1930 Half-sister Josephine dies in Ávila, on 15 October, at age 77. The Realm of Matter: Book Second of Realms of Being published in September.

1931 The Genteel Tradition at Bay published at the beginning of the year. In December, Santayana declines offer to become the William James Professor of Philosophy at Harvard.

1932 Santayana attends a philosophical congress commemorating the tercentenary of Spinoza’s birth, held at The Hague on 6–10 September; delivers a lecture on “Ultimate Religion.” Attends a meeting in London to commemorate the tercentenary of John Locke’s birth; on 19 October, delivers an address on “Locke and the Frontiers of Common Sense.”

1933 Some Turns of Thought in Modern Philosophy published.

1935 The Last Puritan: A Memoir in the Form of a Novel published in London in October (published in New York in 1936).

1936 The Last Puritan becomes a Book-of-the-Month Club bestseller.

1937 The Realm of Truth: Book Third of Realms of Being published in London in October (published in New York in 1938).

1938 The first book-length biography published: George Santayana, by George Washburne Howgate.

1939 World War II breaks out in Europe; Santayana, denied a regular long- term visa by Swiss officials, decides to remain in Italy.