Ivan Orlov

Ivan Efimovich Orlov (1886–after 1936) was a Russian philosopher and industrial chemist. He is recognized as a forerunner of relevant and other substructural logics. Born in Galich, Kostroma Oblast, Orlov studied at the Natural Sciences Faculty of Moscow University. His academic career commenced in 1916 with publications on inductive reasoning. Following a hiatus due to political turmoil, he taught at the Communist Academy in the 1920s and held a position at the Chemical Institute. By 1923, Orlov became highly productive, publishing extensively in Soviet journals on the philosophy of mathematics and dialectical logic, a Marxist-influenced field. His work also touched upon probability theory, psychology, music theory, and chemical engineering. Orlov's logical research focused on uncovering the specific "logic" of natural sciences, treating thought laws as formal rules bounded by identity and contradiction. He proposed a "logic of compatibility of propositions" in 1928, analyzing the compatibility of propositions through an implication procedure. He also anticipated the translation of intuitionistic negation systems into S4 modal logic. Orlov's contributions were largely unrecognized for decades due to his publications being primarily in Russian and unknown outside the Soviet Union. His pioneering role in substructural logics only emerged post-World War II. He was critical of set theory, the theory of relativity, and heliobiology. Around 1928, Orlov transitioned from logic and philosophy to industrial chemistry, focusing on bromine and iodine production and translating German chemistry works. The exact date of his death is unknown, but it is estimated to be between 1936 and 1937 in Moscow.