Reminiscences of the Vienna Circle and the Mathematical ColloquiumKarl Menger was born in Vienna on January 13, 1902, the only child of two gifted parents. His mother Hermione, nee Andermann (1870 1922), in addition to her musical abilities, wrote and published short stories and novelettes, while his father Carl (1840 1921) was the noted Austrian economist, one of the founders of marginal utility theory. A highly cultured man, and a liberal rationalist in the nine teenth century sense, the elder Menger had witnessed