Joseph Petzoldt, a German empiriocritical philosopher, was born at Altenburg and taught mathematics and natural science at a Gymnasium in Spandau. In 1904 he became Privatdozent at the Technische Hochschule in Berlin-Charlottenburg, and in 1922 he was named associate professor. For a number of years he was chairman of the Gesellschaft für positivistische Philosophie.

Petzoldt was indebted to Ernst Mach's positivism, to the immanence philosophy of Wilhelm Schuppe, and above all to the empiriocriticism of Richard Avenarius. Petzoldt presented Avenarius's difficult philosophy in a popular form and developed it independently. For example, he offered a psychological explanation of the "narrowness," and therewith the unity, of consciousness; he tried to demonstrate the unlimited validity of psychophysical parallelism; and he analyzed ethical and aesthetic values and proposed a theory of the ethical and aesthetic permanence, or maximum stability, of humankind. According to this theory, all evolutionary processes...