This book is an attempt to understand the question: why I. Kant, the founder of the classical paradigm of thinking, was the inspiration for the most radical critics and reformers of classical rationality, such as M. Heidegger, M. Buber, J. Derrida, J. Deleuze , F. Guattari, S. Zizek, M. Mamardashvili. The ways of transformation of the most important concepts of Kantian philosophy among modern authors are considered. Modern versions of transcendentalism and immanentism are compared in terms of their roots in Kantian philosophy, their existential consequences are considered. The book is intended for philosophers and culturologists interested in the problems of rationality, postmodernism, modern culture.