The Buddhist approaches recognizes rebirth as well as karma. It starts from the mechanical recurrence proposition for the physical existence, and recognizes that there is an energy that propels this rebirth process forward according to the chain of cause and effect, karma. Buddhism however does not accept nor recognize any eternity to the soul; rather it treats the soul much in the same way it treats the body, as a phenomenon of the mechanical cause and effect which acts based on the desire-will.
Sri Aurobindo describes it thus: “As this constant hereditary succession of lives is a prolongation of the one universal principle of life by a continued creation of similar bodies, a mechanical recurrence, so the system of soul rebirth too is a constant prolongation of the principle of the soul-life by a continued creation through Karma of similar embodied associations and experiences, a mechanical recurrence. As the cause of all this physical birth and long hereditary continuation is an obscure will to life in Matter, so the cause of continued soul birth is an ignorant desire or will to be in the universal energy of Karma. As the constant wheelings of the universe and the motions of its forces generate individual existences who escape from or end in being by an individual dissolution, so there is this constant wheel of becoming and motion of Karma which forms into individualised soul-lives that must escape from their continuity by a dissolving cessation. An extinction of the embodied consciousness is our apparent material end; for soul too the end is extinction, the blank satisfaction of Nothingness or some ineffable bliss of a superconscient Non-Being. The affirmation of the mechanical occurrence or recurrence of birth is the essence of this view; but while the bodily life suffers an enforced end and dissolution, the soul life ceases by a willed self-extinction.”
The Buddhist view is, in its own right, an enormous progress from the view that treats life and physical existence purely as consisting of an essentially meaningless procession of days ending in death with no purpose or significance; but it does not yet provide us any affirmative rationale for the existence of the universe and the entire structure of life and being.