A lens grinder's table

Spinoza's room in Amsterdam smells of glass dust and tobacco, and he works as he talks, shaping a lens on a wooden lathe. Leibniz has come to see the man whose Theological-Political Treatise is being passed around in secret; Newton, then twenty-two and unknown, is on a visit to the Dutch Republic.

The conversation turns on substance and on method. Spinoza holds that there is only one substance and that mind and body are its two aspects; Newton, who is already thinking about motion and force, finds the metaphysics beside the point and wants to know how the lens is ground. Leibniz takes notes and asks about the infinite. They eat soused herring, oysters in ale, coarse bread, and gingerbread, and the two mathematicians leave together, arguing.