An introduction to logic and scientific method / Morris R. Cohen and Ernest Nagel. Cohen, Morris Raphael. 1880-1947. Nagel, Ernest, 1901-1985, joint author. Logic. Methodology. 160 COI "First edition." Includes bibliographies. New York : Harcourt, Brace and company, c1934. c1934. 1934 Text xii, 467 p. ; eng