Probability theory, which emerged as early as the 17th century thanks to the works of Pascal and Fermat, served for a long time as a tool of professional mathematicians. It was not considered a means of rational prediction of social actions. In the late 18th century, Nicolas de Condorcet (1743—1794) first proposed to apply probability theory to moral and political disciplines thus creating a basis for social forecasting. The methods he developed made it possible to predict the results of political elections and formed the basis for the theory of social choice. However, Condorcet’s ideas on the limits of mathematical constructs’ application in social and moral sciences opened up opportunities for social philosophy to go beyond the borders of speculative metaphysics and develop as a ‘practical’ science serving both the individual and the community. This paper also assesses Condorcet’s ideas in the history of probability calculus as a method to describe historical chronology. The nature of Condorcet’s thoughts on the wide interdisciplinary opportunities of mathematics makes it possible to compare his ideas with those of other philosophers of the Enlightenment (Rousseau, Montesquieu, Voltaire, and Diderot), as well as a number of provisions of Kant’s philosophy. Despite the fact that Condorcet was not familiar with Kant’s works, his general ideas on the autonomous subject, their reason and freedom, and history and social progress bear strong similarity to Kant’s views. However, the observed differences are indicative not only of Condorcet having overcome the prejudices of his time, but also of that his version of social, ethical, and political philosophy is alternative to Kant's theory of practical reason, as well as the philosophy of history of the Enlightenment and German rationalism.