Rudolf Carnap (1891–1970), Austrian U.S. philosopher of science, logical positivist. repr. in The Philosophy of Science, pp. 85-97, eds. R. Boyd, Gasper and Trout (1950). Original journal article in Revue International de Philosophie 11, "Empiricism, Semantics, and Ontology," (1950).
The author's famous plea for tolerance to which W.V. Quine took exception.