Buy a 250-year-old sex manual attributed to Aristotle.

First appearing in the seventeenth century, Aristotle’s Master-Piece was an important way of sharing information about sex and reproduction at a time when such information was carefully guarded out of a sense of propriety. Dozens of print runs were put out well into the nineteenth century. The books were often sold under-the-counter because of laws banning trade in pornographic material.

In 2013, a Scottish auction house sold a copy dating from 1766. Although estimated at £400, the manuscript ultimately collected a whopping £688. The work is not by Aristotle at all, though he did write about reproduction in several of his biological works.