It is curious, as we have suggested before, how married folk often quarrel to desperation on the surface, and yet seem to have a deep and permanent hold on each other—returning together again even after separation. It seems in these cases as if they mutually obtained a stimulus from each other, even by their strife, which they could not get elsewhere. _Iræ amantium redintegratio amoris._ The idea, too, that the great and primal object of union is to be sought in _the next generation_ has something unsatisfactory about it. Why not in _this_ generation? Why should the blessedness of mankind always be deferred to posterity? It is not merely, I take it, the _perpetuation_ of the race which is the purpose of love, but the perfection of the race, the completeness and adequacy of its self-expression, which love may make possible to-day just as well as to-morrow. Ellen Key, in that fine book, _Liebe und Ehe_,[32] expresses this well when she says: “Love seeks union, not only in connection with the creation of a new being, but also because two beings _through one another_ may become a new being, and a greater than either could be of itself alone.” The complementary nature of sex-attraction was made much of by that youthful genius Otto Weininger, who in his book, _Sex and Character_,[33] has a chapter on the laws of Sexual Attractions in which, in the true German manner, he not only gives an algebraic formula for the different types of men and women, but a formula also for the force of attraction between any two given individuals—which latter of course becomes infinite when the two individuals are exactly complementary to each other! Dr. Magnus Hirschfeld, in his very interesting work, _Die Transvestiten_,[34] goes even more into detail than does Weininger on the subject of the variations of human type in special regard to sex-characteristics. Sex-characteristics, he explains, may be divided into four groups, of which two are physiological, namely the primary characteristics (the sex organs and adjuncts) and the secondary (the hair, the voice, the breasts, and so forth); and two are psychological or related (like love-sentiment, mental habit, dress, and so forth). Each of the four groups includes about four different elements; so that altogether he tabulates sixteen elements in the human being—each of which may vary independently of the other fifteen, and take on at least three possible forms, either distinctly masculine, distinctly feminine, or intermediate. Calculating up the number of different types which these variations would thus give rise to, he arrives at the figure 43,046,721!—which figure, I think we may say, we need not analyze further, since it is certainly quite large enough for all practical purposes! And really though we may mock a little at these fanciful divisions and dissections of human nature, they do help us to realize the enormous, the astounding number of varieties of which it is susceptible.