Abstract
Kant’s emphasis on the immorality of lying even to a murderer at the door who is asking about a victim hidden inside has drawn criticism ever since. The example originally given by Constant has been read as the thread of morality by totalitarian ruthlessness. In order to defend the importance of Kant’s moral philosophy, many critics have tried to update his position by taking into account the threat of modern totalitarianism. Nonetheless, this article tries to argue that Kant is right, especially since the rise of post-truth politics. Sincerity towards oneself and towards others remains the basis of democracy: we have to admit what seems to be the truth regardless of our feelings about it.