The method in Paris

Descartes is in Paris to see his Meditations through the press, and has invited the young Blaise Pascal, whose calculating machine he admires, and Galileo, passing through on his way back to Tuscany. He wants to test the method of doubt on two very different minds.

Pascal takes to it at once and immediately pushes it further than Descartes intends, asking why the doubt itself should be exempt. Galileo, trained in observation, finds the whole exercise a detour from the study of nature. They eat a raised pie, syllabub, and spiced wine, and the argument about first principles runs long past the meal.