 Hook studied philosophy as an undergraduate at the City College of New York in the early 1920s, where he was influenced by Morris Raphael Cohen. He then attended Columbia University, where he earned a PhD under the supervision of John Dewey. As the background for the development of Hook’s thought, the philosophical and intellectual discussion of this period was dominated by the reigning power of Deweyan pragmatism even as it also showed the emerging signs of the coming influence of Marxism. One illustration of the significance of Dewey for Hook’s intellectual development can be found in the fact that the completion of Dewey’s attempt to produce a naturalist metaphysics, Experience and Nature, took place in the mid-twenties and Sidney Hook’s doctoral dissertation, The Metaphysics of Pragmatism, was defended in 1927.