Denis Diderot holding marble dust above a bowl, with a sculpted bust behind him

How a marble statue finds its way into a pea

Denis Diderot (1713–1784), the French writer and co-editor of the Encyclopédie, gives his friend d’Alembert a disarmingly simple question to ask. What difference does Diderot see between a human being and a statue, between marble and flesh? Anyone who has touched a statue could offer an answer. The stone stays cool under the fingers, while a hand might return their pressure. Diderot’s reply takes a detour through a garden.

What could become of a statue?

Very little. One makes marble out of flesh, and flesh out of marble.

– Denis Diderot, Entretien entre d’Alembert et Diderot, 1875, p. 105.[1]

The exchange comes at the opening of the dialogue. D’Alembert has raised an objection to the idea that sensitivity belongs to matter as such. In that case even a stone must be capable of feeling. Diderot first asks him to consider the position of a sculptor who cuts or crushes a stone and never hears it cry. Then he changes the experiment. Imagine taking a marble figure by the sculptor Falconet, pounding it into fine powder, mixing the powder with soil, watering it and giving it all the time it needs.

An answer growing in a garden bed

D’Alembert anticipates a snag. Surely his friend has no intention of eating the soil? Diderot has peas, beans and cabbages in mind. They grow in the prepared ground, a person eats them, and something from the garden enters a human body. The startling exchange of the words marble and flesh at the beginning now has a course in time that a listener can follow. A pleasure of the scene lies in who supplies the last insight. D’Alembert himself guesses that a plant could be the missing link. He leaves the truth of the larger claim open. The journey from the studio to the garden bed and on to the dinner table has given him room to think.