1. When its physiological concomitants present themselves with extraordinary intensity (I think we should add, or an extraordinary depression). 2. When it takes place without sufficient determining cause. 3. When its effects are unreasonably prolonged.[41] Footnote 41: Féré, _Pathologie des Émotions_, p. 223. These three signs, which I shall call respectively abnormal reaction by excess or defect, disproportion (apparent) between cause and effect, and chronicity, will frequently be of service to us in the study of the emotions. For the moment we are only treating of pleasure and pain. I. Beginning with pleasure, I shall first examine a typical case studied by several physiologists, who have not furnished any, to me, satisfactory explanation. I mean the special state which has been called “the luxury of pity” (Spencer), pleasure in pain (Bouillier), and which it would be more accurate to call “the pleasure of pain.” It consists in being pleased with one’s own suffering and tasting it like a pleasure. This disposition of the mind is not, as one might think, peculiar to _blasé_ persons and to epochs of refined civilisation; it seems inherent in humanity the moment it emerges from barbarism. Bouillier[42] has quoted from the ancient writers passages referring to it, not only in Lucretius, Seneca, and other moralists, but in the Homeric poems, which reflect a very primitive civilisation, yet in which a man “rejoices in his tears.” Parallel passages might have been found in the Bible, and also, I suppose, in the epics of ancient India. We have not, therefore, to deal with a rare phenomenon, though it becomes more frequent as we advance in civilisation. Footnote 42: Bouillier, _Du plaisir et de la douleur_, chap. vii. A few examples will be of greater value than any opinions I could cite. They may be found of all sorts—pleasure in physical pain, and pleasure in moral pain. Certain patients find intense enjoyment in irritating their sores. Mantegazza[43] says: “I knew an old man who acknowledged to me that he found an extraordinary pleasure, and one which seemed to him equal to any other, in scratching the inflamed surfaces surrounding a senile sore in his leg from which he had suffered for some years.” Footnote 43: Mantegazza, _Fisiologia del piacere_, p. 26.