To return, however, to the more scientific aspects of the question, the polarity of sex displays itself as conspicuously as that of the magnet in the fundamental law of repulsion of like for like, and attraction of like for unlike. In each case there must be an identity of essence developing itself in opposite directions. Thus, atoms attract or repel atoms, but not molecules; for if they seem to do so, it is only in cases in which the molecule contains some atom whose atomicity or polar power has not been fully satisfied. So currents of air or water do not affect electric currents. But given the identity of substance, its differentiation takes place under an ever-increasing progression of polarity of affinities and repulsions. A German naturalist, Brahm, discussing the question why birds sing, says, ‘the male finds in the female those desirable and attractive qualities which are wanting in himself. He seeks the opposite to himself with the force of a chemical element.’ This is equally true of the male and female of the human species. A masculine woman and effeminate man are equally unattractive, and if the qualities are pushed to an extreme extent, the individuals become monstrosities, and, instead of attracting, excite vehement disgust and repulsion. This, which is true physically, is equally true of moral and intellectual characteristics. Each seeks, in the happy marriage or perfect ideal union, the qualities which are most deficient in themselves: the woman, strength, active courage, and the harder qualities; the man, gentleness, amiability, and the softer virtues. In each individual, as in each union of individuals, harmony and perfection depend on the due balance of the opposite qualities, and the ‘falsehood of extremes’ leads up to chaos and insanity. The man in whom strength and hardihood are not tempered by gentleness and affection becomes brutal and tyrannical; while the woman who has no strength of character becomes silly and frivolous. Marriage, however, involves the highest ideal, for the well-assorted union of the two in one gives a more complete harmony and reconciliation of opposites than can be attained by the single individual, who must always remain more or less within the sphere of the polarity of his or her respective sex. But here also the same law of polarity operates, for as happy marriage affords the highest ideal, so do unhappy and ill-assorted unions involve the greatest misery and most complete shipwreck of life. Especially to the woman, for the man has other pursuits and occupations, and can to a great extent withdraw himself from domestic troubles; while the woman has no defence against the coarseness, selfishness, and vulgarity of the partner to whom she is tied, and who may make her life a perpetual purgatory, and drag all her finer intellectual and moral nature down to a lower level. Fortunately extreme cases are rare, and, though the ideal of a perfect