When walking in London, Thomas Hobbes, the 17th-century philosopher who famously held that all our actions are self-interested, gave a coin to a beggar. His companion, eager to catch the great man out, told Hobbes that he had just refuted his own theory. Not so, Hobbes responded: he gave the money because it pleased him to see the poor man happy. Hobbes thus avoided the refutation of his theory by widening the notion of self-interest so that it is compatible with a great deal of generosity and compassion. That reminds us that there is both a broad and a narrow sense of self-interest.
