Denis Diderot was born 313 years ago, on 5 October 1713. By day, he worked on the *Encyclopédie*, trying to organise everything humanity knew. He also found time to write *Les Bijoux indiscrets*, in which a magical ring compels women’s most intimate “jewels” to tell the truth. The Enlightenment apparently had a broader range of interests than later school textbooks would have us believe. Diderot understood that human beings are not made of reason alone. We also come with bodies, desires, vanity and secrets — along with an extraordinary talent for arranging all of them neatly behind a set of moral principles. Today, we no longer need a magical ring. We talk voluntarily. Into cameras. Into microphones. In posts. Diderot might only be surprised that we have also managed to find subscribers for it.