(_a._) The elements are homogeneous or convergent. If they are numerous, since they all tend in the same direction, the resultant emotion will be of great intensity. We have found one example of this in sexual love, an aggregate compound (according to Herbert Spencer’s analysis) of physical attraction, æsthetic impressions, sympathy, tenderness, admiration, self-love, love of approbation, love of possession, and desire of liberty. (_b._) The elements are heterogeneous or divergent. As an example I take jealousy, which many authorities consider primary, perhaps because it is manifested by animals and infants, which simply proves that it is precocious,—quite a different thing. A contemporary writer tries to define it by saying: “It is a morbid fear passing from inert stupidity to active or passive rage.” I greatly prefer Descartes’ definition: “Jealousy is a kind of fear related to the desire we have of keeping some possession” (_Passions_, art. 167). This passion deserves a monograph to itself, and one will certainly be written when this style of work comes to be applied more frequently to the psychology of the emotions. Our task at present is not to study its gradations, from mild cases up to madness and homicide, but to inquire into its composition. There is, firstly, the representation of some good, possessed or denied—a pleasurable element acting by way of excitement and attraction; and, secondly, the idea of dispossession or privation (_e.g._, of the lover with regard to his mistress, of the rejected candidate against his fortunate rival, and in general, of any who fail against all who succeed), an element of vexation which acts depressively; and, thirdly, the idea of the real or imaginary cause of this dispossession or privation, awakening, in various degrees, the destructive tendency (anger, hatred, etc.). In the passive or inert forms of jealousy this last element is very slight. This emotion is, therefore, a binary compound. We might further mention the religious sentiment (a binary compound), the feeling of respect, composed of sympathy and a slight degree of fear, and the moral sentiment, which we are about to analyse in the next chapter. I must remark that these derivative emotions, by reason of their complexity, ought logically to show as many shades of variety as they have constituent elements. In sexual love, where analysis discovers at least ten tendencies, whether primary or not, the predominance of one or more among these changes the aspect of the emotion according to times and individuals. The instability of the passions, of which we hear so much, is partly caused by their composite character.