3.7 A puzzle
4.1.1 Kant’s taxonomy of logics
First, a caveat. In the firstCritique, it is onlypure general logic, not logic simpliciter, that Kant takes to be formal. Logic, in the broadest sense of the term, is “the science of the rules of the understanding in general,” as opposed to aesthetic or “the rules of sensibility” (KrV:A52/B76). It has two main branches: general logic, which concerns the “absolutely necessary rules of thought without which there can be no employment whatsoever of the understanding,” andspecial logics, which concern “the rules of correct thinking as regards a certain kind of objects,” that is, the objects of a particular science (A52/B76). This dis-
tinction corresponds to theJ¨asche Logic’s distinction betweennecessary rules of cognition, “without which no use of the understanding would be possible at all,” andcontingent rules of cognition, “without which a certain determinate use of the understanding would not occur,” and “which depend upon a determinate object of cognition” (JL:12).3 Contingent rules are contingent in the sense that they are not universally applicable to thoughtas such:
Thus there is, for example, a use of the understanding in mathematics, in meta- physics, morals, etc. The rules of this particular, determinate use of the un- derstanding in the sciences mentioned are contingent, because it is contingent whether I think of this or that object, to which these particular rules relate. (JL:12)4
General logic, in turn, is divided into pure andapplied: pure general logic is an a priori science that abstracts entirely from contingent features of human psychology (memory, habits, etc.), while applied general logic considers empirical psychological principles that affect actual human thought. General logic is also distinguished fromtranscendental logic, which does not abstract entirely from objects and the content of thought, but “concerns itself with the laws of understanding and of reason solely in so far as they relate a priori to objects” (A57/B82). Kant does not say whether he takes transcendental logic to be a special logic, but there is good ground for thinking he does. He seems to regard the restriction of transcendental logic to objects capable of being given in human sensibility as adomain restriction, like the restriction of geometry to spatial objects. Thus, for instance, he characterizes the use of the understanding beyond the bounds set by transcendental logic as directed toward “. . . objectswithout distinction—upon objects which are not given to us, nay, perhaps cannot in any way be given,” that is, toward “objects in general” (A63/B88, my emphasis). Similarly, in theJ¨asche Logic, he says that transcendental logic represents the object “as an object of the mere understanding,” while general logic “deals with all objects in general” (JL:15). And in R:1628 (at 44.1-8), Kant uses “objects of experience”
3See section 3.1, above.
4The JL, which was put together from Kant’s notes and annotations, must be used with care as
a source for Kant’s views on logic. See Longuenesse 1998:81 n. 1 and Young’s introduction to Kant 1992:xviii. In general, I take it to be a fairly reliable guide. Much of its content can also be found in other transcripts of Kant’s logic lectures, or in Kant’s published works.
as an example of a particular domain of objects that would require special rules (presumably, those of transcendental logic)—as opposed to the “rules of thinking uberhaupt¨ ” contained in general logic.5 All of these passages suggest that Kant takes transcendental logic to be a special logic. However, the evidence is not conclusive. Kant characterizes the special logics as organa of the various sciences (A52/B76), and in places, he denies that transcendental logic is anorganon.6 For now, we will leave the question open (see figure 4.1).
Figure 4.1: Kant’s taxonomy of logics.
LOGIC
(the science of the rules of the understanding in general)
GENERAL (absolutely necessary rules of thought which apply without regard
to differences in the object)
SPECIAL (rules of correct thinking as regards a certain kind of object:
organonof this or that science)
TRANSCENDENTAL (laws of understanding and reason in so far as they relate
a priori to objects)
PURE
(abstracts from empirical psychology: acanonof understanding and reason, in respect of what is formal in
their employment)
APPLIED (considers empirical conditions
of use of understanding:
catharticof common understanding)
Of these divisions, only pure general logic corresponds to what we now call “logic.” The special logics contain the principles of particular sciences, insofar as these can be seen as defining “forms of thought” characteristic of these sciences (JL:18, PL:508). Applied logic,
5“Aber nachdem die obiecte Verschieden seyn, m¨ussen auch verschiedene Regeln des Denkens
seyn, z. B. Andere Regeln im Gegenstand der Erfahrung als im Gegenstand der blossen Vernunft (Tugend), andere Regeln des Verstandes vor ¨aussere Erfahrung als vor innere. Jede Wissenschaft hat ihre besondere Regeln. // Es muss aber doch auche eine Geben, die vor allen Wissenschaften vorhergeht und die Regeln des Denkens ¨uberhaupt enth¨alt. Hier muss von allem unterschiede der obiecte abstrahirt werden.”
6For example, at R:2162: “In der transcendentalen Logik ist die materie allgemein bestimt und
unterschieden; daher criterien der warheit, aber kein organon.” But compare A1011/B245, where the Critique of Pure Reason is said to be “a special science” aiming at an “organon of pure reason.”
on the other hand, is properly a part of psychology. In theJ¨asche Logic, Kant denies that it ought to be called logic at all, on the grounds that “[i]t is a psychology in which we consider how things customarily go on in our thought, not how they ought to go on” (JL:18). Only pure general logic and transcendental logic have the general applicability and normative character we associate with logic. But transcendental logic concerns itself with the relation between thought and its objects, and hence with intuition and sensibility: we would call it epistemology or semantics (in a broad sense), not logic. Even Kant often uses the term “logic” in the stricter sense of “pure general logic” (e.g., KrV:B ix, A61/B86, A598/B626; JL:13, 14). And when logic (rather than critical philosophy) is his topic, hedefines logic in a way that excludes transcendental logic.7 In what follows, I will use “logic” to mean “pure general logic,” unless I explicitly specify otherwise.