This article is an attempt to present a comprehensive view of the poetry of Józef Czechowicz in the context of Martin Heidegger's fundamental ontology. Czechowicz's poetic work, the article argues, is an exploration of mutual relations of the basic ontological categories of being and nothingness ( das Sein and das Nichts). They constitute the philosophical foundations of the purely literary tensions that can be detected in all comprehensive accounts of his work, such as the opposition of Arcadia and Catastrophy (Tadeusz Kłak) or the discussion of the ‘bright’ and the ‘dark’ strain in the poetry of the Second Avant-garde (Jerzy Kwiatkowski).