Abstract: Shaped by biology and the modern Industrial Revolution, Engels’s concept of the unity of thinking and being frames cognition as a technological process akin to experimentation and rejects hard boundaries between the subject and object of cognition. This lays the theoretical groundwork for his realist theory. Engels’s realist theory—encompassing authenticity, tendency, and typicality—is grounded in his materialist epistemology and dialectics. In both its conceptual framework and its argumentative logic, it bears the clear imprint of Hegel’s philosophy and conceptual dialectics. It exhibits a structural isomorphism with Engels’s materialist epistemology and his critical transformation of Hegelian dialectics, and it strongly influenced the realist theories of Lukács, Lifshitz, Hu Feng, and Qian Gurong.

Key words: Engels, realism, Hegel, dialectics, isomorphism