What is Mathematics&

What Is Mathematics? is a mathematics book written by Richard Courant and Herbert Robbins, published in England by Oxford University Press. It is an introduction to mathematics, intended both for the mathematics student and for the general public.

First published in 1941, it discusses number theory, geometry, topology and calculus. A second edition was published in 1996 with an additional chapter on recent progress in mathematics, written by Ian Stewart.

But according to R. Hersh "They never answered their question; or rather,they answered it by showing what mathematics is, not by telling what it is." So he wrote a book "What mathematics Really Is?" where he "offers a radically different, unconventional answer to that question".