One step further: In the description of the conduct of anthropoid apes which are kept in menageries, etc., especial intelligence is assigned to those who know how to draw a blanket over themselves as protection against cold. The same action is held to be a sign of intelligence in very young children.
Still more thoroughly graded is the attitude toward pain, inasmuch as barely a trace of intelligence is required, in order to know that it is necessary to wipe away a hot liquid drop that has fallen on the body. Every physiological text-book mentions the fact that a decapitated frog makes such wiping movements when it is wet with acid. From this unconscious activity of the understanding to the technically highest-developed treatment of a burn, a whole series of progressively higher expressions of intelligence may be interpolated, a series so great as to defy counting.
Now take another, still animal, but more highly-developed feeling, for example, the feeling of comfort. We lay a cat on a soft bolster—she stretches herself, spreads and thins herself out, in order to bring as many nerve termini as possible into contact with the pleasant stimuli of the bolster. This behavior of the cat may be construed as instinctive, also as the aboriginal source of the sense of comfort and as leading to luxury in comfort, the stage of comfort which Roscher calls highest. (I. Luxury in eating and drinking. II. Luxury in dress. III. Luxury in comfort.)
Therefore we may say that the reaction of the understanding to the physiological stimulus aims to set it aside when it is unpleasant, and to increase and exhaust it when it is pleasant, and that in a certain sense both coincide (the ousting of unpleasant darkness is equivalent to the introduction of pleasant light). We may therefore say generally, that feeling is a physiological stimulus indivisibly connected with the understanding’s sensitive attitude thereto. Of course there is a far cry from instinctive exclusion and inclusion to the most refined defensive preparation or interpretation, but the differences which lie next to each, on either side, are only differences in degree.
Now let us think of some so-called higher feeling and consider a special case of it. I meet for the first time a man who is unpleasantly marked, e.g., with badly colored hair. This stimulates my eyes disagreeably, and I seek either by looking away or by wishing the man away to protect myself from this physiologically-inimical influence, which already eliminates all feeling of friendship for this harmless individual. Now I see that the man is torturing an animal,—I do not like to see this, it affects me painfully; hence I wish him out of the way still more energetically. If he goes on so, adding one disagreeable characteristic to another, I might break his bones to stop him, bind him in chains to hinder him; I even might kill him, to save myself the unpleasant excitation he causes me. I strain my intelligence to think of some means of opposing him, and clearly, in this case, also, physiological stimulus and activity of the understanding are invincibly united.
The emotion of anger is rather more difficult to explain. But it is not like suddenly-exploding hatred, for it is acute, while hatred is chronic. I might be angry with my beloved child. But though at the moment of anger, the expression is identical with that of hatred, it is also transitive. In the extremest cases the negating action aims to destroy the stimulus. This is the most radical means of avoiding physiological excitation, and hence I tear in pieces a disagreeable letter, or stamp to powder the object on which I have hurt myself. Where persons are involved, I proceed either directly or symbolically when I can not, or may not, get my hands on the responsible one.
The case is the same with feeling of attraction. I own a dog, he has beautiful lines which are pleasant to my eye, he has a bell-like bark that stimulates my ear pleasantly, he has a soft coat which is pleasant to my stroking hand, I know that in case of need the dog will protect me (and that is a calming consideration), I know that he may be otherwise of use to me—in short my understanding tells me all kinds of pleasant things about the beast. Hence I like to have him near me; i.e., I like him. The same explanation may be applied to all emotions of inclination or repulsion. Everywhere we find the emotion as physiological stimulus in indivisible union with a number of partly known, partly unknown functions of the understanding. The unknown play an important rôle. They are serial understandings, i.e., inherited from remote ancestors, and are characterized by the fact that they lead us to do the things we do when we recognize intelligently any event and its requirements.
When one gets thirsty, he drinks. Cattle do the same. And they drink even when nobody has told them to, because this is an inherited action of countless years. If a man is, however, to proceed intelligently about his drinking, he will say, “By drying, or other forms of segregation, the water will be drawn from the cells of my body, they will become arid, and will no longer be sufficiently elastic to do their work. If, now, by way of my stomach, through endosmosis and exosmosis, I get them more water, the proper conditions will return.” The consequences of this form of consideration will not be different from the instinctive action of the most elementary of animals—the wise man and the animal drink. So the whole content of every emotion is physiological stimulation and function of the understanding.
And what good is all this to the criminal lawyer? Nobody doubts that both prisoners and witnesses are subject to the powerful influence of emotional expression. Nobody doubts that the determination, interpretation, and judgment of these expressions are as difficult as they are important to the judge. And when we consider these emotions as especial conditions of the mind it is indubitable that they are able to cause still greater difficulty because of their elusiveness, their very various intensity, and their confused effect. Once, however, we think of them as functions of the understanding, we have, in its activities, something better known, something rather more disciplined, which offers very many fewer difficulties in the judgment concerning the fixed form in which it acts. Hence, every judgment of an emotional state must be preceded by a reconstruction in terms of the implied functions of the understanding. Once this is done, further treatment is no longer difficult.