Eddington starts by asking: ‘When Lord Rutherford showed us the atomic nucleus, did he find it or did he make it?’ Whichever answer we give, Eddington goes on to say, makes no difference to our admiration for Rutherford himself. But it makes all the difference to our ideas on the structure of the physical universe. To make clear where the modern physicist stands in this respect, Eddington uses a striking comparison. If a sculptor were to point in our presence to a raw block of marble saying that the form of a human head was lying hidden in the block, ‘all our rational instinct would be roused against such an anthropomorphic speculation’. For it is inconceivable to us that nature should have placed such a form inside the block. Roused by our objection, the artist proceeds to verify his theory experimentally – ‘with quite rudimentary apparatus, too: merely using a chisel to separate the form for our inspection, he triumphantly proves his theory.’