Abhinavagupta (c. 940 - 1015) was one of India's great literary critics and philosophers. He was born in Kashmir and he wrote on Shaivism, aesthetics, music, and a variety of other subjects. His two famous commentaries, the Locana on the Dhvanyaloka and the Abhinavabharati on the Natyasastra engage with almost every important aspect of Indian aesthetics. In their book Santarasa (published by Bhandarkar Oriental Research Institute, Poona, 1969) authors J.L. Masson and M.V. Patwardhan write about Abhinavagupta's major contribution to Sanskrit aesthetics, the theory of rasa.