GREEK BIOLOGY AND MEDICINE

are identical with one another, whilst others resemble, and others are analogous to each other." It was evident to Aristotle that the nutritive and motor life or soul could not exist without the body: " Plainly those principles whose activity is bodily cannot exist without a body, e.g., walking cannot exist without feet. For the same reason they cannot enter from out- side. . . ." But the final problem, — "a ques- tion of the greatest difficulty," says Aristotle, — is: " When and how and whence is a share in reason acquired by those animals that partic- ipate in this principle? " His answer is, that, unlike the nutritive and motor life, the reason, the rational soul, alone enters from without and " alone is divine, for no bodily activity has any connexion with the activity of reason." Modern biological psychology might not agree. Yet Aristotle's psychology was biolog- ical through and through. The soul with him was life; and life in its plant and animal activity was in and of the body and insepa- rable from it, save that only reason, the h'gher mind of man, was not of the body, but was divine. We still ask, what is divine? What is the body? What is reason?

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