have preferred the study of nature to
man, or that he would have deemed the formation of the world and the
human frame to have the same interest which he ascribes to the mystery
of being and not-being, or to the great political problems which he
discusses in the Republic and the Laws. There are no speculations on
physics in the other dialogues of Plato, and he himself regards the
consideration of them as a rational pastime only. He is beginning to
feel the need of further divisions of knowledge; and is becoming aware
that besides dialectic, mathematics, and the arts, there is another
field which has been hitherto unexplored by him. But he has not as
yet defined this intermediate territory which lies somewhere between
medicine and mathematics, and he would have felt that there was as
great an impiety in ranking theories of physics first in the order of
knowledge, as in placing the body before the soul.

It is true, however, that the Timaeus is by no means confined to
speculations on physics. The deeper foundations of the Platonic
philosophy, such as the nature of God, the distinction of the sensible
and intellectual, the great original conceptions of time and space,
also appear in it. They are found principally in the first half of the
dialogue. The construction of the heavens is for the most part ideal;
the cyclic year serves as the connection between the world of absolute
being and of generation, just as the number of population in the
Republic is the expression or symbol of the transition from the ideal
to the actual state. In some passages we are uncertain whether we are
reading a description of astronomical facts or contemplating processes
of the human mind, or of that divine mind (Phil.) which in Plato is
hardly separable from it. The characteristics of man are transferred
to the world-animal, as for example when intelligence and knowledge are
said to be perfected by the circle of the Same, and true opinion by
the circle of the Other; and conversely the motions of the world-animal
reappear in man; its amorphous state continues in the child, and in both
disorder and chaos are gradually succeeded by stability and order. It
is not however to passages like these that Plato is referring when he
speaks of the uncertainty of his subject, but rather to the composition
of bodies, to the relations of colours, the nature of diseases, and the
like, about which he truly feels the lamentable ignorance prevailing in
his own age.