- Necessity and Possibility: The Logical Strategy of Kant's Critique of Pure Reason
This book is a foray into the thorny interpretive issue of what to make of Kant's so-called "Metaphysical Deduction" of the categories. As with many of the arguments in the first Critique, the claim of the Metaphysical Deduction is easier to make out than its argument. The claim is that by some or other reference to "general logic," one may obtain a "transcendental logic," i.e., a justification (or "deduction") of the categories (of the understanding) necessary to the (very) possibility of experience. But how? By, Kant says, discerning, in general logic, a "clue" to transcendental logic. But what sort of clue? And then what clue exactly? We need a meta-clue to get a clue.
Herein lies the very mixed reception the Metaphysical Deduction has met. Depending on how one interprets 'clue' (Leitfaden), one may treat the claim of the Metaphysical Deduction as a bit of a sham—overblown, unsubstantiated, and eminently dispensable (the consensus, more or less, of much nineteenth-and twentieth-century commentary)—or, on a rarer view, one may treat it as the ticking heart of the whole deal (as in Beatrice Longuenesse's Kant and the Capacity to Judge [Princeton, 1998]). Neither extreme is quite persuasive, and if Mosser's more temperate interpretation comes across as somewhat tepid, it also comes across as more plausible.
Before setting out his account of the relation between general logic and transcendental logic such that the one is a clue to the other, Mosser dispatches two traditional bugaboos, viz. that the categories cannot be "derived" from the judgment forms, and that, contrary to Kant's claim, the tables of judgment forms and categories are not "complete." Mosser argues convincingly that the question of deriving the categories from the forms of judgment was not Kant's concern and is pretty much a red herring. As for Kant's "completeness" claim, Mosser offers two vindicatory suggestions. Kant may simply be adhering to his unargued faith that "what reason produces out of itself cannot be hidden" (KrV Axx), and/or he has gone "regulative": "Kant's introduction to the Analytic of Concepts would seem to suggest that the completeness of the transcendental analytic is grounded in a maxim of reason, and thus involves a regulative employment of the idea of totality" (102). In any case, Mosser further argues, what really matters is the necessity of a given set of judgment forms to the possibility of thought, and not the completeness of the set. I am sympathetic to this defense of Kant although, as I shall suggest, it risks forgoing the best clue to the clue.
By 'transcendental logic', Kant means an account of things that "isolates" the understanding no less than "transcendental aesthetic" isolates sensibility (KrV A62/B87). How is general logic a clue to this? Mosser's answer is a relatively moderate and deflationary one: by analogy. "The central line of argument I have been attempting to develop here is straightforward: a logic is the systematic presentation of rules that range, universally and necessarily, over a given domain. Kant argues that just as the rules of general logic universally [End Page 402] and necessarily range over the domain of possible thought, the rules of transcendental logic—specifically transcendental analytic—range over the domain of possible experience" (107). Kant's Leitfaden leads by example. This is the nub of Mosser's account.
Though he has much else of interest to say, one may feel that Mosser's nub does not quite coincide with Kant's nub (and there is the rub). The latter, it is widely conceded, is presented by Kant just before he sets the table of the categories: "The same function that gives unity to the different representations in a judgment also gives unity to the mere synthesis of different representations in an intuition, which expressed generally, is called the pure concept of understanding" (KrV A79/B105). Mosser notes and discusses...