For this reason, among others, friends are generally of the same sex, for when men and women agree, it is only in their conclusions; their reasons are always different. So that while intellectual harmony between men and women is easily possible, its delightful and magic quality lies precisely in the fact that it does not arise from mutual understanding, but is a conspiracy of alien essences and a kissing, as it were, in the dark. As man’s body differs from woman’s in sex and strength, so his mind differs from hers in quality and function: they can co-operate but can never fuse. The human race, in its intellectual life, is organised like the bees: the masculine soul is a worker, sexually atrophied, and essentially dedicated to impersonal and universal arts; the feminine is a queen, infinitely fertile, omnipresent in its brooding industry, but passive and abounding in intuitions without method and passions without justice. Friendship with a woman is therefore apt to be more or less than friendship: less, because there is no intellectual parity; more, because (even when the relation remains wholly dispassionate, as in respect to old ladies) there is something mysterious and oracular about a woman’s mind which inspires a certain instinctive deference and puts it out of the question to judge what she says by masculine standards. She has a kind of sibylline intuition and the right to be irrationally _à propos_. There is a gallantry of the mind which pervades all conversation with a lady, as there is a natural courtesy toward children and mystics; but such a habit of respectful concession, marking as it does an intellectual alienation as profound as that which separates us from the dumb animals, is radically incompatible with friendship. [Sidenote: and in age.] Friends, moreover, should have been young together. Much difference in age defeats equality and forbids frankness on many a fundamental subject; it confronts two minds of unlike focus: one near-sighted and without perspective, the other seeing only the background of present things. While comparisons in these respects may be interesting and borrowings sometimes possible, lending the older mind life and the younger mind wisdom, such intercourse has hardly the value of spontaneous sympathy, in which the spark of mutual intelligence flies, as it should, almost without words. Contagion is the only source of valid mind-reading: you must imitate to understand, and where the plasticity of two minds is not similar their mutual interpretations are necessarily false. They idealise in their friends whatever they do not invent or ignore, and the friendship which should have lived on energies conspiring spontaneously together dies into conscious appreciation. [Sidenote: Constituents of friendship.]