How These Organic States Differ from Regular Emotions
Now why do we hesitate to call hunger, fatigue and the rest by the name of emotions? For two reasons, apparently. There are two salient differences between an organic state such as hunger, and an emotion such as anger.
Hunger we call a sensation because it is localized; we feel it in the region of the stomach. Thirst we localize in the throat, muscular fatigue in the fatigued muscles, and there are several other organic states that come to us as sensations from particular organs. This is not entirely true of drowsiness or euphoria, but it is still less true of the emotions, which we feel as in us, rather than in any part of us. We "feel mad all over", and we feel glad or sorry all over. It is true that, traditionally, the heart is the seat of the emotions, which means, no doubt, that they are felt in the region of the heart more than elsewhere; and other ancient "seats", in the bowels or diaphragm, agree to this extent that they point to the interior of the trunk as the general location where the emotions are felt. But at best the location of emotions is much less definite than that of the sensations of fatigue or hunger.
The second difference between the emotions and the other organic states comes to light when we notice their causes. Thirst, as an organic state, is a lack of water resulting [{121}] from perspiration, etc.; hunger as an organic state results from using up the food previously eaten; fatigue results from prolonged muscular activity. Each of these organic states results naturally from some internal bodily process; while, on the contrary, the exciting cause of an emotion is usually something external which has nothing directly to do with the internal state of the body. Here I am, perfectly calm and normal, my organic state neutral, when some one insults me and throws me into a state of rage; this queer state seems to be inside me, specially in the trunk. Now how can the sound of the insulting person's voice produce any change in my insides? Evidently, by way of the auditory nerve, the brain and lower centers, and the motor nerves to the interior. While, then, organic states of the hunger class result directly from internal physiological processes, the organic state in an emotion is aroused by the brain, the brain itself being aroused by some stimulus, usually external.