Richard Heinrich Ludwig Avenarius (1843-1896), German philosopher, was born in Paris on the 19th of November 1843. His education, begun in Zürich and Berlin, was completed at the university of Leipzig, where he graduated in 1876. In 1877 he became professor of philosophy in Zürich, where he died on the 18th of August 1896. At Leipzig he was one of the founders of the Akademisch-philosophische Verein, and was the first editor of the Vierteljahrsschrift für wissenschaftliche Philosophie. In 1868 he published an essay on the Pantheism of Spinoza. His chief works are Philosophie als Denken der Welt gemäss dem Princip des kleinsten Kraftmasses (1876) and the Kritik der reinen Erfahrung (1888-1890). In these works he made an attempt to co-ordinate thought and action. Like Mach, he started from the principle of economy of thinking, and in the Kritik endeavoured to explain pure experience in relation to knowledge and environment. He discovers that statements dependent upon environment constitute pure experience. This philosophy, called Empirio-criticism, is not, however, a realistic but an idealistic dualism, nor can it be called materialism.
See Wundt, Philos. Stud. xiii. (1897); Carstanjen and Willy in Zeitsch. f. wiss. Philos. xx. (1896), 361 ff.; xx. 57 ff.; xxii. 53 ff.; J. Petzoldt's Einführung in d. Philos. d. reinen Erfahrung (1900).