Hitherto I have only taken account of the _absolute_ considerations, _i.e._, those which hold good for every one: I come now to the _relative_ considerations, which are individual, because in their case what is looked to is the rectification of the type of the species, which is already defectively presented, the correction of the divergences from it which the chooser’s own person already bears in itself, and thus the return to the pure presentation of the type. Here, then, each one loves what he lacks. Starting from the individual constitution, and directed to the individual constitution, the choice which rests upon such relative considerations is much more definite, decided, and exclusive than that which proceeds merely from the absolute considerations; therefore the source of really passionate love will lie, as a rule, in these relative considerations, and only that of the ordinary and slighter inclination in the absolute considerations. Accordingly it is not generally precisely correct and perfect beauties that kindle great passions. For such a truly passionate inclination to arise something is required which can only be expressed by a chemical metaphor: two persons must neutralise each other, like acid and alkali, to a neutral salt. The essential conditions demanded for this are the following. First: all sex is one‐sided. This one‐sidedness is more distinctly expressed in one individual than in another; therefore in every individual it can be better supplemented and neutralised by one than by another individual of the opposite sex, for each one requires a one‐ sidedness which is the opposite of his own to complete the type of humanity in the new individual that is to be produced, the constitution of which is always the goal towards which all tends. Physiologists know that manhood and womanhood admit of innumerable degrees, through which the former sinks to the repulsive gynander and hypospadæus, and the latter rises to the graceful androgyne; from both sides complete hermaphrodism can be reached, at which point stand those individuals who, holding the exact mean between the two sexes, can be attributed to neither, and consequently are unfit to propagate the species. Accordingly, the neutralisation of two individualities by each other, of which we are speaking, demands that the definite degree of _his_ manhood shall exactly correspond to the definite degree of _her_ womanhood; so that the one‐ sidedness of each exactly annuls that of the other. Accordingly, the most manly man will seek the most womanly woman, and _vice versâ_, and in the same way every individual will seek another corresponding to him or her in degree of sex. Now how far the required relation exists between two individuals is instinctively felt by them, and, together with the other relative considerations, lies at the foundation of the higher degrees of love. While, therefore, the lovers speak pathetically of the harmony of