"The Priority Principle from Kant to Frege" [[To appear in Noûs, 201?]]

In a famous passage (A68/B93), Kant writes that "the understanding can make no other use of [...] concepts than that of judging by means of them." Kant's thought is often called the thesis of the priority of judgments over concepts. We find a similar sounding priority thesis in Frege: "it is one of the most important differences between my mode of interpretation and the Boolean mode [...] that I do not proceed from concepts, but from judgments." Many interpreters have thought that Frege's priority principle is close to (or at least derivable from) Kant's. I argue that it is not. Nevertheless, there was a gradual historical development that began with Kant's priority thesis and culminated in Frege's new logic. In a famous passage at the beginning of the Transcendental Analytic in his Critique of Pure Reason, Kant claims that concepts are "predicates of possible judgments": Whereas all intuitions, as sensible, rest on affections, concepts rest on functions. By 'function' I mean the unity of the act of bringing various representations under one common representation. Concepts are based on the spontaneity of thought, sensible intuitions on the receptivity of impressions. Now the understanding can make no other use of these concepts than that of judging by means of them. [...] Concepts, as predicates of possible judgments, are related to some representation of a still undetermined object. The concept of body thus signifies "The Priority Principle from Kant to Frege" 2 something, e.g., a metal, which can be cognized through that concept. It is therefore a concept only because other representations are contained under it by means of which it can be related to objects. (A68-9/B93-4) The thesis expressed here is often called Kant's thesis of the priority of judgments over concepts, or just Kant's "priority principle" for short. The principle is rightly considered one of the most significant philosophical innovations in the first Critique, where it plays a central role in the central argument of the book. For this reason, several recent philosophical works have placed the principle at the center of their interpretations. In a number of writings, Frege makes a series of claims that have sounded to many interpreters much like the Kantian priority thesis. In fact it is one of the most important differences between my mode of interpretation and the Boolean mode—and indeed I add the Aristotelian mode— that I do not proceed from concepts, but from judgments. ("On the Aim of the 'Conceptual Notation'" [1882], Conceptual Notation and Related Articles, 94) As opposed to [Boole], I start out with judgments and their contents, and not from concepts. ... I only allow the formation of concepts to proceed from judgments. ("Boole's Logical Calculus and the Concept-script" [1880-1], Posthumous Writings, 16) Now I do not believe that concept formation can precede judgment because this would presuppose the independent existence of concepts, but I think of a concept "The Priority Principle from Kant to Frege" 3 as having arisen by decomposition from a judgeable content. (Letter to Marty [1882], Philosophical and Mathematical Correspondence, 100) The constellation of ideas expressed in these three passages is often called Frege's priority principle. Frege interpreters as diverse as Burge, Ricketts, Sluga, and Sullivan have each seen the principle as one of the most fundamental ideas – if need the fundamental idea – of Frege's logical writings. It is therefore of great interest to note that a host of Kant and Frege interpreters – including David Bell, Graham Bird, Robert Brandom, Tyler Burge, A.B. Dickerson, Michael Dummett, Michael Kremer, and Hans Sluga – have concluded that Frege's priority principle is identical to or derivable from Kant's principle. Frege thought of his priority principle, as we will see, as one of the most important differences between his logic and the traditional logic, and a key conceptual breakthrough that made possible the much greater expressive and inferential capacity of the Begriffsschrift. It would be very surprising indeed if this central Fregean idea were already contained in Kant's philosophy. Those interpreters who think that it is are therefore putting forward an unexpected claim: that Kant, whose conservative statements about Aristotle's logic are notorious (B viii), had within his own philosophy the seeds of modern logic. The effect of such an interpretation would be, I think, to play down Frege's originality and, I'll argue, underestimate the very substantial intellectual work that had to take place before Frege could write Begriffsschrift. When determining the relationship between Kant's thesis and Frege's thesis, we should not put too much weight on the fact that the ideas expressed by Kant and Frege in these passages can each be glossed as "priority theses." As Michael Dummett has "The Priority Principle from Kant to Frege"