Herbert G. Bohnert (1918–84) was a student and lifelong friend of Carnap. He wrote a doctoral thesis on Ramsey sentences and, after wavering between academia and the computer industry, eventually taught at Michigan State University. Bohnert defended Carnapian positions throughout his career and was especially productive in the 1970s. Unfortunately, Carnap’s philosophy was deemed hopelessly out of date during this period, and partly for this reason, Bohnert is almost completely forgotten today. This fate is undeserved. In this article, I reconstruct (...) his career and philosophical development by drawing on publications, as well as diary entries and private correspondence. I then argue that Carnap scholarship would benefit from closer attention to Bohnert’s writings. I support this claim by means of a case study from the philosophy of mathematics: Bohnert’s account of a conversation about set theory with Carnap in 1968 sheds new light on the contested question of whether Carnap held mathematics to be analytic in natural language. (shrink)

The nature of the connection between theory and observation has been a major source of difficulty for philosophers of science. It is most vexing for those who would reduce the terms of a theory to those of an observation language, e.g. Carnap, Braithwaite, and Nagel. Carnap's work, particularly his treatment of physical theories as partially interpreted formalisms, forms the point of focus of this paper. Carnap attempted to make the connection between theory and observation through correspondence postulates. It is pointed (...) out that such postulates depend in critical ways upon theoretical truths. This particular type of theoretical dependence produces serious trouble for Carnap's approach. For reasons given it may make it untenable. Furthermore, this problem when generalized creates difficulty for any similar reductionist program. Not only is this kind of theoretical dependence pointed out, but more important, the logical conditions which produce it are revealed. In this way light is shed upon the formal characteristics of the notion of theory dependence, especially upon the way in which observation terms depend upon theories for their meaning. (shrink)

In this paper Rudolf Carnap's definition of 'analytic truth' based upon a meaning postulate At, for theoretical predicates of a given scientific theory is subjected to critique. It is argued that this definition is both too exclusive and too inclusive. Assuming that the preceding is correct, At is subjected to further scrutiny to determine how to interpret it and whether, and under what conditions, it need even be true. It is argued that a given At need not be true as (...) a sentence in a scientific theory and that it must be regarded as a confusedly presented rule for the same. It is then argued that even as a semantical rule for the theory, At cannot provide a guarantee of truth for some meaning postulate similar to At in the theory itself. It is thus argued that Carnap's definition of 'analytic truth' for theoretical predicates is unsatisfactory. (shrink)