Buddhism treats death as just one aspect of the cycle of life and change which characterizes mortal existence. All material things are taken to have come into existence out of some prior cause and are part of the process of creation, persistence, transformation and extinction. The cycle of birth and rebirth, samsara, can only be transcended by achieving enlightenment, and even then the Bodhisattva may decide that an individual enlightenment without the enlightenment of everything is not worth having, and so he or she may descend back into samsara in order to help others.