Agents—specifically, human beings—think, and they do so in accordance with rules. Saul Kripke’s provocative interpretation of Wittgenstein has inspired a rather large literature around the very question of what it would even mean to follow a rule. Yet well before considering that well-known, and vexing, difficulty, it is of some use to determine the precise (if only purported) function of a given rule, as well as its modal “status,” in order to see if any application of that rule can be justified: in Kant’s language, to establish the scope and limits of a rule and, in turn, a...

Kant conceives of general logic as a set of rules—exemplified by the Principle of Non-contradiction—that holds, universally and necessarily, for thought to be possible. For Kant, by reflecting on thought, we are able to identify and articulate those rules that are necessary for thought to be possible, and possible thought itself reveals those rules to be necessary.¹ This is the key to Kant’s transcendental method, whereby rules are revealed as universal and necessary relative to a given domain by reflecting on what must be the case for the judgments within that domain to be possible.

Within the domain...

Given his preoccupation with logic in the Critique of Pure Reason, it is an understandable hope that Kant might use the term “logic” in a clear-cut, univocal fashion throughout the text. Unfortunately, such a hope is mere fantasy; Kant uses the term in a bewildering variety of ways, at times making it close to impossible to determine whether he is referring to (among others) general logic, transcendental logic, transcendental analytic, a “special” logic relative to a specific science, a “natural” logic, a logic intended for the “learned” (Gelehrter), some hybrid of these logics, or even some still more abstract notion...

I have tried to show up to this point that Kant conceives of general logic as a set of universal and necessary rules for the possibility of thought, or as a set of minimal necessary conditions for ascribing rationality to an agent (focusing, up to this point, on the principle of non-contradiction). Such a conception contrasts with contemporary notions of formal, mathematical, or symbolic logic: rather as an attempt to identify those conditions that must hold for the possibility of thought, such conditions must hold a fortiori for any specific model of thought, including axiomatic treatments of logic and standard...

Up to this point, I have tried to clarify Kant’s conception of general logic as a set of universal and necessary rules ranging over the possibility of thought, relative to a generic kind of thinking subject. This subject is able to refer to itself using “I,” employs concepts to make judgments, and can regard itself as free. Relative, again, to this kind of subject, general logic functions to identify a set of conditions that this subject can come to see, reflectively, as necessary for the possibility of its own thought. Furthermore, any agent one takes to satisfy the above criteria—...

If we construe Kant’s general logic in the way I have urged in previous chapters, we see emerging a conception of logic that functions as a minimal-constraint model of rationality. In short, for an agent to be regarded as an agent—or for ourselves to regard ourselves as agents—we must conform to some set of rules for thought to qualify as thought. In Kantian terms, for a judgment in general to be possible, it must conform to a set of rules, and I have focused here on the principle of noncontradiction as exemplary of such a rule. When we...

It is not uncommon in introductory philosophy courses to receive a picture of Kant that paints him as a paradigmatic old-fashioned, detached Prussian scholar, whose walks were so predictable that the residents of Königsberg could set their clocks by them, and whose life passed as the most regular of regular verbs. Such an image is reinforced by the overwhelming attention to what might be called the “positive” dimension of Kant’s philosophy, for example, the Transcendental Analytic. There we find obscure arguments couched in arcane, inscrutable terminology, as well as intricate, elaborate proofs of synthetic a priori concepts and principles. All...