Sexual Mystics and the Brides of Christ present the darker aspect of metaphysical love.  All the latter, including even Catherine of Siena (a clever politician who kept up a correspondence with the leading statesmen of her time), Marie of Oignies, and St. Teresa, are stigmatised as victims of hysteria and consigned to the domain of pathology.

While the first stage was characterised by the reign of unbridled sexual instinct, the second by the conflict between spiritual and sensual love, the third stage represents our modern conception, the blending of spiritual and sensual love, which is “not the differentiated sexual instinct, but a force embracing the psycho-physical entity of the beloved being without any consciousness of sexual desire.”  It shares with the purely metaphysical love the lover’s longing to raise his mistress above him and glorify her without any ulterior object and desire.  “In this stage there is no tyranny of man over woman, as in the sexual stage; no subjection of man to woman, as in the woman-worship of the Middle Ages; but complete equality of the sexes, a mutual give and take.  If sexuality is infinite as matter, spiritual love eternal as the metaphysical ideal, then the synthesis is human and personal.”  The apotheosis of this perfect love Lucka finds in the Liebestod (the death of the lovers in the ecstasy of love), in Wagner’s Tristan und Isolde.

An interesting chapter on erotic aberrations, the demoniacal and the obscene, completes the third part of the book.

There may be much in Lucka’s theories which will rouse the scepticism of the monists; some of his deductions may appear to his readers a little strained, but no thinking man or woman can read his brilliant Conclusion without denying him the tribute of sincere admiration.  In this last chapter he applies Haeckel’s biogenetic law to the domain of the spirit.  As the human embryo passes through the principal stages of the development of the individual from lower forms of life, so the growing male must pass through the stages of psychical development through which the race has passed.  The gynecocratic government of prehistoric time is revived in the nursery, where the mother rules supreme and the sisters dominate.  The normal, healthy school-boy, preferring the company of his school-fellows to all others, shunning his mother and sisters, ashamed of his female relatives, is the modern individual representative of those early leagues and unions of young men who opposed matriarchy and finally brought about its overthrow and the establishment of male government.  The promiscuous sexuality characteristic of adolescence reproduces the first, merely sexual, stage of the erotic life of the race in the life of the individual.  As a rule this phase is followed by a period of woman-worship; love has conquered the sexual instinct and the latter is felt as base and degrading.  Atavism is not so much the persistence of the earlier, as the absence of the later stages of psychical development.