This fusion of complementaries, then, which is the characteristic of fertilization, takes place between the lovers—not only in respect of their sex-cells, but probably also to a considerable degree in respect of their body-cells. And though with any mortal lovers the complementary nature of the fusion can hardly be so complete as to restore the full glory of the race-life, yet very near to that point it sometimes comes, filling them with mad and immortal-seeming ecstasies, and excusing them indeed for seriously thinking that the wings of their souls have begun to grow! In lesser degree this complementary fusion and exchange is doubtless the explanation (or one explanation) of that very noticeable point—the strange way in which lovers after some years come to resemble each other—in form and feature, in facial expression, tone of voice, carriage of body, handwriting, and all sorts of minute points. * * * * * I suppose at this point it will be necessary to explain that the recognition of love (in all its aspects) as a general condition of human health, does not mean a recommendation of wild indulgence in any and every passion—necessary, because in these cases it seems to be generally assumed that the proposer of a very simple thesis means a very great deal more than he says! It is here that the necessity of education comes in; for hitherto public instruction and discussion in these matters have been so defective that folk have been unable to talk about them except in a hysterical way—hysterical on the one side or the other. The _positive_ value of love, its positive cultivation as a gracious, superb, and necessary part of our lives has hardly (at least in the Anglo-Saxon world) entered into people’s minds. To teach young things to love, and how to love, to actually instruct and encourage them in the art, has seemed something wicked and unspeakable. Says Havelock Ellis:[23] “Whether or not Christianity is to be held responsible, it cannot be doubted that throughout Christendom there has been a lamentable failure to recognize the supreme importance, not only erotically but morally, of the art of love. Even in the great revival of sexual enlightenment now taking place around us there is rarely even the faintest recognition that in sexual enlightenment the one thing essentially necessary is a knowledge of the art of love. For the most part sexual instruction, as at present understood, is purely negative, a mere string of thou-shalt-nots. If that failure were due to the conscious and deliberate recognition that while the art of love must be based on physiological and psychological knowledge, it is far too subtle too complex, too personal, to be formulated in lectures and manuals, it would be reasonable and sound. But it seems to rest entirely on ignorance, indifference, or worse.”