and destroyed by indolence; and if the sun ceased
to move, "chaos would come again." Now apply this doctrine of "All
is motion" to the senses, and first of all to the sense of sight. The
colour of white, or any other colour, is neither in the eyes nor out of
them, but ever in motion between the object and the eye, and varying in
the case of every percipient. All is relative, and, as the followers of
Protagoras remark, endless contradictions arise when we deny this; e.g.
here are six dice; they are more than four and less than twelve; "more
and also less," would you not say?' 'Yes.' 'But Protagoras will retort:
"Can anything be more or less without addition or subtraction?"'

'I should say "No" if I were not afraid of contradicting my former
answer.'

'And if you say "Yes," the tongue will escape conviction but not the
mind, as Euripides would say?' 'True.' 'The thoroughbred Sophists, who
know all that can be known, would have a sparring match over this, but
you and I, who have no professional pride, want only to discover whether
our ideas are clear and consistent. And we cannot be wrong in saying,
first, that nothing can be greater or less while remaining equal;
secondly, that there can be no becoming greater or less without addition
or subtraction; thirdly, that what is and was not, cannot be without
having become. But then how is this reconcilable with the case of the
dice, and with similar examples?--that is the question.' 'I am often
perplexed and amazed, Socrates, by these difficulties.' 'That is because
you are a philosopher, for philosophy begins in wonder, and Iris is
the child of Thaumas. Do you know the original principle on which the
doctrine of Protagoras is based?' 'No.' 'Then I will tell you; but we
must not let the uninitiated hear, and by the uninitiated I mean the
obstinate people who believe in nothing which they cannot hold in their
hands. The brethren whose mysteries I am about to unfold to you are far
more ingenious. They maintain that all is motion; and that motion
has two forms, action and passion, out of which endless phenomena are
created, also in two forms--sense and the object of sense--which come to
the birth together. There are two kinds of motions, a slow and a fast;
the motions of the agent and the patient are slower, because they move
and create in and about themselves, but the things which are born of
them have a swifter motion, and pass rapidly from place to place.
The eye and the appr