[Thomas Hobbes (1588–1679)] was forty years old before he looked on geometry, which happened accidentally. Being in a gentleman's library, Euclid's Elements lay open and 'twas the 47 El libri I. He read the proposition. By God, said he (he would now and then swear an emphatical oath by way of emphasis) this is impossible! So he reads the demonstration of it which referred him back to such [another] proposition; which proposition he read. That referred him back to another, which he also read. And so on that at last he was demonstratively convinced of that truth. This made him in love with geometry.