Where the Enlightenment has claimed the space to answer its own questions, something new appears. In the German Republic of Letters between 1780-1790 a strident movement of thought advanced towards the borders of a true critique of Enlightenment. Mendelssohn, Reinhold, Wieland, Herder, Lessing and Schiller were central figures in German philosophy, questioning the nature and practice of the Enlightenment through resolute reflection on its limits. Kant’s essay, Beantwortung der Frage: was ist Aufklärung?, follows in their footsteps but also breaks away from this path. He leads us away from the obligatory content towards the courageous form of enlightened thinking: sapere aude! Those who can find the strength to think for themselves can be free from a self-imposed state of immaturity. However, a Self-Thinker never thinks alone according to Kant. His Aufklärungessay as well as his Kritik der Urteilskraft make it clear that thinking and judging for yourself are dynamic activities that always take the place of the other into account. They are exercises in freedom and effort is required to measure the universality of one’s own language to that of the other. Making public use of Reason is Kant’s ideal. Reason’s activity is only possible through speech and language, in a praxis and culture, through difference and debate. From a Lacanian point of view this is the place of the big Other, a universal field of signifiers circulating within our lacks, illuminating something of the desire of a subject. In this article the author addresses Kant’s idea of Enlightenment by relating it to Lacan’s notions of the big Other and the coming into being of the subject, in relation to this Other.