Note 1239 — Chapter II · SYSTEM OF ALL PRINCIPLES OF PURE UNDERSTANDING (continued 2)
Reading edition
Cf. B 291-3, partially quoted above, pp. 310-11. In the Metaphysical First Principles (III. Lehrsatz, 4) the principle that action and reaction are always equal is similarly limited to the outer relations of material bodies in space, and Kant adds that all change in bodies is motion. Cf. W. xi. p. 234; and above, p. 147.