On The Soul   

the nutritive, we must go farther back and first give an account of

thinking or perceiving, for in the order of investigation the question

of what an agent does precedes the question, what enables it to do

what it does. If this is correct, we must on the same ground go yet

another step farther back and have some clear view of the objects of

each; thus we must start with these objects, e.g. with food, with what

is perceptible, or with what is intelligible.

It follows that first of all we must treat of nutrition and

reproduction, for the nutritive soul is found along with all the

others and is the most primitive and widely distributed power of soul,

being indeed that one in virtue of which all are said to have life.

The acts in which it manifests itself are reproduction and the use

of food-reproduction, I say, because for any living thing that has

reached its normal development and which is unmutilated, and whose

mode of generation is not spontaneous, the most natural act is the

production of another like itself, an animal producing an animal, a

plant a plant, in order that, as far as its nature allows, it may

partake in the eternal and divine. That is the goal towards which

all things strive, that for the sake of which they do whatsoever their

nature renders possible. The phrase 'for the sake of which' is

ambiguous; it may mean either (a) the end to achieve which, or (b) the

being in whose interest, the act is done. Since then no living thing

is able to partake in what is eternal and divine by uninterrupted

continuance (for nothing perishable can for ever remain one and the

same), it tries to achieve that end in the only way possible to it,

and success is possible in varying degrees; so it remains not indeed

as the self-same individual but continues its existence in something

like itself-not numerically but specifically one.

The soul is the cause or source of the living body. The terms

cause and source have many senses. But the soul is the cause of its

body alike in all three senses which we explicitly recognize. It is

(a) the source or origin of movement, it is (b) the end, it is (c) the