Man is unique not because he does science, and he is unique not because he does art, but because science and art equally are expressions of his marvellous plasticity of mind.

The new theory, of course, always subsumes more effects than the old. But the remarkable thing is that when it is discovered, it also wholly changes our conception of how the world works.

Now if Newton had been a very plain, very dull, very matter-of-fact man, all that would be easily explicable. But I must make you see that he was not. He was really a most extraordinary, wild character. He practised alchemy. In secret, he wrote immense tomes about the Book of Revelation. He was convinced that the law of inverse squares was really already to be found in Pythagoras. And for such a man, who in private was full of these wild metaphysical and mystical speculations, to hold this public face and say, ‘I make no hypotheses’ – that is an extraordinary expression of his secret character. William Wordsworth in The Prelude has a vivid phrase, Newton, with his prism and silent face, which sees and says it exactly. Well,