What Men Live By (Czech: Čím lidé žijí) is an opera in one act by Bohuslav Martinů to an English[1] libretto by the composer, based on Where Love Is, There God Is Also (1885) by Leo Tolstoy, though he chose to use the more universal title of a different Tolstoy story What Men Live By (1886). It was composed in 1951-1952 when the composer was living in the United States,[1] and described by him as a 'pastoral-opera'.[2]