Inasmuch as we have pointed out as the single primæval basis, as the most important elementary phenomenon, of human love, the conjugation of the male sperm cell with the female ovum (dependent probably upon a sensation analogous to that of smell), we denote this particular phenomenon of sexuality as =primary=, and we separate all the other phenomena as =secondary=, as more remote. Wilhelm Bölsche has also expressed this difference by denoting the union of the two reproductive cells as “=fusion-love=,” whilst all that has occurred later, in the course of many thousands of years of evolution, and that has transformed this primary process, by innumerable new influences, stimuli, and perceptions, into the love of modern civilized man, he denotes by the apt name of “=distance-love=.” According to him, “the ultimate act of love in a member of the most highly civilized community assumes the form of a sudden withdrawal from the entire world of surrounding artifacts, of alphabets, posts, telephones, submarine cables, etc.... At this instant the principle of union is once again victorious, as it were, in an ultimate posthumous vision in a vital experience of a portion of primæval Nature, of the primæval world, of an instant’s profoundest self-absorption into the great mystery of the obscure original basis of Nature, to which neither time nor old and new is known, but which is ever renewed in us in its elemental force--the procreative principle. At this instant the loving individual must return home to the heart of the all-mother--it is useless to resist. It must draw from the fountain of youth--must descend like Odin to the Norns, like Faust to the Mothers--=and there all civilization is swallowed up; there cell body must join cell body=, in order in the ardent embrace to reduce to a minimum the distance which usually sunders such large bodies. Indeed, in reality the sexual act goes further and deeper than this reduction of separation to a minimum. Within the body of one of the partners of the sexual act the ovum and the spermatozoon undergo an ultimate =perfect fusion= of soul and body, in comparison with which even the closest approximation of the great halves of the love partnership is no more than a mere mechanical apposition. The ultimate aim of the loving union is attained only in the coalescence of ovum and spermatozoon.” To express the matter briefly, fusion-love fulfils the purpose of the species, while distance-love subserves rather the purpose of the individual. Thus the natural course of the development of love, which in the next chapter we propose to follow further, affords already the proof of the thesis propounded in the introduction regarding the duplicate nature of human love.