To understand Aristotle's doctrine of the soul. we must remember that the soul is the "form" of the
body, and that spatial shape is one kind of "form." What is there in common is hte conferring of
unity upon a certain amount of matter. The part of a block of marble which afterwards becomes a
statue is, as yet, not sparated from the rest of the marble; it is not yet a "thing," and has not yet any
unity. After the sculptor has made the statue, it has unity, which it derives from its shape. Now the
esential feature of the soul, in virtue of which it is the "form" of the body, is that it makes the body
an organic whole, having purposes as a unit. A single organ has purposes lying outside itself; the
eye, in isolation, cannot see. Thus many things can be said in which an animal or plant as a whole
is the subject, which cannot be said about any part of it. It is in this sense that organization, or
form, confers substantiality. That which confers substantiality upon a plant or animal is what
Aristotle calls it "soul." But "mind" is something different, less intimately bound up with the
body; perhaps it is a part of the soul, but it is possessed by only a small minority of living beings
(415a). Mind as speculation cannot be the cause of movement, for it never thinks about what is
practicable, and never says what is to be avoided or what pursued (432b).
A similar doctrine, though with a slight change of terminology, is set forth in the Nicomachean
Ethics. There is in the soul one element that is rational, and that is irrational. The irrational part is
twofold: the vegetative, which is found in everything living, even in plants, and the appetitive,
which exists in all animals (1102b). The life of the rational soul consists in contemplation, which
is the completehappiness of man, though not fully attainable. "Such a life would be too high for
man; for it is not in so far as he is man that he will live so, but in so far as something divine is
present in him; and by so much as this is superior to our composite nature is its activity superior to
that which is the exercise of the other kind of virtue (the practical kind). If reason is divine, then,
in comparison with man, the life in accordance with it is divine in comparison in human life. But
we must not follow those who advise us, being men, to think of human things, and being mortal,
of mortal things, but must, so far as we can, make ourselves immortal, and strain every nerve ot
live in accordance with the best thing in us; for even if it be small in bulk,