When we speak of a crisis in some domain, we usually think of an unfathomable situation which can only be resolved by a general upheaval. We can, however, assign another, more etymological meaning to the word: that of a critical evaluation. While admitting that the crises in contemporary physics have a good deal to do with the first meaning, I believe that their essential impact, on culture and human thought in general, issues from the second interpretation which allows us to envision these crises as a growing consciousness in physics of the range of its domain and the scope of its methods. These crises greatly contributed, on the one hand, to giving physics a new dimension in its field of action, and, on the other hand, they were brought about by a certain number of ideas which belonged to the general cultural heritage at the time they occured. From this point of view we may conceive of these crises as a cause, and conversely as an effect, of the penetration by wider intellectual horizons of an original structure which was somewhat artificially limited, by the selection of its constituent elements, to representing a sort of mental abstraction, justifiable in terms of the successes it achieved, but hardly representative of its human dimension as a whole.