Quelques éléments de réflexion au sujet des cycles Kondratieff

The Kondratieff cycle has been put back in the forefront for two decades now by the contemporary crisis, whose structural and durable character is more than ever perceptible. This cycle is, however, now as in the past, still deeply controversial. The object of this paper is not to take stock of the present state of the debate and of the questioning on this topic, but, more modestly, to draw attention to a few fundamental problems relative to the field of investigation that has been constituted around this set of problems. In fact, it seems that the reflection concerning the long cycles of capitalist growth leaves in abeyance numerous questions unanswered or at least insufficiently taken into account in contemporary explanations. Five points are tackled one after the other : the question to know whether the fluctuations of the Kondratieff type are proper or not to the era of industrial capitalism; the problem of the enumeration of the different types of economic fluctuations; the question of «longterm prices» and the dating problem, with regards to the periodicity and cyclical nature of the move- ments ; lastly, the questions of wars. The idea, which is finally formulated, is that the credibility of the set of problems concerning long cycles depends more than ever on giving clear and coherent answers to these questions.