Pistorius’ review of the Groundwork was without a doubt the most important early review, at least with respect to its influence on the second Critique. Pistorius raises several important objections in the review, many of which are now regarded as classic responses to Kant’s moral theory in the literature. These include: the empty formalism objection, the claim that Kant is a covert consequentialist, that only hypothetical imperatives can bind human beings, and that there is a distinction to be made between happiness through instinct and happiness through reason. Kant was aware of the review and responds to Pistorius explicitly in the second Critique, such as in the second chapter of the Analytic, where he replies to a “certain reviewer,” i.e., Pistorius, who claimed against the Groundwork that “the concept of the good was not established before the moral principle.” (5:8.27–9.2)