What does "critical mathematics education" mean? This is the essential question addressed in this text. The question forms the basis of an approach to the clarification of such notions as: crises, democracy, the Vico-paradox, mathematical formatting, reflective knowing, learning as action, personal fatalism and underground intentions. The subject matter considered is the project-organized mathematics education undertaken in primary and secondary school. It is shown that the concept of critical mathematics education is crucial for every educational theory. The book explains that if humanity is submerged in technology, and if modern technology is to a great extent constituted by mathematics, then the implicit and explicit functions of mathematics education assume a fundamental importance.