Horace Walpole turns to the letters and argues that: Walpole's numerous letters are often used as a historical resource. In one, dating from 28 January 1754, he coined the word serendipity which he said was derived from a "silly fairy tale" he had read, "The Three Princes of Serendip". The oft-quoted epigram, "This world is a comedy to those that think, a tragedy to those that feel", is from a letter of Walpole's to Anne, Countess of Ossory, on 16 August 1776. The original, fuller version appeared in a letter to Sir Horace Mann on 31 December 1769: "I have often said,
Baron Walpole for Robert Walpole, son of Sir Robert Walpole in honour of and during the lifetime of his father, the "de facto" first Prime Minister of Great Britain, with special remainder, failing male issue, to his brothers Edward Walpole and Horace Walpole, in default of this then to the heirs male of his father, and in default of this then to the heirs male of his grandfather Sir Thomas Walpole. On Sir Robert Walpole's retirement from the House of Commons in 1742, he received the titles, Baron Walpole of Houghton in the County of Norfolk, Viscount Walpole and Earl of Orford,