General Sense

We call general sense that faculty through which we receive knowledge not of external objects, but of the various states or needs of the body, those that tend toward its sustenance. Through this we receive knowledge of such and such a condition—the health of the body, cold, heat, pain, pricking, hunger, thirst, satiety, necessity, and other things. This sensation is found common to both humans and animals. But although the form of sensation appears on the whole similar, it differs internally, that is, morally; for while in humans the sensation of aroused feelings is transmitted to the rational soul, in animals the sensation of aroused feelings is referred to an irrational intellect; therefore, while the human person does not do what is necessary, but what he wishes, the animal in acting does what sensation dictates; nor is the will questioned at all; for it does not exist; and it always acts without delay and without postponement, while the human person delays, lingers, and resists. The animal seeking shelter in shade does so by necessity, not by choice, because it finds rest in it, and there is nothing wonderful about this if it is guided by instinct toward this action; for divine providence has granted all animals commonly the sensation of pleasure for the preservation of their life. All animals feel warmth and cold; both arouse irritation in the general sense, and experience guides toward the place where the irritation is relieved. Migratory birds do the same; but what shows this to be instinctive rather than rational action is that they resort to suitable regions before they even know the necessity, the place, or its usefulness. The same is observed in fish; most animals prepare their dwellings suitable for the temperatures of the climates where they find themselves, before they have even recognized them. Insects do the same before atmospheric changes, anticipating them and seeking a safe location. Certainly their activities are not rational, because there are no reasons to support the opposite; therefore instinct is what operates in them, not reason. No similarity therefore exists between the activities of the human person and the animal; let us see now if such a thing exists in the activities of the specific sense.