This article examines the intellectual and institutional factors that contributed to the col- laboration of neuropsychiatrist Warren McCulloch and mathematician Walter Pitts on the logic of neural networks, which culminated in their 1943 publication, “A Logical Calculus of the Ideas Immanent in Nervous Activity.” Historians and scientists alike often refer to the McCulloch–Pitts paper as a landmark event in the history of cybernetics, and fundamental to the development of cognitive science and artificial intelligence. This article seeks to bring some historical context to the McCulloch–Pitts collaboration itself, namely, their intellectual and scientific orientations and backgrounds, the key concepts that contributed to their paper, and the institutional context in which their collaboration was made. Al- though they were almost a generation apart and had dissimilar scientific backgrounds, McCulloch and Pitts had similar intellectual concerns, simultaneously motivated by issues in philosophy, neurology, and mathematics. This article demonstrates how these issues converged and found resonance in their model of neural networks. By examining the intellectual backgrounds of McCulloch and Pitts as individuals, it will be shown that besides being an important event in the history of cybernetics proper, the McCulloch– Pitts collaboration was an important result of early twentieth-century efforts to apply mathematics to neurological phenomena.

An instance of fruitful cross-disciplinary contacts is examined in detail. The ideas involved include (1) the double-bind hypothesis for schizophrenia, (2) the critique of game theory from the viewpoint of anthropology and psychiatry, and (3) the application of concepts of communication theory and theory of logical types to an interpretation of psychoanalytic practice. The protagonists of the interchange are Gregory Bateson and the two mathematicians Norbert Wiener and John von Neuman; the date, March 1946. This interchange and its sequels are described. While the interchanges between Bateson and Wiener were fruitful, those between Bateson and von Neumann were much less so. The latter two held conflicting premises concerning what is significant in science; Bateson’s and Wiener’s were compatible. In 1946, Wiener suggested that information and communication might be appropriate central concepts for psychoanalytic theory – a vague general idea which Bateson (with Ruesch) related to contemporary clinical practice. For Bateson, Wiener, and von Neumann, the cross-disciplinary interactions foreshadowed a shift in activities and new roles in society, to which the post-World War II period was conducive. Von Neumann became a high-level government advisor; Wiener, an interpreter of science and technology for the general public; and Bateson, a counter-culture figure.