Chapter Six assesses the most difficult problem for a naturalist interpretation of Kant’s ethics: freedom of the will as the freedom of the power of choice in making a decision uncaused by anything in nature. Practical freedom, in contrast, involves the empirical power of choice within nature determined by empirical reason. The bulk of the chapter argues that Kant requires only one non-natural choice, not a multitude as some commentators prefer. Kant insists that free choice is needed for two reasons, related to ought-implies-can and moral responsibility, and in both cases his discussions involve only one non-natural free choice. This single timeless choice of the entirety of one’s phenomenal character is the best interpretation of his claims about freedom, timelessness, distinct causality, and the intelligible character in relation to free choice. While still unnatural, it is at least the minimal non-natural interpretation. The last part of the chapter goes further to stress the status of freedom as a postulate, something Kant himself does not do, allowing for a naturalistic interpretation of this non-natural choice as a concept merely playing a heuristic role in moral life similar to use of the concept of God.