Philip Stanhope, Earl of Chesterfield, was at one time Ambassador to the Hague, negotiated the second Treaty of Vienna, was a founding governor of London’s Foundling Hospital, Lord-Lieutenant of Ireland, and Secretary of State. Having no legitimate children, his heir was his third cousin (another Philip) whom he adopted. Although known as a hard, calculating man, he is most well known for his letters to his natural son (i.e., illegitimate son) (also called Philip). When Philip died in 1768, the letters are addressed to his grandchildren (Philip’s two sons, Charles, and, yes, Philip!)....