August Ludwig Christian Heydenreich’s On Freedom and Determinism and their Compatibility (1793) presents the central tensions between determinism and indeterminism prior to the Critical philosophy and outlines how the latter is able to resolve these tensions. He notes that for all that Kant’s conception of free will was able to accomplish, there is still considerable disagreement on how this conception is to be understood, particularly between Carl Christian Erhard Schmid and Karl Leonhard Reinhold. The originality of Heydenreich’s position consists in his assertion that the moral power of choice cannot belong to the sphere of nature or to the supersensible world. If it belonged to the former, then its actions would necessarily be determined in accordance with the law of causality. If it belonged to the latter, then its actions would necessarily be determined by the moral law and culpability for immoral actions would be abolished. Instead, the moral power of choice must be situated between the two realms and constitute the boundary and bridge between them.

Karl Heinrich Heydenreich contends in “On Moral Freedom” (1791) that the human being is originally endowed with consciousness of freedom. Moreover, Heydenreich explicitly denies that our consciousness of freedom is a consequence of consciousness of the moral law and instead maintains that the moral law provides only indirect support for our innate consciousness of freedom. Similar to Snell’s contention that our freedom is revealed to us through the feeling of our own self, at one point Heydenreich refers to our feeling of freedom. According to Heydenreich, the task of philosophy is to secure this feeling of freedom from the skepticism of speculative reason.