Montesquieu is widely regarded as one of the founders of many of the social sciences. His broad erudition and deep concentration led to his great work The Spirit of the Laws, published in 1748. Before that he had written other notable works including the Persian Letters, published in 1721. By considering his life and his work in relation to each other, and all his works alongside each other, we can see inside the mind of one of the greatest of modern thinkers. He was the first great global thinker who could base his work on sources from around the world.