Asaṅga (ca. 320-ca. 390) is regarded as the founder of the Yogācāra tradition of Mahāyāna philosophy.
His biography reports that he was born in Puruṣapura, India (present day Peshawar in Pakistan), which at that time was part of the ancient kingdom of Gandhāra.
He started practicing Buddhism probably in Mahīśāsaka School but later converted to Mahāyāna, later convincing his brother Vasubandhu to make the same move.
Together they systematized the teachings of Yogācāra, authoring the main Yogācāra commentaries and treatises.
Asaṅga spent many years in serious meditation, during which time tradition says that he often visited Tuṣita Heaven to receive teachings from Maitreya Bodhisattva.
The famous Chinese Buddhist and traveller to India Hsüan-tsang (c. 602–664) recounts:
In the great mango grove 5-6 li to the southwest of the city (Ayodhya), there is an old monastery where Asaṅga Bodhisattva received instructions and guided the common people:
At night he went up to the place of Maitreya Bodhisattva in Tuṣita Heaven to learn the Yogācāra-bhūmi-śāstra, the Mahāyāna-sūtra-alaṁkāra-śāstra, the Madhyānta-vibhāga-śāstra, etc.;
in the daytime, he lectured on the marvellous principles to a great audience.
Asaṅga’s many works include:
a) Abhidharma-samuccaya (A Compendium of Abhidharma), which presents and defines technical terms and usages, and
b) the Yogācāra-bhūmi-śāstra, extant only in Chinese translation, a text that summarizes the truly compendious Yogācāra-bhūmi (Stages of Yogic Practice), with which he is also connected as author/editor.
c) Mahāyāna-saṁgraha (Summary of the Great Vehicle)
Other commentaries are attributed to him on important Yogācāra and some Prajña-pāramitā and Madhyamaka works as well.
By far his principal work is the Mahāyāna-saṁgraha (Summary of the Great Vehicle), in which he presents the tenets of Yogācāra in clear and systematic fashion, moving step by step:
first explaining the basic notion of the storehouse consciousness (ālaya-vijñāna) and its functional relationship to the mental activities of sensing, perceiving, and thinking,
then outlining the structure of consciousness in its 3 patterns:
1) the other-dependent (dependent arising applied to the very structure of consciousness),
2) the imagined, and
3) the perfected, which is the other-dependent emptied of clinging to the imagined.
He then sketches how the Mind constructs its world;
he develops a critical philosophy of Mind that, in place of Abhidharma’s naive realism, can understand understanding, reject its imagined pattern, and—having attained the perfected state of Śūnyatā (Emptiness)—engage in other-dependent thinking and action.
Asaṅga thereby reaffirms the conventional value of theory, which had appeared to be disallowed by earlier Madhyamaka dialectic.
He treats the practices conducive to Awakening (perfections, stages, discipline, concentration, and non-imaginative wisdom) and finally turns to the abandonment of delusion and the realization of Buddhahood as the 3 bodies of Awakening.
Asaṅga’s work is a compendium of critical Yogācāra understanding of the mind.