The Buddhist belief in rebirth or reincarnation is shared with other Indian faiths. An individual's mental continuity, which includes their instincts, abilities, and other traits, originates in previous lifetimes and continues into subsequent ones. An individual may be reincarnated in any of a broad range of life forms, better or worse: human, animal, bug, even ghost and other unseen states. This depends on one's activities and the propensities built up by them. Due to the power of their problematic attitudes, such as attachment, rage, and naivete, and the compulsive behaviour that is sparked by them, all creatures undergo uncontrollable rebirth. If one acts destructively on negative impulses that occur in one's head as a result of past behavioural patterns, one will suffer and be unhappy. Happiness, on the other hand, can be obtained through engaging in productive activities. In subsequent rebirths, each individual's happiness or unhappiness is not a reward or a punishment, but is formed by that person's previous acts according to the principles of behavioural cause and effect.

How Can We Learn About Rebirth?
How can we be certain that anything is true? Things can be validly known in two ways, according to Buddhist teachings: by direct perception and through inference. We can prove the existence of anything through simple perception by doing an experiment in a laboratory. For example, we know it's true, merely by seeing under a microscope, that there are numerous small bacteria in a drop of lake water.

Some things, however, cannot be known through simple perception. We must rely on logic, reason, and inference; for example, we can deduce the presence of magnetism from the behaviour of a magnet and an iron needle. Rebirth is extremely difficult to demonstrate with just sense perception. However, there are several examples of persons who recall previous incarnations and can identify personal objects or people they knew. We could deduce the existence of rebirth from this, but some people may be sceptical and suspect a ruse.

Leaving aside those reports of former life recollections, reasoning could help us explain rebirth. His Holiness the Dalai Lama has stated that if particular points do not relate to reality, he is willing to have Buddhism eliminate them. This also pertains to rebirth. In fact, he made this statement in that context originally. If science can establish that rebirth does not exist, we must abandon our belief in it. If scientists cannot prove it incorrect, they must study if it exists because they follow logic and the scientific method, which is open to new ideas. They would have to discover the absence of rebirth in order to show its absence. Simply asserting, "Rebirth doesn't exist because I don't see it with my eyes," does not prove rebirth's nonexistence. There are many things that we cannot see with our eyes, such as magnetism and gravity.