Note 1043 — Chapter II · DEDUCTION OF THE PURE CONCEPTS OF THE UNDERSTANDING (continued 3)

Cf. Metaphysical First Principles of Natural Science (1786), W. iv. pp. 470-1. It should be observed, however, that the reasons which Kant gives in this treatise for denying that psychology can ever become more than a merely historical or descriptive discipline are not that the objects of inner sense fall outside the realm of mechanically determined existence. Kant makes no assertion that even distantly implies any such view. His reasons are—(1) that, as time has only one dimension, the main body of mathematical science is not applicable to the phenomena of inner sense and their laws; (2) that such phenomena are capable only of a merely ideal, not of an experimental, analysis; (3) that, as the objects of inner sense do not consist of parts outside each other, their parts are not substances, and may therefore be conceived as diminishing in intensity or passing out of existence without prejudice to the principle of the permanence of substance (op. cit. p. 542, quoted below, p. 361, n. 2); (4) that inner observation is limited to the individual’s own existence; (5) that the very act of introspection alters the state of the object observed.