i've never believed in reincarnation. the human soul is too obviously contingent, a product of its physical substrate and environmental pressures, and famously instable. at the "pulse of life" level, it is too generic and thoughtless, too deinviduated for a linear, body to body, journey. for this reason, a karmic doctrine asserting that the conditions for this current life have been set or in any way influenced by behaviors and preoccupations in a previous life have always struck me as either absurd or as an ideologically motivated ruse, one which paints the current situation as somehow pre-determined by the irretrievable, and thus unchangeable past. however, it is not unreasonable to claim that the lives we live have been set in motion by the actions of others, parents, grandparents, etc. and that we are carried along by the momentum of their dreams, their successes, their failures. we act out and out of their passions and, unless we take the time to consciously recollect our origins, or the origin of our origins, we do indeed live lives of a blind, karmic pre-destination.
On the other hand, karma is really just a doctrine of cause and effect. the entire universe is a complex chain reaction that goes on and on and on and, at least theoretically, there is a continuous chain of cause tying all current being to every other state of being, in its totality, stretching back to the primordial, original cause. There is no doubt that my behaviors, my actions, even my intentions, are part of an unbroken chain of physical events reaching back from this moment to the beginning of time, criss-crossing with innumerable other chains of discrete events, and carried along by the wave of all things happening forever. Reincarnation may simple mean that a particular chain, or more likely, complex of chains, has once again attained personhood. The exploration of past lives is always only an effort to understand this life and capture, in a highly symbolic narrative, the forces which have shaped both our proclivities and experiences.