Albert Einstein was a theoretical physicist, one of the founders of modern theoretical physics. Einstein was the author of more than 300 scientific papers on physics, as well as about 150 books and articles on the history and philosophy of science, journalism and others. He has developed several important physical theories. Albert Einstein said he believed in the "pantheistic" God of Baruch Spinoza, but not in a personal god, a belief he criticized. He also considered himself that he was an agnostic, while dividing himself from the label atheist, preferring, he said, "an attitude of humility corresponding to the weakness of our intellectual understanding of nature and of our own being".