The interwar verse of Aleksander Wat and Czesław Miłosz provides us with ample proof that both poets came to share a pessimism about the future course of European civilization. That belief led them both to develop a sympathy with the political left and, at the same time, an interest in religion. The shift to the left, however, was arrested as soon it became clear to them that this worldview offered no solution to the problem of evil in the world. Nor were they satisfied with the traditional answer to the question unde malum? that could be found in European culture rooted in its Catholic heritage. Having reached that point both poets turned to Gnosticism, a system of thought to which the problem of metaphysical evil is absolutely central. It is that philosophy and its rich symbolism that supplied them with a number of motifs to express their vision of the decline and fall of civilization. The article traces and analyzes the Gnostic ideas, motifs, images and symbols that express and give shape to the pessimistic vision of both Wat and Miłosz. It also argues that their ‘iconoclastic’ attitude which manifests itself among others in polemical reinterpretations of Old Testament texts is a consequence of their fascination with the Gnostic worldview.