Moses Schönfinkel: Combinatory Logic Pioneer | Generated by AI
Moses Schönfinkel (1888–1942) was a Russian logician and mathematician primarily known for his invention of combinatory logic. Born in Ekaterinoslav (now Dnipro, Ukraine), he studied mathematics at Novorossiysk University of Odessa under Samuil Osipovich Shatunovskii.
From 1914 to 1924, Schönfinkel was a member of David Hilbert’s influential group at the University of Göttingen in Germany. It was there, on December 7, 1920, that he delivered a pivotal talk titled “Elemente der Logik” (“Elements of Logic”), outlining the foundational concepts of combinatory logic. This work was later revised by Heinrich Behmann and published in 1924 as “Über die Bausteine der mathematischen Logik” (“On the Building Blocks of Mathematical Logic”).
Schönfinkel’s key contribution was the development of a formal system that avoided the use of bound variables, a significant departure in logic at the time. His system was based on “combinators” (which he called “building blocks”), particularly the S, K, and a universally quantified NAND function (which he called U). He demonstrated that this system, despite its apparent simplicity, had the same power as predicate logic and could be reduced to a minimal set of combinators, notably S and K.
Another crucial idea presented in his 1924 paper was the concept that functions of multiple arguments could be replaced by functions taking a single argument. This technique, later termed “currying” after Haskell Curry who further developed Schönfinkel’s ideas, is fundamental in functional programming and lambda calculus.
Schönfinkel’s known published work consists of just two papers: the 1924 paper on combinatory logic and a 1928 paper on special cases of the decision problem (Entscheidungsproblem), co-authored with Paul Bernays.
After leaving Göttingen, Schönfinkel returned to Moscow. Unfortunately, he reportedly suffered from mental illness by 1927 and spent his later life in poverty, dying in Moscow sometime in 1942. His papers were tragically burned by his neighbors for heating during wartime. Despite his relatively short period of prolific research, Moses Schönfinkel’s invention of combinatory logic laid a foundational stone for the theory of abstract computation and greatly influenced the development of mathematical logic and functional programming.