That expectation of the professional, 24-7 politician wasn’t there in the late nineteenth and early twentieth centuries. The last proper intellectual Prime Minister was Arthur Balfour, in Downing Street from 1902 until 1905. Balfour may not have been a great Prime Minister, but he was a serious philosopher. His series of Gifford Lectures in 1914 at Glasgow University, on “Theism and Humanism”, were published as a book in 1915. C. S. Lewis said it was one of the ten books that influenced him most.