The Buddhist view is that each living being has a continuity or stream of consciousness that moves from one life to the next. Each being has had countless previous lives and will continue to be reborn again and again without control unless he/she develops his/her mind to the point where, like the yogis mentioned above, he/she gains control over this process. When the stream of consciousness or mind moves from one life to the next it brings with it the karmic imprints or potentialities from previous lives. Karma literally means “action”, and all of the actions of body, speech and mind leave an imprint on the mind-stream. These karmas can be negative, positive or neutral, depending on the action. They can ripen at any time in the future, whenever conditions are suitable. These karmic seeds or imprints are never lost.
At the time of death (clear light stage) the consciousness (very subtle mind) leaves the body and the person takes the body of an intermediate state being. They are in the form that they will take in their next life (some texts say the previous life), but in a subtle rather than a gross form. As mentioned previously, it can take up to forty-nine days to find a suitable place of rebirth. This rebirth is propelled by karma and is uncontrolled. In effect the karma of the intermediate state being matches that of its future parents. The intermediate state being has the illusory appearance of its future parents copulating. It is drawn to this place by the force of attraction to its parent of the opposite sex, and it is this desire that causes the consciousness of the intermediate state being to enter the fertilized ovum. This happens at or near the time of conception and the new life has begun.