Further, of the ways in which we prove that the Forms exist,
none is convincing; for from some no inference necessarily follows,
and from some arise Forms even of things of which we think there are
no Forms. For according to the arguments from the existence of the
sciences there will be Forms of all things of which there are sciences
and according to the 'one over many' argument there will be Forms even
of negations, and according to the argument that there is an object
for thought even when the thing has perished, there will be Forms of
perishable things; for we have an image of these. Further, of the more
accurate arguments, some lead to Ideas of relations, of which we say
there is no independent class, and others introduce the 'third man'.

    And in general the arguments for the Forms destroy the things
for whose existence we are more zealous than for the existence of
the Ideas; for it follows that not the dyad but number is first,
i.e. that the relative is prior to the absolute,-besides all the other
points on which certain people by following out the opinions held
about the Ideas have come into conflict with the principles of the
theory.

    Further, according to the assumption on which our belief in the
Ideas rests, there will be Forms not only of substances but also of
many other things (for the concept is single not only in the case of
substances but also in the other cases, and there are sciences not
only of substance but also of other things, and a thousand other
such difficulties confront them). But according to the necessities
of the case and the opinions held about the Forms, if Forms can be
shared in there must be Ideas of substances only. For they are not
shared in incidentally, but a thing must share in its Form as in
something not predicated of a subject (by 'being shared in
incidentally' I mean that e.g. if a thing shares in 'double itself',
it shares also in 'eternal', but incidentally; for 'eternal' happens
to be predicable of the 'double'). Therefore the Forms will be
substance; but the same terms indicate substance in this and in the
ideal world (or what will be the meaning of saying that there is
something apart from the particulars-the one over many?). And if the
Ideas and the particulars that share in them have the same form, there
will be something common to these; for why should '2' be one and the
same in the perishable 2's or in those which are many but eternal, and
not the same in the '2' itself' as in the particular 2? But if they
have not the same form, they must have only the name in common, and it
is as if one were to call both Callias and a wooden image a 'man',
without observing any community between them.

    Above all one might discuss the question what on earth the Forms
contribute to sensible things, either to those that are eternal or
to those that come into being and cease to be. For they cause
neither movement nor any change in them. But again they help in no
wise either towards the knowledge of the other things (for they are
not even the substance of these, else they would have been in them),
or towards their being, if they are not in the particulars which share
in them; though if they were, they might be thought to be causes, as
white causes whiteness in a white object by entering into its
composition. But this argument, which first Anaxagoras and later
Eudoxus and certain others used, is very easily upset; for it is not
difficult to collect many insuperable objections to such a view.

    But, further, all other things cannot come from the Forms in any
of the usual senses of 'from'. And to say that they are patterns and
the other things share in them is to use empty words and poetical
metaphors. For what is it that works, looking to the Ideas? And
anything can either be, or become, like another without being copied
from it, so that whether Socrates or not a man Socrates like might
come to be; and evidently this might be so even if Socrates were
eternal. And there will be several patterns of the same thing, and
therefore several Forms; e.g. 'animal' and 'two-footed' and also
'man himself' will be Forms of man. Again, the Forms are patterns
not only sensible things, but of Forms themselves also; i.e. the
genus, as genus of various species, will be so; therefore the same
thing will be pattern and copy.

    Again, it would seem impossible that the substance and that of
which it is the substance should exist apart; how, therefore, could
the Ideas, being the substances of things, exist apart? In the Phaedo'
the case is stated in this way-that the Forms are causes both of being
and of becoming; yet when the Forms exist, still the things that share
in them do not come into being, unless there is something to originate
movement; and many other things come into being (e.g. a house or a
ring) of which we say there are no Forms. Clearly, therefore, even the
other things can both be and come into being owing to such causes as
produce the things just mentioned.

    Again, if the Forms are numbers, how can they be causes? Is it
because existing things are other numbers, e.g. one number is man,
another is Socrates, another Callias? Why then are the one set of
numbers causes of the other set? It will not make any difference
even if the former are eternal and the latter are not. But if it is
because things in this sensible world (e.g. harmony) are ratios of
numbers, evidently the things between which they are ratios are some
one class of things. If, then, this--the matter--is some definite
thing, evidently the numbers themselves too will be ratios of
something to something else. E.g. if Callias is a numerical ratio
between fire and earth and water and air, his Idea also will be a
number of certain other underlying things; and man himself, whether it
is a number in a sense or not, will still be a numerical ratio of
certain things and not a number proper, nor will it be a of number
merely because it is a numerical ratio.

    Again, from many numbers one number is produced, but how can one