In this mammoth and encyclopaedic survey of sexual knowledge, first published in German in 1906, the physician Iwan Bloch explores topics ranging from spiritual love to wild love, traditional marriage to foot fetish, erotic painting to morning erection. A quick glance at the subject index at the back of the book gives a taste for the breadth of topics covered.

Sex is seen as much as a cultural and sociological phenomenon as a medical one. Applying this theory Bloch includes a chapter on pornographic literature and art, and another on free love that draws on Goethe, Shelley and the Swedish feminist Ellen Key. For Bloch, sexual love has the power to bring together the lower animal and the higher spiritual parts of human nature, and he is optimistic about the future of this process:

Love regarded … in its inner nature, as a sexual impulse most perfectly and completely infused with a spiritual content … will stand forth ever purer and more promotive of happiness, like a mirror of marvellous clearness, wherein is reflected a peculiar and accurate picture of the successive epochs of civilization.

A book titled The Sexual Life of Our Time was always going to cause a stir in Edwardian England. The 1909 translation featured here begins with a note from the publishers that the sale of the book shall be “limited to members of the legal and medical professions.” (One wonders how many early readers asked a lawyer or doctor friend to pass them a copy.) The attempt to control the readership must be in part down to Bloch’s fearless critique of conventional morality. He reserves his most stinging words for the banning of sex outside of marriage, a convention which he calls "the true cancer of our sexual life, the sole cause of the increasing diffusion of prostitution, of wild sexual promiscuity, and of venereal diseases".

As may be inferred by now, Bloch is a very big advocate of free love, which to him means “sexual union based upon intimate love, personal harmony, and spiritual affinity, entered on by the free resolve of both parties.” As for what kind of sex free lovers should embark on, Bloch is pretty open-minded. Like Freud he believes that supposedly deviant sexual inclinations and behaviours are actually pretty common, and seldom pathological. A crucial example is homosexuality, which Bloch points out “occurs in perfectly healthy individuals quite independently of degeneration and of civilization; and is diffused throughout the whole world.” This was a brave statement to make in an era when the persecution of homosexuals was normal practice.

Not much has been written about Bloch in English but we do know that he was trained as a dermatologist and based in Berlin. The range of literary references in The Sexual Life makes it plain that his radical turn of mind owes a lot to many hours spent in the Royal Library of Berlin. Under the pseudonym Eugène Dühren, Bloch also wrote an 1899 biography of the Marquis de Sade and was the first to publish Sade’s hugely controversial and often banned 120 Days of Sodom (1904), a book described by Sade himself as “the most impure tale ever written since the world began”.

Bloch’s literary endeavours did not impede his scientific output. Along with some other Berlin-based doctors, he formed the first ever medical society for sexology research, and in 1914 he began publishing the Journal of Sexology, which would collect and publish many important studies over the following two decades. He also published three volumes of the Handbook of Sexology in its Entirety Presented in Separate Studies (1912–25) but that ambitious project was nixed by Bloch’s untimely death at the age of 50.