The word "antinomy" lets us think of Kant. One thing this book attempts to show is that Kant's antinomies open a way towards an overcoming of that nihilism that is a corollary of the understanding of reality that presides over our science and technology. But when I am speaking of the antinomy of Being I am thinking not so much of Kant, as of Heidegger. Not that Heidegger speaks of an antinomy of Being. But his thinking of Being leads him and will lead those who follow him on his path of thinking into this antinomy. At bottom, however, I am concerrned with neither Heidegger's nor Kant's thought: I shall try to show that our thinking inevitably leads us into some version of this antinomy whenever it attempts to grasp reality in toto, without loss. All such attempts will fall short of their goal. And that they do so, I will claim, is not something to be grudgingly accepted, but embraced as a necessary condition of living a meaningful life. That is why the antinomy of Being matters and should concern us all.