The article provides proof that the concept of time articulated in Russian philosophy of the nineteenth century was very close to the understanding of time in the philosophy of Henri Bergson. This explains the close attention of Russian culture to the philosophical system of the French thinker at the beginning of the twentieth century. It also allows us to hypothesize about the possible influence of the ideas of Russian philosophers of the late nineteenth century on Bergson (more specifically, the influence of the ideas of Leo Tolstoy is justified). Bergson’s most original idea is the recognition of the metaphysical primacy of the subjective, inner time of the human in relation to physical time. In physical time, only the moment of the present has real existence; in internal time, designated by Bergson as duration, all moments of the past are preserved as real, and this is expressed by memory. Internal time turns out to be the spiritual Absolute from which the entire material world originates. A very similar metaphysical concept is presented in Pyotr Chaadaev’s Philosophical Letters. According to Chaadaev, each person is directly involved in the spiritual Absolute (God), which has the characteristic of integral time. In this time, all moments are in unity, and there is no division into the past, present, and future; this division arises only in the time intrinsic to the material reality that originates from the spiritual Absolute. In the religious teaching of Leo Tolstoy, personality is defined as the appearance of God within the limits of material existence, so a person is simultaneously involved in the earthly physical time and absolute time, which manifests itself through memory. The article concludes that Bergson’s ideas determined the most important features of Russian avant-garde culture of the twentieth century; in particular, thanks to them, the opposite trends of Russian thought were brought to unity: metaphysics of pan-unity and personalism.