“... The passion which unites the sexes ... is habitually spoken of as though it were a simple feeling; whereas it is the most compound, and therefore the most powerful, of all the feelings. Added to the purely physical elements of it are first to be noticed those highly complex impressions produced by personal beauty, around which are aggregated a variety of pleasurable ideas, not in themselves amatory, but which have an organised relation to the amatory feeling. With this there is united the complex sentiment which we term affection—a sentiment which, as it can exist between those of the same sex, must be regarded as an independent sentiment, but one which is here greatly exalted. Then there is the sentiment of admiration, respect, or reverence; in itself one of considerable power, and which, in this relation, becomes in a high degree active. Then comes next the feeling called love of approbation. To be preferred above all the world, and that by one admired beyond all others, is to have the love of approbation gratified in a degree passing every previous experience, especially as there is that indirect gratification of it which results from the preference being witnessed by unconcerned persons. Further, the allied emotion of self-esteem comes into play. To have succeeded in gaining such attachment from, and sway over, another, is a proof of power which cannot fail agreeably to excite the _amour propre_. Yet again, the proprietary feeling has its share in the general activity: there is the pleasure of possession; the two belong to each other. Once more, the relation allows of an extended liberty of action. Towards other persons a restrained behaviour is requisite. Round each there is a subtle boundary that may not be crossed—an individuality on which none may trespass. But in this case the barriers are thrown down, and thus the love of unrestrained activity is gratified. Finally, there is an exaltation of the sympathies. Egoistic pleasures of all kinds are doubled by another’s sympathetic participation, and the pleasures of another are added to the egoistic pleasures. Thus, round the physical feeling forming the nucleus of the whole, are gathered the feelings produced by personal beauty; that constituting simple attachment, those of reverence, of love of approbation, of self-esteem, of property, of love of freedom, of sympathy. These, all greatly exalted, and severally tending to reflect their excitements on one another, unite to form the mental state we call love. And as each of them is itself comprehensive of multitudinous states of consciousness, we may say that this passion fuses into one immense aggregate most of the elementary excitations of which we are capable; and that hence results its irresistible power.”[159] ----- Footnote 159: _Principles of Psychology_, vol. i., § 215. -----