 Gödel’s early years at the Institute were notable for his close friendship with his daily walking partner Albert Einstein, as well as for his turn to philosophy of mathematics, a field on which Gödel began to concentrate almost exclusively from about 1943. The initial period of his subsequent lifelong involvement with philosophy was a fruitful one (in terms of publications): in 1944 he published his first philosophical paper, entitled “On Russell’s Mathematical Logic” (Gödel 1944), and in 1947 he published his second, entitled “What is Cantor’s Continuum Hypothesis?” (Gödel 1947). In 1949 he published his third, entitled “A Remark on the Relationship between Relativity Theory and Idealistic Philosophy.” (Gödel 1949a). The latter paper coincided with results on rotating universes in relativity he had obtained in 1949, which were first published in an article entitled: “An Example of a New Type of Cosmological Solutions of Einstein’s Field Equations of Gravitation.” (Gödel 1949).