Purpose: Josef Mitterer’s essays are considered to be important philosophical advancements of radical constructivism. The main purposes of this paper are, on the one hand, to structure the RC landscape and, on the other hand, to investigate the relations of Mitterer’s work to radical constructivism in particular and to philosophy in general. Findings: In this short essay focusing on Mitterer’s Das Jenseits der Philosophie, I would like to stress two major points. First, Mitterer’s book should be considered as one of several contemporary variants of a radical critique of the semantic turn in the philosophy of science that has taken place since the mid-thirties with the works of Rudolf Carnap, Carl G. Hempel, Hilary Putnam, Alfred Tarski and others. Second, it is by no means clear how to determine the relevance of the new semantic critique for the present and future cognitive status of radical constructivism. The degree of relevance depends crucially on the use of the term “radical constructivism.” If radical constructivism, as I will argue, is seen as an umbrella term for a group of empirical research programs, then, by sheer necessity, the relevance can be marginal only. If, however, radical constructivism is viewed as a special form of philosophy of language and/or as a new epistemology, then the importance of Josef Mitterer’s approach must be judged within the context of available functional alternatives. Implications: An immediate consequence of this article lies in a renewed emphasis on advancing an empirical research agenda for radical constructivism and in an effective downsizing of radical constructivism as a philosophical perspective.