In this article an attempt is made to suggest an explanation of some internal reasons for two interconnected tendencies in European culture. The first tendency is connected with a special way of creating frontiers in the European Union where they have now acquired a largely nominal character. The second tendency is a compulsive expansionism of European culture which, for long periods of time in the past, used to be realized in the shape of colonialism, and has now taken the form of globalization. Both these tendencies are connected with what the author defines as a “doubt imperative”, which is not only a constant “efficient cause” of scientific discourse, but also a means of constituting everyday reality. The article discusses both the thematization of this “doubt imperative” in the history of ideas of the modern philosophical tradition from Descartes to Husserl, and its current understanding as a model for business and everyday life. The compulsive reproduction of the “doubt imperative” makes it possible to draw the conclusion that the “doubt imperative” belongs to the basic spheres of modern European culture and consciousness, i.e., that it is connected with the basic structure and style of the process of constituting European reality.