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tions but if one only of the following properties, viz. mind, sensibility, locomotion, and rest, as well as the motion concerned in nutrition, growth, and decay be manifested in any object, we say that that object is alive. And, therefore, all plants seem to be alive, for they all appear to have within them a faculty and a principle by which they acquire growth and undergo decay in opposite directions; for they do not grow upwards exclusively, but they grow equally in both these and all other directions, and are alive throughout so long as they are able to imbibe nourishment. It is possible for nutrition to subsist inde-
pendently of the other functions, but the others cannot possibly, in mortal beings, subsist without it; and this is manifest in plants, since no other than it has been allotted to them. Thus, it is by this faculty of nutrition that life is manifested in living beings, but an animal is characterized above all by sensibility; for we say that creatures endowed with sensibility are not merely living beings but animals, although they may neither be motive nor change their locality. Touch is the sense first manifested in all creatures, and, as the nutritive faculty can be manifested inde-
pendently of Touch and other senses, so the sense of Touch can be manifested independently of any other. We call nutritive function that part of Vital Principle of which plants partake; but all animals appear besides