If the Enlightenment turned to reason to reoccupy the place left vacant by the death of God, the history of the last two centuries has undermined the confidence that reason will bind freedom and keep it responsible. We cannot escape this history, which has issued in a pervasive nihilism and has rendered all appeals to the ethical questionable. Nor could Kierkegaard. The specter of nihilism haunts all of his writings, as it haunts already German romanticism, to which he is so indebted. To exorcize it is his most fundamental concern. And it is the same fundamentally religious concern that makes Kierkegaard so relevant to our situation: What today is to make life meaningful? If not reason, does the turn to the aesthetic promise an answer? To really choose is to bind freedom. Either-Or calls us to make such a choice, i.e. to be authentic. But what does it mean to be authentic? How are we today to think of such an authentic choice? As autonomous action? As a blind leap? As a leap of faith? Either/Or circles around these questions.