Third Antinomy

Thesis Argument

P1 Suppose there were no freedom and that all causality occurs in accordance with the laws of nature.

P2  If all causality occurs in accordance with the laws of nature, then, for every event that happens, there must be a previous state from which it follows in accordance with the laws of nature.

C1 For every event that happens, there must be a previous state from which it follows in accordance with the laws of nature.  (from P1 and P2)

P3  If the state from which an event follows in accordance with the laws of nature had existed forever (i.e., were not an event, and thus did not come into existence and require a previous state from which it followed), then it could not have brought forth the event that is supposed to follow from it in accordance with the laws of nature.  (Kant remarks: “since if it [the state] had been at every time, then its consequence could not have just arisen, but would always have been” [A444/B472].)

C2  For any event that happens, the state from which it follows in accordance with the laws of nature is itself an event.  (from C1 and P3)

P4  If every event presupposes a preceding event from which it follows in accordance with the laws of nature, then there is never an absolutely first causal event and thus “no completeness of the series [of events] on the side of the causes descending from one another” (A446/B474).

C3  There is no completeness of causes for any event.  (from C2 and P4)

P5 If there is no completeness of causes for an event, then that event happens “without a cause sufficiently determined a priori” (A446/B474).

C4  Every event happens “without a cause sufficiently determined a priori.” (from C3 and P5)

P6  C4 is false; no event happens “without a cause sufficiently determined a priori.”

C5  P1 is false; there must be a kind of causality distinct from causality in accordance with the laws of nature, i.e., one that occurs without its cause being determined by another, previous cause—“an absolute causal spontaneity beginning from itself” (A446/B474) called transcendental freedom. (from C4 and P6)

 

Antithesis Argument

P1  Suppose there were freedom, i.e., a spontaneous (or uncaused) cause of the (absolute) beginning of a series of events.

P2  If a series of events were caused by a free or spontaneous cause, the spontaneous cause would not be caused by any previous state (or event) to be the cause of that series of events, i.e., “the determination of this spontaneity itself to produce the series … will begin absolutely” (A445/B473).

C1  A spontaneous cause is not caused by a previous state to be the cause of the series of events it causes. (from P1 and P2)

P3  For everything (or for every event) that happens, there must be a previous state from which it follows in accordance with the laws of nature.

C2  If a spontaneous cause happens (or begins to act), there must be a previous state from which it follows (causally) in accordance with the laws of nature. (from P3)

C3  A spontaneous cause is caused by a previous state in accordance with the laws of nature. (from P1 and C2)

C4  C1 and C3 are contradictory.  P1 must be false; there can be no freedom in the world.