Sentient beings (Buddhism)
In Buddhism, sentient beings are beings with consciousness, sentience, or in some contexts life itself. Sentient beings are composed of the five aggregates, or skandhas: matter, sensation, perception, mental formations and consciousness. In the Samyutta Nikaya, the Buddha is recorded as saying that "just as the word 'chariot' exists on the basis of the aggregation of parts, even so the concept of 'being' exists when the five aggregates are available." While distinctions in usage and potential subdivisions or classes of sentient beings vary from one school, teacher, or thinker to another, it principally refers to beings in contrast with buddhahood. That is, sentient beings are characteristically not enlightened, and are thus confined to the death, rebirth, and dukkha (suffering) characteristic of saṃsāra.
However, Mahayana Buddhism simultaneously teaches that sentient beings also contain Buddha-nature—the intrinsic potential to transcend the conditions of saṃsāra and attain enlightenment, thereby obtaining Buddhahood.
Those who greatly enlighten illusion are Buddhas; those who are greatly deluded about enlightenment are sentient beings."
In Mahayana Buddhism, it is to sentient beings that the Bodhisattva vow of compassion is pledged. Furthermore, and particularly in Tibetan Buddhism and Japanese Buddhism, all beings (including plant life and even inanimate objects or entities considered "spiritual" or "metaphysical" by conventional Western thought) are or may be considered sentient beings.
Getz (2004: p. 760) provides a generalist Western Buddhist encyclopedic definition:
Sentient beings is a term used to designate the totality of living, conscious beings that constitute the object and audience of Buddhist teaching. Translating various Sanskrit terms (jantu, bahu jana, jagat, sattva), sentient beings conventionally refers to the mass of living things subject to illusion, suffering, and rebirth (Saṃsāra). Less frequently, sentient beings as a class broadly encompasses all beings possessing consciousness, including Buddhas and Bodhisattvas.
Early scriptures in the Pāli Canon and the conventions of the Tibetan Bhavacakra classify sentient beings into five categories—divinities, humans, animals, tormented spirits, and denizens of hell—although sometimes the classification adds another category of beings called asuras between divinities and humans.