### „It is almost as hard to define mathematics as it is to define economics, and one is tempted to fall back on the famous old definition attributed to Jacob Viner, “Economics is what economists do,” and say that mathematics is what mathematicians do. A large part of mathematics deals with the formal relations of quantities or numbers.“

— Kenneth E. Boulding British-American economist 1910 - 1993

1970s, Economics As a Science, 1970, p. 97