These meditations were seen as being supported by the other elements of the eightfold path, such as the practice of ethics, right exertion, sense restraint and right view. Two mental qualities are said to be indispensable for yogic practice in Buddhism, samatha (calm, stability) and vipassanā (insight, clear seeing). Samatha is the quality of a stable, relaxed and calm mind. It is also associated with samadhi (mental unification, focus) and dhyana (a state of meditative absorption). Vipassanā meanwhile, is a kind of insight or penetrative understanding into the true nature of phenomena. It is also defined as "seeing things as they truly are" (yathābhūtaṃ darśanam). The true nature of things is defined and explained in different ways, but an important and unique feature of classical Buddhism is its understanding of all phenomena (dhammas) as being empty of a self (atman) or inherent essence, a doctrine termed Anatta ("not-self") and Śūnyatā (emptiness). This is in sharp contrast with most other Indian traditions, whose goals are founded either on the idea of an individual soul (atman, jiva, purusha) or a universal monistic consciousness ( Brahman). Vipassanā also requires an understanding of suffering or dukkha (and thus the four noble truths), impermanence (anicca) and interdependent origination.
The hymns in Book 2 of the Shvetashvatara Upanishad, another late first millennium BCE text, states a procedure in which the body is held in upright posture, the breath is restrained and mind is meditatively focussed, preferably inside a cave or a place that is simple, plain, of silence or gently flowing water, with no noises nor harsh winds.
^ The Pāli and Sanskrit word bhāvanā literally means "development" as in "mental development." For the association of this term with "meditation," see Epstein (1995), p. 105; and, Fischer-Schreiber et al. (1991), p. 20. As an example from a well-known discourse of the Pali Canon, in "The Greater Exhortation to Rahula" (Maha-Rahulovada Sutta, MN 62), Ven. Sariputta tells Ven. Rahula (in Pali, based on VRI, n.d.): ānāpānassatiṃ, rāhula, bhāvanaṃ bhāvehi. Thanissaro (2006) translates this as: "Rahula, develop the meditation [bhāvana] of mindfulness of in-&-out breathing." (Square-bracketed Pali word included based on Thanissaro, 2006, end note.)
During the Gupta period (4th to 5th centuries), a movement of northern Mahāyāna Buddhism termed Yogācāra began to be systematized with the writings of the Buddhist scholars Asanga and Vasubandhu. Yogācāra Buddhism received the name as it provided a "yoga," a systematic framework for engaging in the practices that lead through the path of the bodhisattva towards awakening and full Buddhahood. Its teachings can be found in the comprehensive and encyclopedic work, the Yogācārabhūmi-Śāstra (Treatise on the Foundation for Yoga Practitioners), which was also translated into Tibetan and Chinese and thus exerted a profound influence on the East Asian Buddhist and Tibetan Buddhist traditions. According to Mallinson and Singleton, the study of Yogācāra Buddhism is essential for the understanding of yoga's early history, and its teachings influenced the text of the Pātañjalayogaśāstra.