This book tries hard to show what is the effective meaning of the fundamental concepts of the theory of crises. So it goes through the notions of the fall in the rate of profit, of overaccumulation, of crisis of surproduction, of devalorization of capital, etc. In contrast, the book strives to highlight that the representatives of the vulgar marxism, often from academics, give these concepts interpretations that bring Marx back into the fold of the political economy while all this work is aimed at the revolutionary criticism.