I have heard an atheist defined as a man who had no invisible means of support.

A play on words commonly used referring to vagrants or paupers as having "no visible means of support" financially, speaking to the Law Society of Upper Canada, (21 February 1936); published in Canadian Occasions (1940), p. 201. Buchan's source for this definition remains unknown. The witticism was repeated by Harry Emerson Fosdick in his On Being a Real Person (1943), ch. 1, with due acknowledgement to Buchan, and was again used by Archbishop Fulton J. Sheen in Look magazine (December 14, 1955). The credit for this line is therefore often wrongly given to Fosdick or to Sheen. Credit has also been given to the conductor Walter Damrosch (1862-1950).