Buddhist philosophy refers to the philosophical investigations and systems of inquiry that developed among various Buddhist schools in India following the death of the Buddha and later spread throughout Asia. Buddhism's main concern has always been freedom from dukkha (unease), and the path to that ultimate freedom consists in ethical action (karma), meditation and in direct insight (prajña) into the nature of "things as they truly are" (yathābhūtaṃ viditvā). Indian Buddhists sought this understanding not just from the revealed teachings of the Buddha, but through philosophical analysis and rational deliberation. 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 this path.
Early Buddhism was based on empirical evidence gained by the sense organs (ayatana) and the Buddha seems to have retained a skeptical distance from certain metaphysical questions, refusing to answer them because they were not conducive to liberation but led instead to further speculation. A recurrent theme in Buddhist philosophy has been the reification of concepts, and the subsequent return to the Buddhist Middle Way.
Particular points of Buddhist philosophy have often been the subject of disputes between different schools of Buddhism. These elaborations and disputes gave rise to various schools in early Buddhism of Abhidharma, and to the Mahayana traditions and schools of the prajnaparamita, Madhyamaka, Buddha-nature and Yogacara.