Nicolas Rashevsky (November 9, 1899 – January 16, 1972) was an American theoretical physicist who was one of the pioneers of mathematical biology, and is also considered the father of mathematical biophysics and theoretical biology. Academic career He studied theoretical physics at the St. Vladimir Imperial University of Kiev. He left Ukraine after the October Revolution, emigrating first to Turkey, then to Poland, France, and finally to the US in 1924. In USA he worked at first for the Westinghouse Research Labs in Pittsburgh where he focused on the theoretical physics modeling of the cell division and the mathematics of cell fission. He was awarded a Rockefeller Fellowship in 1934 and went to the University of Chicago to take up the appointment of assistant professor in the Department of Physiology. In 1938, inspired by reading On Growth and Form (1917) by D'Arcy Wentworth Thompson, he made his first major contribution by publishing his first book on Mathematical Biophysics, and then in 1939 he also founded the first mathematical biology international journal entitled The Bulletin of Mathematical Biophysics (BMB); these two essential contributions founded the field of mathematical biology, with the BMB journal serving as the focus of contributing mathematical biologists over the last 70 years. Major scientific contributions In 1938 he published one of the first books on mathematical biology and mathematical biophysics entitled: "Mathematical Biophysics: Physico-Mathematical Foundations of Biology." This fundamental book was eventually published in three revised editions, the last revision appearing in two volumes in 1960. It was followed in 1940 by "Advances and applications of mathematical biology.", and in 1947 by "Mathematical theory of human relations", an approach to a mathematical model of society. In the same year he established the World' s first PhD program in Mathematical Biology at the University of Chicago. In the early 1930s, Rashevsky developed the first model of neural networks. This was paraphrased in a Boolean context by his student Walter Pitts together with Warren McCulloch, in an article published in Rashevsky's Bulletin of Mathematical Biophysics in 1943. The Pitts-McCulloch article subsequently became extremely influential for research on artificial intelligence and artificial neural networks. His later efforts focused on the topology of biological systems, the formulation of fundamental principles in biology, relational biology, set theory and propositional logic formulation of the hierarchical organization of organisms and human societies. In the second half of the 1960s, he introduced the concept of