The work compares the foundations of ontological teachings of M. Heidegger and A. F. Losev. Common to both thinkers is the understanding of the ultimate paradox of being. At the same time, there are serious differences in formal expression and methodological approaches. Therefore, the reduction of the corresponding comparative analysis to the search for external similarities and differences in their concepts means a simplification of the problem. Interpretations and comments of V. V. Bibikhin to the works of these authors open up the prospect of a nontrivial comparativism, which consists in the reconstruction of the historical premises of these teachings, as well as in revealing the «mirror» similarities of their original philosophical ideas. In particular, this can be found in the coincidence of the ontological intentions of the Losev’s dialectics of myth and the Heidegger’s event-ontology, in the context of their general criticism of rationalistic culture.