approximation
or affection of any other thing. The fact is that in our ordinary way of
speaking we allow ourselves to be driven into most ridiculous and wonderful
contradictions, as Protagoras and all who take his line of argument would

THEAETETUS: How? and of what sort do you mean?

SOCRATES: A little instance will sufficiently explain my meaning: Here
are six dice, which are more by a half when compared with four, and fewer
by a half than twelve--they are more and also fewer. How can you or any
one maintain the contrary?

THEAETETUS: Very true.

SOCRATES: Well, then, suppose that Protagoras or some one asks whether
anything can become greater or more if not by increasing, how would you
answer him, Theaetetus?

THEAETETUS: I should say 'No,' Socrates, if I were to speak my mind in
reference to this last question, and if I were not afraid of contradicting
my former answer.

SOCRATES: Capital! excellent! spoken like an oracle, my boy! And if you
reply 'Yes,' there will be a case for Euripides; for our tongue will be
unconvinced, but not our mind. (In allusion to the well-known line of
Euripides, Hippol.: e gloss omomoch e de thren anomotos.)

THEAETETUS: Very true.

SOCRATES: The thoroughbred Sophists, who know all that can be known about
the mind, and argue only out of the superfluity of their wits, would have
had a regular sparring-match over this, and would have knocked their
arguments together finely. But you and I, who have no professional aims,
only desire to see what is the mutual relation of these principles,--
whether they are consistent with each or not.

THEAETETUS: Yes, that would be my desire.

SOCRATES: And mine too. But since this is our feeling, and there is
plenty of time, why should we not calmly and patiently review our own
thoughts, and thoroughly examine and see what these appearances in us
really are? If I am not mistaken, they will be described by us as
follows:--first, that nothing can become greater or less, either in number
or magnitude, while remaining equal to itself--you would agree?


SOCRATES: Secondly, that without addition or subtraction there is no
increase or diminution of anything, but only equality.

THEAETETUS: Quite true.

SOCRATES: Thirdly, that what was not before cannot be afterwards, without
becoming and having become.

THEAETETUS: Yes, truly.

SOCRATES: These three axioms, if I am not mistaken, are fighting with one
another in our minds in the case of the dice, or, again, in such a case as
this--if I were to say that I, who am of a certain height and taller than
you, may within a year, without gaining or losing in height, be not so
tall--not that I should have lost, but that you would have increased. In
such a case, I am afterwards what I once was not, and yet I have not
become; for I could not have become without becoming, neither could I have
become less without losing somewhat of my height; and I could give you ten
thousand examples of similar contradictions, if we admit them at all. I
believe that you follow me, Theaetetus; for I suspect that you have thought
of these questions before now.

THEAETETUS: Yes, Socrates, and I am amazed when I think of them; by the
Gods I am! and I want to know what on earth they mean; and there are times
when my head quite swims with the contemplation of them.

SOCRATES: I see, my dear Theaetetus, that Theodorus had a true insight
into your nature when he said that you were a philosopher, for wonder is
the feeling of a philosopher, and philosophy begins in wonder. He was not
a bad genealogist who said that Iris (the messenger of heaven) is the child
of Thaumas (wonder). But do you begin to see what is the explanation of
this perplexity on the hypothesis which we attribute to Protagoras?

THEAETETUS: Not as yet.

SOCRATES: Then you will be obliged to me if I help you to unearth the
hidden 'truth' of a famous man or school.

THEAETETUS: To be sure, I shall be very much obliged.

SOCRATES: Take a look round, then, and see that none of the uninitiated
are listening. Now by the uninitiated I mean the people who believe in
nothing but what they can grasp in their hands, and who will not allow that
action or generation or anything invisible can have real existence.

THEAETETUS: Yes, indeed, Socrates, they are very hard and impenetrable

SOCRATES: Yes, my boy, outer barbarians. Far more ingenious are the
brethren whose mysteries I am about to reveal to you. Their first
principle is, that all is motion, and upon this all the affections of which
we were just now speaking are supposed to depend: there is nothing but
motion, which has two forms, one active and the other passive, both in
endless number; and out of the union and friction of them there is
generated a progeny endless in number, having two forms, sense and the
object of sense, which are ever breaking forth and coming to the birth at
the same moment. The senses are variously named hearing, seeing, smelling;
there is the sense of heat, cold, pleasure, pain, desire, fear, and many
more which have names, as well as innumerable others which are without
them; each has its kindred object,--each variety of colour has a
corresponding variety of sight, and so with sound and hearing, and with the
rest of the senses and the objects akin to them. Do you see, Theaetetus,
the bearings of this tale on the preceding argument?

THEAETETUS: Indeed I do not.

SOCRATES: Then attend, and I will try to finish the story. The purport is
that all these things are in motion, as I was saying, and that this motion
is of two kinds, a slower and a quicker; and the slower elements have their
motions in the same place and with reference to things near them, and so
they beget; but what is begotten is swifter, for it is carried to fro, and
moves from place to place. Apply this to sense:--When the eye and the
appropriate object meet together and give birth to whiteness and the
sensation connatural with it, which could not have been given by either of
them going elsewhere, then, while the sight is flowing from the eye,
whiteness proceeds from the object which combines in producing the colour;
and so the eye is fulfilled with sight, and really sees, and becomes, not
sight, but a seeing eye; and the object which combined to form the colour
is fulfilled with whiteness, and becomes not whiteness but a white thing,
whether wood or stone or whatever the object may be which happens to be
coloured white. And this is true of all sensible objects, hard, warm, and
the like, which are similarly to be regarded, as I was saying before, not
as having any absolute existence, but as being all of them of whatever kind
generated by motion in their intercourse with one another; for of the agent
and patient, as existing in separation, no trustworthy conception, as they
say, can be formed, for the agent has no existence until united with the
patient, and the patient has no existence until united with the agent; and
that which by uniting with something becomes an agent, by meeting with some
other thing is converted into a patient. And from all these
considerations, as I said at first, there arises a general reflection, that
there is no one self-existent thing, but everything is becoming and in
relation; and being must be altogether abolished, although from habit and
ignorance we are compelled even in this discussion to retain the use of the
term. But great philosophers tell us that we are not to allow either the
word 'something,' or 'belonging to something,' or 'to me,' or 'this,' or
'that,' or any other detaining name to be used, in the language of nature
all things are being created and destroyed, coming into being and passing
into new forms; nor can any name fix or detain them; he who attempts to fix
them is easily refuted. And this should be the way of speaking, not only
of particulars but of aggregates; such aggregates as are expressed in the
word 'man,' or 'stone,' or any name of an animal or of a class. O
Theaetetus, are not these speculations sweet as honey? And do you not like
the taste of them in the mouth?

THEAETETUS: I do not know what to say, Socrates; for, indeed, I cannot
make out whether you are giving your own opinion or only wanting to draw me

SOCRATES: You forget, my friend, that I neither know, nor profess to know,
anything of these matters; you are the person who is in labour, I am the
barren midwife; and this is why I soothe you, and offer you one good thing
after another, that you may taste them. And I hope that I may at last help
to bring your own opinion into the light of day: when this has been
accomplished, then we will determine whether what you have brought forth is
only a wind-egg or a real and genuine birth. Therefore, keep up your
spirits, and answer like a man what you think.


SOCRATES: Then once more: Is it your opinion that nothing is but what
becomes?--the good and the noble, as well as all the other things which we
were just now mentioning?

THEAETETUS: When I hear you discoursing in this style, I think that there
is a great deal in what you say, and I am very ready to assent.

SOCRATES: Let us not leave the argument unfinished, then; for there still
remains to be considered an objection which may be raised about dreams and
diseases, in particular about madness, and the various illusions of hearing
and sight, or of other senses. For you know that in all these cases the
esse-percipi theory appears to be unmistakably refuted, since in dreams and
illusions we certainly have false perceptions; and far from saying that
everything is which appears, we should rather say that nothing is which

THEAETETUS: Very true, Socrates.

SOCRATES: But then, my boy, how can any one contend that knowledge is
perception, or that to every man what appears is?

THEAETETUS: I am afraid to say, Socrates, that I have nothing to answer,
because you rebuked me just now for making this excuse; but I certainly
cannot undertake to argue that madmen or dreamers think truly, when they
imagine, some of them that they are gods, and others that they can fly, and
are flying in their sleep.

SOCRATES: Do you see another question which can be raised about these
phenomena, notably about dreaming and waking?

THEAETETUS: What question?

SOCRATES: A question which I think that you must often have heard persons
ask:--How can you determine whether at this moment we are sleeping, and all
our thoughts are a dream; or whether we are awake, and talking to one
another in the waking state?

THEAETETUS: Indeed, Socrates, I do not know how to prove the one any more
than the other, for in both cases the facts precisely correspond;--and
there is no difficulty in supposing that during all this discussion we have
been talking to one another in a dream; and when in a dream we seem to be
narrating dreams, the resemblance of the two states is quite astonishing.

SOCRATES: You see, then, that a doubt about the reality of sense is easily
raised, since there may even be a doubt whether we are awake or in a dream.
And as our time is equally divided between sleeping and waking, in either
sphere of existence the soul contends that the thoughts which are present
to our minds at the time are true; and during one half of our lives we
affirm the truth of the one, and, during the other half, of the other; and
are equally confident of both.

THEAETETUS: Most true.

SOCRATES: And may not the same be said of madness and other disorders? the
difference is only that the times are not equal.

THEAETETUS: Certainly.

SOCRATES: And is truth or falsehood to be determined by duration of time?

THEAETETUS: That would be in many ways ridiculous.

SOCRATES: But can you certainly determine by any other means which of
these opinions is true?

THEAETETUS: I do not think that I can.

SOCRATES: Listen, then, to a statement of the other side of the argument,
which is made by the champions of appearance. They would say, as I
imagine--Can that which is wholly other than something, have the same
quality as that from which it differs? and observe, Theaetetus, that the
word 'other' means not 'partially,' but 'wholly other.'

THEAETETUS: Certainly, putting the question as you do, that which is
wholly other cannot either potentially or in any other way be the same.

SOCRATES: And must therefore be admitted to be unlike?


SOCRATES: If, then, anything happens to become like or unlike itself or
another, when it becomes like we call it the same--when unlike, other?

THEAETETUS: Certainly.

SOCRATES: Were we not saying that there are agents many and infinite, and
patients many and infinite?


SOCRATES: And also that different combinations will produce results which
are not the same, but different?

THEAETETUS: Certainly.

SOCRATES: Let us take you and me, or anything as an example:--There is
Socrates in health, and Socrates sick--Are they like or unlike?

THEAETETUS: You mean to compare Socrates in health as a whole, and
Socrates in sickness as a whole?

SOCRATES: Exactly; that is my meaning.

THEAETETUS: I answer, they are unlike.

SOCRATES: And if unlike, they are other?

THEAETETUS: Certainly.

SOCRATES: And would you not say the same of Socrates sleeping and waking,
or in any of the states which we were mentioning?


SOCRATES: All agents have a different patient in Socrates, accordingly as
he is well or ill.

THEAETETUS: Of course.

SOCRATES: And I who am the patient, and that which is the agent, will
produce something different in each of the two cases?

THEAETETUS: Certainly.

SOCRATES: The wine which I drink when I am in health, appears sweet and
pleasant to me?


SOCRATES: For, as has been already acknowledged, the patient and agent
meet together and produce sweetness and a perception of sweetness, which
are in simultaneous motion, and the perception which comes from the patient
makes the tongue percipient, and the quality of sweetness which arises out
of and is moving about the wine, makes the wine both to be and to appear
sweet to the healthy tongue.

THEAETETUS: Certainly; that has been already acknowledged.

SOCRATES: But when I am sick, the wine really acts upon another and a
different person?

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