Moreover, since Kant in this passage speaks of space as a perception, and thereby identifies space with the perception of it,[12] the confusion may be explained thus. The form of phenomena is said to be the space in which all sensations are arranged, or in which all bodies are; space, apart from all sensations or bodies, i. e. empty, being the object of a pure perception, is treated as identical with a pure perception, viz. the perception of empty space; and the perception of empty space is treated as identical with a capacity of perceiving that which is spatial.[13] [4] 'Corresponds to' must mean 'is'. [5] B. 34, M. 21. [6] Cf. pp. 30-2. [7] It is impossible, of course, to see how such a process can give us knowledge of the spatial world, for, whatever bodies in space are, they are not arrangements of sensations. Nevertheless, Kant's theory of perception really precludes him from holding that bodies are anything else than arrangements of sensations, and he seems at times to accept this view explicitly, e. g. B. 38, M. 23 (quoted p. 41), where he speaks of our representing sensations as external to and next to each other, and, therefore, as in different places. [8] It may be noted that it would have been more natural to describe the particular shape of the phenomenon (i. e. the particular spatial arrangement of the sensations) rather than space as the form of the phenomenon; for the matter to which the form is opposed is said to be sensation, and that of which it is the matter is said to be the phenomenon, i. e. a body in space. [9] Cf. note 4, p. 38. [10] Cf. _Prol._ § 11 and p. 137. [11] Cf. p. 41, note 1. [12] Cf. p. 51, note 1. [13] The same confusion (and due to the same cause) is implied _Prol_. § 11, and B. 42 (b), M. 26 (b) first paragraph. Cf. B. 49 (b), M. 30 (b). The existence of the confusion, however, is most easily realized by asking, 'How did Kant come to think of space and time as the _only_ forms of perception?' It would seem obvious that the perception of _anything_ implies a form of perception in the sense of a mode or capacity of perceiving. To perceive colours implies a capacity for seeing; to hear noises implies a capacity for hearing. And these capacities may fairly be called forms of perception. As soon as this is realized, the conclusion is inevitable that Kant was led to think of space and time as the only forms of perception, because in this connexion he was thinking of each as a form of phenomena, i. e. as something in which all bodies or their states are, or, from the point of view of our knowledge, as that in which sensuous material is to be arranged; for there is nothing except space and time in which such arrangement could plausibly be said to be carried out.