Ernst Moses Marcus (3 September 3, 1856, Kamen – 30 October, 1928 Essen) was a German lawyer and philosopher. He developed a theory of aether based on Immanuel Kant's posthumous work Opus Postumum, however sharply disagreeing with Erich Adickes interpretation. He used this to mount a criticism of Albert Einstein's theory of relativity. He was a major influence on Salomo Friedlaender. Ernst was the son of Robert Ruben Marcus and Berta Marcus. Marcus studied law in Bonn and Berlin. Whilst working as an Assessor in 1889 he developed an interest in philosophy. In 1890 he was appointed as a judge in Essen. In 1893 he married Berta Auerbach with whom he had three children. In 1899 he started regular meetings with Salomo Friedlaender who admired his theses and became a firm supporter of him. Friedlaender referred to him by epithet the "Krupp of logic". Source: Wikipedia (en)