According to the degree, on the other hand, it will be the more powerful the more _individualised_ it is--that is to say, the more the loved individual, by virtue of all her qualities, is exclusively fit to satisfy the lover's desire and needs determined by her own individuality. If we investigate further we shall understand more clearly what this involves. All amorous feeling immediately and essentially concentrates itself on health, strength, and beauty, and consequently on youth; because the will above all wishes to exhibit the specific character of the human species as the basis of all individuality. The same applies pretty well to everyday courtship (Ἀφροδιτη πανδημος). With this are bound up more special requirements, which we will consider individually later on, and with which, if there is any prospect of gratification, there is an increase of passion. Intense love, however, springs from a fitness of both individualities for each other; so that the will, that is to say the father's character and the mother's intellect combined, exactly complete that individual for which the will to live in general (which exhibits itself in the whole species) has a longing--a longing proportionate to this its greatness, and therefore surpassing the measure of a mortal heart; its motives being in a like manner beyond the sphere of the individual intellect. This, then, is the soul of a really great passion. The more perfectly two individuals are fitted for each other in the various respects which we shall consider further on, the stronger will be their passion for each other. As there are not two individuals exactly alike, a particular kind of woman must perfectly correspond with a particular kind of man--always in view of the child that is to be born. Real, passionate love is as rare as the meeting of two people exactly fitted for each other. By the way, it is because there is a possibility of real passionate love in us all that we understand why poets have depicted it in their works. Because the kernel of passionate love turns on the anticipation of the child to be born and its nature, it is quite possible for friendship, without any admixture of sexual love, to exist between two young, good-looking people of different sex, if there is perfect fitness of temperament and intellectual capacity. In fact, a certain aversion for each other may exist also. The reason of this is that a child begotten by them would physically or mentally have discordant qualities. In short, the child's existence and nature would not be in harmony with the purposes of the will to live as it presents itself in the species. In an opposite case, where there is no fitness of disposition, character, and mental capacity, whereby aversion, nay, even enmity for each other exists, it is possible for love to spring up. Love of this kind makes them blind to everything; and if it leads to marriage it is a very unhappy one.