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CH. IV.] far as food is undigested, it is contrary nourished by contrary, and in so far as it is digested, it is like nourished by like. Thus, it is manifest that both these opinions are in one sense right, and in another wrong. But as nothing can be nourished which does not partake of life, so a living body may be regarded as a body which is nourished from having life; and thus nutrition is not in a casual, but a positive relation to a living body. There is an obvious distinction between nourishment and growth: in so far as a living body is quantity, it is capable of growth, and in so far as a something is matter and essence, it is nourishment; for it preserves the essence of the body, which exists so long as it can be nourished. Nourishment, however, does not generate that which is nourished, as it is the same as it; for it is already itself the essence, and nothing can generate, although it may preserve itself. Thus, it is the same faculty of Vital Principle which is able to preserve that, such as it may be, which contains it, and it is nourishment which renders it fit for its office; and, therefore, when deprived of nourishment, it can exist no longer.

Now, there are here three things or conditions—something to be nourished, something by which nourished, and something which nourishes. That which nourishes is the primal or nutritive faculty; that which is nourished is the body; and that by which nourished is food. And as things are correctly