AVENARIUS, RICHARD. - Philosopher and physicist, b. in Paris in 1845, d. in Zurich in 1896. He taught philosophy at the University of Zurich. His principal work is Kritik der reinen Erfahrung (2 vols., 1888-1890), in which he expounds his philosophical system, which has taken the name of "empirio-criticism."
According to A., both a priori reasoning and practical life, by distorting it, influence the correct interpretation of the given data of experience; it is therefore necessary, through systematic criticism, to purify this given in order to found our knowledge on pure experience, both in the physical and in the psychic realm. His system thus consists of an extreme positivism. In applying it to psychic phenomena, A. upholds a theory that may be called biologico-materialistic, inasmuch as he considers them dependent on entirely material factors, namely, the intensity of excitation produced with regard to the external world, and nutrition with regard to the individual, i.e., his nervous system: the tone of psychic life would depend on the relationship between these two factors. The materialism and positivism of A. had notable influence only on certain materialist tendencies of today.