In his philosophy of life, Bergson’s aim is very clear: to determine, beyond mechanism and finalism, the essence of change and of evolution according to the order of duration in opposition to the order of space or juxtaposition. His intention is to penetrate the specificity of the order of duration. Regarding time, the analyses of the previous philosophers are proved to be deceiving, since all of them, according to him, ended up in reducing time to a succession of simultaneities. Founded on the order of magnitude, mechanism lines up succession as a series of numbers, finalism adds to succession the law of the better: in both cases all is already given and time is reduced to a mere appearance. Nowhere do we find a process in depth; as time is conceived as the realization of a programme previously arranged, everything is simply spread out in space.