The instinctive motor activities characteristic of the various emotions may be classified under two headings: excitation and depression. The difference is especially noticeable in unpleasant emotions: anger is an emotion of excitement; fear, as a rule, of depression. But this distinction is not entirely absent in pleasant emotions. The joy of a grateful memory is characterized, not indeed by depression, but by a restfulness very distinct from the excited joy of expectation or the delight at a present experience, although the pleasantness felt may be of exactly the same degree of intensity. A careful analysis of these motor activities must distinguish, not only excitement and depression, but also their occurrence in either the skeletal or the involuntary muscles, the muscles of the vascular system. Thus one may distinguish four classes of emotions, as characterized chiefly by heightened activity of the skeletal or of the vascular muscles, or by weakened activity of the skeletal or of the vascular muscles. Symptoms resulting from abnormal contraction or relaxation of the vascular muscles are, for example, a person’s growing pallid, or blushing, and the corresponding sensations of cold and warmth. Two other concepts relating to the emotional life deserve to be mentioned, temperament and passion. Temperaments are inherited tendencies of the life of feeling in special directions. Since ancient times four have been distinguished: the sanguine, bilious (choleric), melancholic (atrabilious), phlegmatic (lymphatic). The ancients held that temperament is conditioned on the predominance of one of the four humors, the blood, lymph, yellow bile, and black bile. This is of course pure speculation of a prescientific period. But the distinction of the four classes agrees well with common observation, although mixed forms of temperament are more common than the pure types. People are either optimistically or pessimistically inclined. The sanguine and the phlegmatic are the optimists, the bilious and the melancholic the pessimists. On the other hand, some people are excitable, impetuous, others are not easily aroused. The sanguine and the bilious are quickly excited, the melancholic and the phlegmatic are calm and sluggish. Passions are acquired dispositions toward special kinds of pleasant experiences. We might say that they are foreseeing, voluntary emotions. We speak of the passion of the gambler, the smoker, the collector, the lover. One may also compare an emotion with an acute disease, a passion with a chronic disease. Animals, too, possess emotions, as joy, fear, and rage. But it seems that they are not sufficiently capable of anticipating emotions to be said to possess passions. QUESTIONS 186. How are emotions defined? 187. How does an emotion influence coherent thought? 188. How are moods defined? 189. Mention a number of moods and an equal number of emotions, each comparable to one of the moods.