Buddha nature ［仏性］ ( buddha-dhātu or buddha-gotra; busshō): The internal cause or potential for attaining Buddhahood. The Sanskrit word dhātu means root, base, foundation, ground, or cause, and gotra means family, lineage, basis, source, cause, or seed. Mahayana Buddhism generally holds that all people possess the innate Buddha nature, though its existence is obscured by illusions and evil karma. The Nirvana Sutra is especially famous for the phrase “All living beings alike possess the Buddha nature.”
The history of Buddhism has witnessed doctrinal arguments concerning the Buddha nature, especially with regard to whether all people possess it. The Dharma Characteristics (Chin Fa-hsiang; Hossō) school, for instance, teaches the doctrine of the five natures, which classifies all people into five groups by their inborn capacities: those destined to be bodhisattvas, those destined as cause-awakened ones, those destined as voice-hearers, an indeterminate group, and those who can neither become bodhisattvas nor attain the enlightenment of voice-hearers or cause-awakened ones. Of these, only those destined to be bodhisattvas and some among the indeterminate group can attain Buddhahood. In contrast, the T’ien-t’ai (Chin; Tendai) school, which is based on the Lotus Sutra, holds that all people are endowed with the three inherent potentials of the Buddha nature—the innate Buddha nature, the wisdom to perceive it, and the deeds to develop it—and therefore can attain enlightenment.