Johann Friedrich Flatt (1759–1821) was a lecturer in theoretical philosophy in Tübingen from 1785–1791. As the resident Kant expert, during this time Flatt was responsible for reviewing both pro- and anti-Kantian works in the local academic journal, the Tübingische gelehrte Anzeigen. Flatt also reviewed Kant’s works themselves, including the Groundwork, translated into English in this chapter for the first time. The main theme of the review is Kant’s inconsistency, but Flatt also makes a claim that is repeated by other early critics, such as Tittel and Pistorius, namely that Kant’s own examples reveal that the categorical imperative cannot determine concrete duties without referring to experience, despite what Kant might say to the contrary. We have good reason to believe that Kant read Flatt’s review of the Groundwork, and Kant likely has Flatt in mind at 5:4.28–37n and 5:5.24–6.11 when discussing various alleged inconsistencies in his writings.