PLATONIC THEOLOGY, VOLUME 3: BOOKS IX-XI

BOOK IX

To demonstrate more clearly its immortality, the soul is proved
by way of the rational power to be not only undivided but
independent of the body

First proof: that the mind reflects upon itself.

By way of the rational power we have thus far proved that the soul
is an undivided and immortal form. We must next prove that it
does not depend on the body: and from this we can properly
conclude its immortality.

Divisible things do not reflect upon themselves. But if someone
were to argue that some divisible thing does reflect upon itself, we
will immediately ask: Is one part of this object reflecting upon an
other, or a part upon the whole, or the whole upon a part, or the
whole rather upon its whole self? If the first, then the same part is
not reflecting upon itself, since parts differ among themselves. If
the second or third, the same conclusion follows, for a part is one
thing, the whole another. Apparently, the fourth possibility is the
only one left: that the whole is reflecting upon the whole. This is
tantamount to saying that all the parts are reflecting upon all the
arts. Grant this. But after such reflecting is complete, let us then
ask whether in the object some part remains outside another part
or differs from another, or whether no part does? If a part remains,
then one part will exist in this position or in this manner,
another part in that, and so they will not yet be reflecting in turn
upon each other. But if no part remains, then assuredly no one
part in that object will be separate, or be distinguished, from
another. This object is so entirely indivisible that it is constituted...