Kant’s Enlightenment appeal to his fellow men to have the courage to use their own understanding can be interpreted as a call to free oneself from all prejudices and to accept only those statements as true that have been recognised as true by one’s own reason or understanding. This appeal lives from the hope, which had already been expressed in Cartesian doubt, that there is a truth and that, in principle every human being is capable of recognising the truth. This truth bears the stamp of evidence, and since every human being has the same reason, this evidence can also be recognised by every human being. In this respect, it is up to every human being to subject the statements previously accepted by him as unquestioned prejudices to the critical gaze of reason, in order to accept them, if they withstand this gaze, as justified truths, or, if they do not pass the test of reason, to reject them as false or to dismiss them as uncertain. These prejudices included, above all, religious and political opinions.