Sarvāstivāda-Vaibhāṣika (Sanskrit: सर्वास्तिवाद-वैभाषिक) or simply Vaibhāṣika (वैभाषिक) was an ancient Buddhist tradition of Abhidharma (scholastic Buddhist philosophy), which was very influential in North India, especially Kashmir. In various texts, they referred to their tradition as Yuktavāda (the doctrine of logic), and another name for them was Hetuvāda (the doctrine of causes). The Vaibhāṣika school was an influential subgroup of the larger Sarvāstivāda school. They were distinguished from other Sarvāstivāda sub-schools like the Sautrāntika and the "Western Masters" of Gandhara and Bactria by their orthodox adherence to the doctrines found in the Mahāvibhāṣa, from which their name is derived (Vaibhāṣa is a vṛddhi derivative of vibhāṣa, meaning "related to the vibhāṣa"). Vaibhāṣika thought significantly influenced the Buddhist philosophy of all major Mahāyāna Buddhist schools of thought and also influenced the later forms of Theravāda Abhidhamma (though to a much lesser extent).
The Sarvāstivāda tradition arose in the Mauryan Empire during the second century BCE, and was possibly founded by Kātyānīputra (c. 150 BCE). During the Kushan era, the "Great Commentary" (Mahāvibhāṣa) on Abhidharma was compiled, marking the beginning of Vaibhāṣika as a proper school of thought. This tradition was well-supported by Kanishka, and later spread throughout North India and Central Asia. It maintained its own canon of scriptures in Sanskrit, which included a seven-part Abhidharma Piṭaka collection. Vaibhāṣika remained the most influential Buddhist school in Northwest India from the first century CE until the seventh century.
