This paper is concerned with Beth’s reactions to logical empiricist doctrines, mainly during the period that logical empiricism did not yet belonged to the past, beginning with Beth’s first publication , and ending at the time that Beth formulated his own conception of scientific philosophy. In Beth’s development, three phases are distinguished; in the first period, which runs from 1933 to 1940, Beth’s appeal to “evidences” is seen as a fundamental difference with the views of the logical empiricists, though Beth stood sympathetic toward their rejection of metaphysics. During a short second period, from 1940 to 1942, Beth tried to establish a form of “modern metaphysics”, which he believed to account for the logical empiricist objections against traditional metaphysics, but after 1942, in his third period, Beth propagated a “scientific philosophy” in which all results are open to revision. However, he maintained, against the logical empiricists, a principal distinction between the natural sciences and the humanities (Geisteswissenschaften), on the basis of a general hypothesis, Beth’s “complementary principle”.