Santayana's familial situation was unusual. Born Jorge Agustín Nicolás Ruiz de Santayana, he spent his childhood in Ávila. His father was a diplomat, painter, and minor intellectual. Jorge was the only child of his mother's second marriage. She was the widow of a Sturgis from Boston, by whom she had three children, Santayana's cherished half siblings. In order to marry Jorge's father, she left those children in Boston in the care of others and moved to Spain, where she resided until returning to her Boston children in 1869.

Jorge and his father followed her in 1872 but his father, not finding Boston to his liking, soon returned to Ávila for good, so that from age six his parents almost always lived apart. Around this time, he americanized his name to George, the English variant of Jorge. He did not see his father again until summer vacations while at Harvard.

He attended Boston Latin School and Harvard University, studying under William James and Josiah Royce, whose colleague he subsequently became. After graduating from Harvard in 1886, he studied for two years in Berlin, then returned to Harvard to write a thesis on Rudolf Hermann Lotze and teach philosophy, thus becoming part of the Golden Age of Harvard philosophy. Some of his Harvard students became famous in their own right, including T. S. Eliot, Wallace Stevens, Walter Lippmann, and Harry Austryn Wolfson.

In 1912, an inheritance from his mother allowed him to retire from Harvard and spend the rest of his life in Europe. After some years in Paris and Oxford, he began to winter in Rome starting in 1920, eventually living there year-round until his death in 1952. During his 40 years in Europe, he wrote 19 books and declined several prestigious academic positions.

Most of his friends and correspondents were Americans, including his valuable assistant and eventual literary executor, Daniel Cory. The aged Santayana was comfortable, in part because The Last Puritan sold well. In turn, he assisted financially a number of writers including Bertrand Russell, with whom he was in fundamental disagreement, philosophically and politically. Santayana never married. For a biography, see McCormick (1987).

The Philosopher
Santayana's main philosophical work consists of his first book, The Sense of Beauty, perhaps the first major work on aesthetics written in the USA, the five volume The Life of Reason, the high point of his Harvard career, and the four volume The Realms of Being. Although Santayana is not deemed a canonical pragmatist in the mold of James, Charles Peirce, Royce, or John Dewey, The Life of Reason arguably forms the first extended treatment of pragmatism. Like many classical pragmatists, and because he was also well-versed in evolutionary theory, Santayana was committed to a naturalist metaphysics, in which human cognition, cultural practices, and institutions evolved so as to harmonize with their environment.

Their value was the extent to which they facilitated human happiness. He was an early adherent of epiphenomenalism, but also admired the classical materialism of Democritus and Lucretius. He held Spinoza's writings in high regard, without subscribing to Spinoza's rationalism or pantheism. Although an atheist, he described himself as an "aesthetic Catholic", and spent the last decade of his life in a Roman convent, attended to by nuns.

The Man of Letters
Santayana's one novel, The Last Puritan, is perhaps the greatest Bildungsroman in American letters. Among American autobiographies, his Persons and Places deserves to be put on the same plane as The Education of Henry Adams. These masterworks of his also contain many of his tarter opinions and bon mots. He wrote books and essays on a wide range of subjects, including philosophy of a less technical sort, literary criticism, the history of ideas, politics, human nature, morals, the subtle influence of religion on culture and social psychology, all with considerable wit and humor, and pervaded with a good feel for the subtlety and richness of the English language. While his writings on technical philosophy can be difficult, his other writings are far more readable, and all of his books contain quotable passages. He wrote poems and a few plays, and left an ample correspondence, much of it published only since 2000.

In his many value judgements and prejudices, many of which do not sit well with present-day fashion, Santayana was aristocratic and elitist, a curious blend of Mediterranean conservative (similar to Paul Valery), cultivated American, Olympian aloofness, and ironic detachment. Russell Kirk discussed Santayana in his The Conservative Mind from Edmund Burke to T. S. Eliot.

Among those writing about American culture and character from a foreign point of view, Alexis de Tocqueville is perhaps his only peer. Among American writers combining philosophy and letters, Ralph Waldo Emerson is his only rival. Even though he declined American citizenship and resided in fascist Italy for two decades, he is a major American writer. Even so, the Hispanic world is gradually recognizing him as one of its own, with Spanish translations of his work proceeding apace.