Is rebirth essential to Buddhist philosophy?

Elements of Buddhism can be rationally accepted such as the suffering that arises through attachment, the benefits of meditation, and even the acceptance of anatta, or non-self. It seems, however, that a belief in rebirth cannot be accepted *rationally*. A believer must suspend rationality to accept a theory that describes the migration of some level of consciousness across a lifetime. A common analogy used is the light emitting from a candle. Nothing *substantial* transmigrates, however something passes over from one life to the next. This theory cannot be directly perceived. Therefore, it cannot be tested, or verified rationally. It is simply a metaphysical inference. Buddhism encourages debate and questioning of its theories, and to not accept everything on face value. How then can a Buddhist test this theory? Can one disregard this element of Buddhism? Is it an *essential* aspect of the philosophy?