This essay discusses Lessing’s idea of truth. I interpret Lessing’s scepticism against any form of absolute truth as a fundamental caveat against totalitarian thinking, no matter if religious or secular. Instead of following the autoritarian enlightenment’s idea of absolute truth, Lessing rather goes back to the early enlightenment tradition of sceptical thinking, which he augments with a specifically pluralistic concept of thruth(s). It is Lessing’s fundamental opinion, that every truth is uncertain and that therefore tolerance is necessary: His concept of tolerance is thus based on the uncertainty of knowledge, not on the certainty of one’s own knowledge (or conviction), because this would only allow to be tolerant in an humbling way. With the help of this concept of truth and tolerance, Lessing develops an autonomous position concerning the realm of historical truths, a position which enables man to discover thruth and to act according to universal values. This position is at the heart of Lessing’s idea of the domestic tragedy (bürgerliches Trauerspiel), and it is the centre of his poetical as well as his theoretical writings.