In “On a Supposed Right to Lie from Philanthropy,” Kant holds the seemingly untenable position that lying is always prohibited, even if the lie is addressed to a murderer in an attempt to save the life of an innocent man. This article argues that Kant's position on lying should be placed back in its original context, namely a response to Benjamin Constant about the responsibility of individual agents toward political principles in post-revolutionary times. I show that Constant's theory of political (...) responsibility, which sanctions the lie, is not based on expediency, but on principled realism, whereas Kant endorses a position that I describe as ‘political juridicism.’ This analysis enables us to uncover two plausible Republican theories of political responsibility in post-revolutionary times behind an apparently strictly ethical debate. (shrink)