republic (books 6 - 10)
And must not the soul be perplexed at this intimation which
the sense gives of a hard which is also soft? What, again, is
the meaning of light and heavy, if that which is light is also
heavy, and that which is heavy, light?
Yes, he said, these intimations which the soul receives are
very curious and require to be explained.
Yes, I said, and in these perplexities the soul naturally sum-
mons to her aid calculation and intelligence, that she may see
whether the several objects announced to her are one or two.
And if they turn out to be two, is not each of them one and
And if each is one, and both are two, she will conceive the
two as in a state of division, for if they were undivided they
could only be conceived of as one?
The eye certainly did see both small and great, but only in
a confused manner; they were not distinguished.
Whereas the thinking mind, intending to light up the chaos,
was compelled to reverse the process, and look at small and
great as separate and not confused.
Was not this the beginning of the inquiry, "What is great?"
and "What is small?"
And thus arose the distinction of the visible and the intel-
This was what I meant when I spoke of impressions which
invited the intellect, or the reverse--those which are simul-
taneous with opposite impressions, invite thought; those which
are not simultaneous do not.
I understand, he said, and agree with you.
And to which class do unity and number belong?
I do not know, he replied.
Think a little and you will see that what has preceded will
supply the answer; for if simple unity could be adequately per-
ceived by the sight or by any other sense, then, as we were say-
ing in the case of the finger, there would be nothing to attract
toward being; but when there is some contradiction always
present, and one is the reverse of one and involves the concep-