Logical vs. Nonlogical Concepts: An Untenable Dualism?

One of the greatest disasters that befell twentieth-century analytic philosophy was Quine's (1953) rejection of the distinction between analytic and synthetic truths as an “untenable dualism”, to use Morton White's (1950) phrase. Or rather, the disaster was the widespread acceptance of this untenable rejection. It deprived philosophers of the means of mastering the defining concept of our era, the notion of information. It made it apparently pointless for them to use axiomatization or other kind of logical systematization as a tool of serious philosophical analysis, and hence encouraged the currently popular no-brainer appeals to “intuitions”. (cf. Hintikka 1999) These unfortunate consequences follow because on Quine's view a deduction of a theorem from axioms (and more generally a deduction of a consequence from premises) can introduce what for us is new factual information, for according to Quine such information cannot be separated from what for us is purely linguistic information. Hence the cognitive content (factual information) of a theory cannot be summed up in its axioms, for new assumptions can be introduced by the logical and mathematical methods used in the derivation of the theorems. This was precisely the kind of conundrum that the great David Hilbert sought to eliminate by means of his axiomatic approach, as shown by the sixth problem in his famous list of open problems. (See here e.g., Cory 1997, 1998; Majer 2001; and Yandell 2002)

In this paper, I will discuss one of the assumptions on which Quine's argument for rejecting the analytic-synthetic distinction rests. As I have pointed out before (Hintikka forthcoming (c)) the terms “analytic” and “synthetic” are most unfortunate from a historical point of view. What is meant is in fact a distinction between conceptual and factual information. Quine is right in effect pointing out that one cannot tell from a person's behavior whether the information he is relying on is factual or conceptual. But this interwovenness of factual and conceptual information can be much better explained by distinguishing from each other two different kinds of logical truths and accordingly two different kinds of information — much better than by abolishing the borderline between logical (conceptual) truths and factual truths, as Quine wants to do. (See here Hintikka, forthcoming (c)) Accordingly, Quine's accurate insight into (in effect) the behavioral indistinguishability of the two kinds of information does not mean that one cannot define the distinction by some other means. Indeed, it can be shown beyond any reasonable doubt that the usual logical truths of first-order logic are uninformative aka “tautological” in one basic sense of information.