In this connection I may refer to a suggestive chapter on "The Enjoyment of Pain" in Hirn's _Origins of Art_. "If we take into account," says Hirn, "the powerful stimulating effect which is produced by acute pain, we may easily understand why people submit to momentary unpleasantness for the sake of enjoying the subsequent excitement. This motive leads to the deliberate creation, not only of pain-sensations, but also of emotions in which pain enters as an element. The violent activity which is involved in the reaction against fear, and still more in that against anger, affords us a sensation of pleasurable excitement which is well worth the cost of the passing unpleasantness. It is, moreover, notorious that some persons have developed a peculiar art of making the initial pain of anger so transient that they can enjoy the active elements in it with almost undivided delight. Such an accomplishment is far more difficult in the case of sorrow.... The creation of pain-sensations may be explained as a desperate device for enhancing the intensity of the emotional state." The relation of pain and pleasure to emotion has been thoroughly discussed, I may add, by H.R. Marshall in his _Pain, Pleasure, and Æsthetics_. He contends that pleasure and pain are "general qualities, one of which must, and either of which may, belong to any fixed element of consciousness." "Pleasure," he considers, "is experienced whenever the physical activity coincident with the psychic state to which the pleasure is attached involves the use of surplus stored force." We can see, therefore, how, if pain acts as a stimulant to emotion, it becomes the servant of pleasure by supplying it with surplus stored force. This problem of pain is thus one of psychic dynamics. If we realize this we shall begin to understand the place of cruelty in life. "One ought to learn anew about cruelty," said Nietzsche (_Beyond Good and Evil_, 229), "and open one's eyes. Almost everything that we call 'higher culture' is based upon the spiritualizing and intensifying of _cruelty_.... Then, to be sure, we must put aside teaching the blundering psychology of former times, which could only teach with regard to cruelty that it originated at the sight of the suffering of _others_; there is an abundant, superabundant enjoyment even in one's own suffering, in causing one's own suffering." The element of paradox disappears from this statement if we realize that it is not a question of "cruelty," but of the dynamics of pain.