Buddhist philosophy refers to the philosophical investigations and systems of inquiry that developed among various Buddhist schools in India following the parinirvana (i.e. death) of the Buddha and later spread throughout Asia. The Buddhist path combines both philosophical reasoning and meditation. The Buddhist traditions present a multitude of Buddhist paths to liberation, and Buddhist thinkers in India and subsequently in East Asia have covered topics as varied as phenomenology, ethics, ontology, epistemology, logic and philosophy of time in their analysis of these paths.