In his 1797 essay “On a Supposed Right to Lie from Love of Humanity”, Immanuel Kant argues that, when only a confident lie might save a friend, one must, if asked, reply truthfully and thus betray his hiding place to the person who wants to kill him. This is the first monograph that explores Kant’s essay in detail. Jens Timmermann examines the historical background of the piece (Kant was provoked by Benjamin Constant and his translator, Carl Friedrich Cramer), the history of the example (which is also discussed by, amongst others, Augustine, Johann David Michaelis and Johann Gottlieb Fichte), the peculiarities of Constant’s version of the case and Kant’s core argument against Constant: that lying, or a right to lie, would undermine contractual rights and spell disaster for human society.

The story of Kant’s essay “On a Supposed Right to Lie” is shrouded in mystery. Benjamin Constant’s essay “On Political Reactions” saddles an anonymous “German philosopher” with the view that lying is always wrong, even when a lie might be needed to save a friend’s life; and to date, Kant had not defended that view in print. Kant’s name was is mentioned only by Carl Friedrich Cramer in his German translation of Constant’s essay. So why did Cramer target Kant? And why did Kant play along, admitting he had defended absolutism in print when he had not? To complicate things further, Cramer mentions another German moralist, Johann David Michaelis, who endorses a view that is very similar to Kant’s, which is also examined in this chapter.