Not a Critique of books and systems.[333]—Kant here inserts a statement from the omitted Preface to the first edition.[334] He now adds that the Critique will supply a criterion for the valuation of all other systems.

A 13 = B 27.—Kant’s reason for omitting the title of Section II in the second edition was no doubt its inconsistency with the assertion of its opening sentence, viz. that the Critique is not transcendental philosophy, but only a preparation for it. Instead of it, Kant has introduced the more appropriate heading placed over the preceding paragraph.

The highest principles of morals do not belong to transcendental philosophy.[335]—Cf. A 801 = B 829. The alteration made in this passage in the second edition[336] indicates a transition towards the opposite view which Kant developed in the Critique of Practical Reason.[337]

The division of this science.[338]—Kant in this paragraph alternates in the most bewildering fashion between the Critique and Transcendental Philosophy. In this first sentence the Critique seems to be referred to. Later it is Transcendental Philosophy that is spoken of.

Doctrine of Elements and Doctrine of Methods.[339]—Cf. A 707 ff. = B 735 ff., and below, pp. 438, 563.

Two stems, sensibility and understanding, which may perhaps spring from a common root.[340]—Kant sometimes seems to suggest[341] that imagination is this common root. It belongs both to sensibility and to understanding, and is passive as well as spontaneous. But when so viewed, imagination is virtually regarded as an unknown supersensuous power, “concealed in the depths of the soul.”[342] The supersensuous is the point of union of our disparate human faculties, as well as of nature and freedom, mechanism and teleology.

The transcendental doctrine of sense would necessarily constitute the first part of the Science of Elements.[343]—“Necessarily constitute the first part” translates zum ersten Theile gehören müssen. This Vaihinger explains as an archaic mode of expression, equivalent to ausmachen. The point is important because, if translated quite literally, it might seem to conflict with the division actually followed, and to support the alternative division given in the Critique of Practical Reason. The first Critique is divided thus:

I. Doctrine of Elements.
1. Aesthetic.
2. Logic.
(a) Analytic.
(b) Dialectic.
II. Doctrine of Methods.

In the Critique of Practical Reason[344] a much more satisfactory division is suggested:

I. Doctrine of Elements.
1. Analytic.
(a) Aesthetic (Sense).
(b) Logic (Understanding).
2. Dialectic.
II. Doctrine of Methods.