Russian-born American sociologist and political activist (1889-1968) who is best known for his contributions to the social cycle theory. A leader among the Democrats leading up to the Russian revolution, he escaped from the Soviet Union in 1922 and emigrated to the United States, accepting a position at Harvard University and founding its Department of Sociology. Five TLSs, signed “P. A. Sorokin” or “P. Sorokin,” six total pages, 5.5 x 8.5 and 8.5 x 11, dated between February 1960 and April 1961. Each letter is addressed to Miss Frances Paelian and written on Harvard University letterhead. The earliest letter, February 5, 1960: “I thank you for your ‘Modern Science Discovers Love.’ Your popularization of some recent scientific works in this field is written well. Your personal illustrations are well designed…I expect to be in California from March 1st to March 18, giving lectures and conferences at a few California colleges and universities,” with Sorokin adding a handwritten postscript: “Perhaps it is advisable also to send a copy of your publications to Mr. M. M. Pattilo, Director of the Lilly Endowment.” A letter from February 26, 1960, in part: “Yesterday I received a book by a Swedish psychologist Bjorn Sjovall, entitled: Hojdpsyologi (Height-Psychology, in contrast to the Freudian ‘depth-psychology’ which Sjovall, like myself, finds perfectly ‘shallow-psychology’). In this book Dr. Sjovall, like yourself, honors me as the founder and leader of this new ‘Height-Psychology.’” Another, dated July 5, 1960, in part: “Returning from California I had a time to write an article on ‘American Sex Morality’ for Christianity Today. The article possibly is already published in the issue of July 4th. Then I wrote a substantial paper: ‘Variations on Spencerian Theory of Militant and Industrial Society.’” In overall fine condition.