Their story
Dignāga is usually placed around 480–540 CE. Tradition says he was born to a brahmin family near Kāñcī in South India, became a monk, and studied under Vasubandhu, though the connection may be one of ideas rather than of teacher and pupil.
His major work, the Pramāṇasamuccaya, or 'Compendium on the Means of Knowledge', argued that there are only two valid means of knowledge: perception, which grasps the unique particular, and inference, which works through concepts.
He is said to have travelled widely, debating with brahmin and Buddhist opponents, and to have taught at Nālandā.
The world they lived in
Indian philosophers of every school were developing theories of valid knowledge (pramāṇa) and formal debate. To hold one's own in public debate, Buddhists needed a logic that opponents would accept.
Their contribution
He gave Buddhism a rigorous logic and theory of knowledge, including the theory of 'exclusion' (apoha), which explains how words and concepts work without real universals. His rules for valid argument became a shared language for Indian philosophy.
Teachings and works
Pramāṇasamuccaya (Compendium on the Means of Knowledge)
Ālambanaparīkṣā (Investigation of the Object of Awareness)
Nyāyamukha (Introduction to Logic)
Preserved in Chinese.
Related teachings
Their legacy
His work was developed by Dharmakīrti into the dominant form of Buddhist epistemology, studied in Tibetan monasteries to this day. Chinese and Japanese scholars studied his logic as 'the science of reasons' (yinming).
History and tradition
What history can establish
His works are accepted, though several survive only in Tibetan or Chinese translation. Details of his life come from much later Tibetan histories.
What Buddhist tradition remembers
Tibetan tradition counts him among the 'Six Ornaments' of India, the great masters of Buddhist learning, and tells that the bodhisattva Mañjuśrī appeared to encourage him when he despaired of finishing his work.
