Abstract: This article examines the philosophical grounds of the modern concept of democracy on the basis of Cartesian tradition demonstrated in works of Alexis de Tocqueville and Jean-Paul Sartre. The philosophical-anthropological interpretation of Descartes by the two French thinkers of different generations raised new questions and offered new answers important for understanding the essence of Western democracy. They believed that the achievement of Descartes mostly lies in the fact that he posed the problem of free and independent reasoning, which is the foundation of democratic regime. The article applies the method of philosophical comparative studies, axiological and anthropological approaches. The author’s main contribution into the research of this topic is defined by the fact that he traced the French contribution into the American strategy of “self-sufficient” thought, and afterwards, having returned to the French context, examines what was exactly borrowed by the political theory and social knowledge that developed the idea of democracy within the methodological doubt of Descartes.