Abstract: The object of this work is the philosophy of T. Hobbes in its integrity and unity of its main parts, including logic, the so-called "first philosophy", physics, the doctrine of man, the doctrine of morality, politics and law. The subject is the internal connection of the concept of the Leviathan state with the theory of cognition and ontology in the context of a number of problems of modern epistemology, philosophy and the history of science and the history of philosophy of Modern times. Methodologically, the work is based on a comparative historical approach, hermeneutic analysis of sources, as well as general scientific methods of analogy, generalization, abstraction, systematization, and others. Results of the study: 1) T. Hobbes is not so much an experimental theorist as a popularizer of science, confident that such popularization in itself can both lead a person to the truth and help solve a number of socio-political problems; 2) Hobbes' attitude radically breaks with a number of provisions of both the philosophy of nature and socio-in the political philosophy of Antiquity, translating the aporicity of the latter into paradoxicity and, as a consequence, antinomianism; 3) T. Hobbes discovers the logically abstract world of science as an analytical-synthetic transformation of the everyday world given in sensation, while the first necessarily generates something third - a world that exists by itself, an unknowable world; this makes him to strictly approach the definitions of the boundaries of knowledge — God, soul, morality and law; 4) the concept of Leviathan solves the problem of the mutual transition of the universal and the individual in a very typical way for early Modern times — through the fundamental paradox of the interaction of the abstract scientific world of science and the "objective" world itself opposed to it; this paradox is one of essential features of philosophy and science of early modern times.