A Mathematician's Apology is a 1940 essay by British mathematician G. H. Hardy which defends the pursuit of mathematics for its own sake. Central to Hardy's "apology" – in the sense of a formal justification or defence – is an argument that mathematics has value independent of its applications. Hardy located this value in what he called the beauty of mathematics and gave some examples of and criteria for mathematical beauty. The book also includes a brief autobiography which gives insight into the mind of a working mathematician.