On The Soul
universal; or rather it is both, but the one does so while it
remains in a state more like rest, while the other partakes in
The nutritive soul then must be possessed by everything that is
alive, and every such thing is endowed with soul from its birth to its
death. For what has been born must grow, reach maturity, and decay-all
of which are impossible without nutrition. Therefore the nutritive
faculty must be found in everything that grows and decays.
But sensation need not be found in all things that live. For it is
impossible for touch to belong either (1) to those whose body is
uncompounded or (2) to those which are incapable of taking in the
forms without their matter.
But animals must be endowed with sensation, since Nature does
nothing in vain. For all things that exist by Nature are means to an
end, or will be concomitants of means to an end. Every body capable of
forward movement would, if unendowed with sensation, perish and fail
to reach its end, which is the aim of Nature; for how could it
obtain nutriment? Stationary living things, it is true, have as
their nutriment that from which they have arisen; but it is not
possible that a body which is not stationary but produced by
generation should have a soul and a discerning mind without also
having sensation. (Nor yet even if it were not produced by generation.
Why should it not have sensation? Because it were better so either for
the body or for the soul? But clearly it would not be better for
either: the absence of sensation will not enable the one to think
better or the other to exist better.) Therefore no body which is not
stationary has soul without sensation.
But if a body has sensation, it must be either simple or compound.
And simple it cannot be; for then it could not have touch, which is