Nyayasara is a work on the Nyaya system of philosophy by Bhasavajna (9th century CE). It is the only work composed by Bhasavajna, and he added a commentary on this work later. Historians of Nyaya philosophy list as many as eight commentaries, of which three are available in print. His commentary was called Bhusana, and it was discovered only in the latter half of the 20th century. The author is popularly referred to as Bhusanakara after his commentary. He had a leaning toward Yoga philosophy and the Pasupata religion. The work consists of three paricchedas – pratyaksha, anumana and sabda. He admits three sources of knowledge only and excludes upamana.
He accepts the onset of bliss in moksha; it is not just cessation of pain. He prescribes kriya yoga for realization and a state of abhinati (detachment). He emphasizes bhakti. He accepts three kleshas only – avidya, asmita and moha, raga and dvesha are subsumed under moha.