The article analyzes the ontological ideas of Graham Harman and Quentin Meillassoux. The author establishes that Harman's object-oriented ontology defends the principle of horizontality, while Meillassoux's philosophy is anthropocentric and therefore hierarchical. The concepts of the non-human are defined in both approaches. Harman's universe, consisting of objects of equal ontological status, is analyzed. The principle according to which new objects appear in the world is explicated. The theory of accident in the interpretations of Meillassoux and Harman is investigated. The Meillassoux contingency is fulfilled by the principle of identity, while, for Harman, accident has the property of inconsistency. Further, the relation of these concepts to the themes of classical ontology is investigated. It turns out that the thesis of the identity of being and thinking is defended by Meillassoux and is criticized by Harman. Meillassoux believes that he succeeds in substantiating the absolute subjective cognizability of the non-human world and, consequently, in restoring the principle of identity. Object-oriented ontology (OOO) sees in identity a return to the ontological hierarchy and anthropocentrism. Meillassoux also claims that the denial of the principle of sufficient reason allows him to create a non-metaphysical ontology. On the contrary, Harman defends this principle, and, moreover, makes it "infinite". The author also establishes that OOO is skeptical about the ideas of ontological knowledge and truth, while Meillassoux acts as an optimist in this regard. For Meillassoux, direct ontological cognition is possible by appealing to reason and mathematics; in turn, Harman allows only indirect cognition, and entirely in the form of aesthetics. Both approaches agree that the universe cannot have, firstly, a finite number of elements and, secondly, one element that would unite all the others. The author argues that the concepts of Harman and Meillassoux seek to include the sphere of the non-human in contemporary ontology as a theme that has always been mainly on the periphery of European thought. In addition, Meillassoux wants to restore respect for rationality and exact sciences to continental philosophy, while the Harman approach promises to expand the field of ontological work. The author concludes that, against the background of the named advantages and points of contact, it is worth striving for the synthesis of these ontologies.
