“Ratiofundamentalism and Its Overcoming” is an original investigation demonstrating the insufficiency of the old approaches to the tasks of rational mind (of the scientific rationality), and first of all, to “theory” and “experience” interpretation, as the tasks of taming nature by human rationality. Not only the failure of the “empiricism” program in the modern physical-cosmological knowledge is made clear, but also the expectancies of the “communicative program” in epistemology are subjected to a profound criticism. The logical-epistemological unfoundedness of the main propositions of the communicative program is demonstrated: “general validity” takes the place of “truth”, “communicative action” – the place of “theory”, and “society” – the place of “an individual”. It is also shown that ratiofundamentalism was initiated in the history of European rationality by René Descartes who treated the old Parmenides’ identity of thinking and being in his own way. The book on the whole may be of interest for specialists in methodology and philosophy of science, as well as for those who care anyhow about the transformations of the European scientific rationality.