Oneness, Firstness, Causality

A fundamental ambition, at least in its earlier stages of development, of Kant's concept of Pure Practical Reason, is to attribute Firstness to Oneness, i. e. to establish the causal efficacy of the principle of Consistency.  According to his exposition, at least initially, the specific moment of that causality occurs when, in a rational being, the idea of Consistency effects respect for Consistency.  Eventually, however, he breaks that causal link, when he interposes freedom of choice.  But even prior to that modification, respect for Consistency means nothing more than constraint from an inconsistent course of behavior.  In other words, no effect follows from the idea of Consistency, thereby perfectly exemplifying Oneness as a principle of stasis, i. e. as no First.