Full context:   According to Melford Spiro, this approach undermines the Four Noble Truths, for it does not address the existential question for the Buddhist as to "why live? why not commit suicide, hasten the end of dukkha in current life by ending life". In traditional Buddhism, rebirth continues the dukkha and the path to cessation of dukkha isn't suicide, but the fourth reality of the Four Noble Truths. The "naturalized Buddhism", according to Gowans, is a radical revision to traditional Buddhist thought and practice, and it attacks the structure behind the hopes, needs and rationalization of the realities of human life to traditional Buddhists in East, Southeast and South Asia. According to Keown, it may not be necessary to believe in some of the core Buddhist doctrines to be a Buddhist, but the rebirth, karma, realms of existence and cyclic universe doctrines underpin the Four Noble Truths in Buddhism.