Buddhist philosophy is the ancient Indian philosophical system that developed within the religio-philosophical tradition of Buddhism. It comprises all the philosophical investigations and systems of rational inquiry that developed among various schools of Buddhism in ancient India following the parinirvāṇa of Gautama Buddha (c. 5th century BCE), as well as the further developments which followed the spread of Buddhism throughout Asia.
Buddhism combines both philosophical reasoning and the practice of meditation. The Buddhist religion presents a multitude of Buddhist paths to liberation; with the expansion of early Buddhism from ancient India to Sri Lanka and subsequently to East Asia and Southeast Asia, Buddhist thinkers have covered topics as varied as cosmology, ethics, epistemology, logic, metaphysics, ontology, phenomenology, the philosophy of mind, the philosophy of time, and soteriology in their analysis of these paths.
Pre-sectarian Buddhism was based on empirical evidence gained by the sense organs (including the mind), 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. However he also affirmed theories with metaphysical implications, such as dependent arising, karma, and rebirth.
Particular points of Buddhist philosophy have often been the subject of disputes between different schools of Buddhism, as well as between representative thinkers of Buddhist schools and Hindu or Jaina philosophers. These elaborations and disputes gave rise to various schools in early Buddhism of Abhidharma, and to the Mahāyāna traditions such as Prajñāpāramitā, Mādhyamaka, Sautrāntika, Buddha-nature, and Yogācāra. One recurrent theme in Buddhist philosophy has been the desire to find a Middle Way between philosophical views seen as extreme.
Historical phases of Buddhist philosophy
Edward Conze splits the development of Indian Buddhist philosophy into three phases:
The phase of the pre-sectarian Buddhist doctrines derived from oral traditions that originated during the life of Gautama Buddha, and are common to all later schools of Buddhism. The second phase concerns non-Mahāyāna "scholastic" Buddhism, as evident in the Abhidharma texts beginning in the 3rd century BCE, that feature scholastic reworking and schematic classification of material in the early Buddhist texts. The Abhidhamma philosophy of the Theravada school belongs to this phase. The third phase concerns Mahāyāna Buddhism, beginning in the late first century CE. This movement emphasizes the path of a bodhisattva and includes various schools of thought, such as Prajñāpāramitā, Mādhyamaka, Sautrāntika, Buddha-nature, and Yogācāra.
Various elements of these three phases are incorporated and/or further developed in the philosophy and worldview of the various sects of Buddhism that then emerged.
Philosophical orientation
Philosophy in ancient India was aimed mainly at spiritual liberation and had soteriological goals. In his study of the Mādhyamaka and Sautrāntika schools of Buddhist philosophy in ancient India, Peter Deller Santina writes:
For the Indian Buddhist philosophers, the teachings of Gautama Buddha were not meant to be taken on faith alone, but to be confirmed by logical analysis and inquiry (pramāṇa) of the world. The early Buddhist texts mention that a person becomes a follower of the Buddha's teachings after having pondered them over with wisdom and the gradual training also requires that a disciple "investigate" (upaparikkhati) and "scrutinize" (tuleti) the teachings. The Buddha also expected his disciples to approach him as a teacher in a critical fashion and scrutinize his actions and words, as shown in the Vīmaṃsaka Sutta.
The Buddha and early Buddhism
The Buddha
Scholarly opinion varies as to whether Gautama Buddha himself was engaged in philosophical inquiry. Siddartha Gautama (c. 5th century BCE) was a north Indian Śramaṇa (wandering ascetic), whose teachings are preserved in the Pāli Nikayas and in the Āgamas as well as in other surviving fragmentary textual collections, collectively known as the early Buddhist texts. Dating these texts is difficult, and there is disagreement on how much of this material goes back to a single religious founder. While the focus of the Buddha's teachings is about attaining the highest good of nirvāṇa, they also contain an analysis of the source of human suffering (duḥkha), the nature of personal identity (ātman), and the process of acquiring knowledge (prajña) about the world.