 This “fact” has caused considerable controversy among commentators. This is partly because Kant is not altogether clear about what he takes this fact to demonstrate. It is also because he has repeatedly argued that morality cannot be based on facts about human beings, and must be revealed a priori, independently of experience. (In this regard it is significant that Kant also uses the Latin word factum, meaning deed. In other words, we are dealing with an act of reason and its result, rather than a merely given fact. See Kleingeld 2010.) Moreover, Kant speaks of “cognizing the moral law,” when he is well aware that no author before him has formulated this law as he has. A final source of difficulty is that this “fact, as it were” does not feature in his earlier treatise, the Groundwork, and does not appear again.