Professor M (Mysooru) Hiriyanna (7th May, 1871- 1950) was one of the greatest Samskrit thinkers and Vedantic scholars of the 19th-20th centuries. An authority on Indian Philosophy (Bhaarateeya Darshanaaha), he was well versed in both the Sanskrit classics and English literature. His distinctive perception and insight into the philosophical spirit, and his concepts and doctrines of Indian Philosophy are recognized the world over.
A contemporary of Dr S RaadhaKrishnan, Prof Hiriyanna was known for his precision, scrupulousness, and economy of expression. He was the pioneering philosopher who established the relationship between Philosophy and Aesthetics, at a time when the world believed that ” though a nation of Philosophers, The idea of the beautiful in nature did not exist in the Hindu mind!”(The philosophy of the beautiful, by William Knight).
The realization of rasa makes rather extraordinary demands on the experiencer as well as on the artist. …Rasa is, in any case, simply and solely a mental state which is the matter of cognition on the part of a perception without obstacles… (Eliot Deutsch)
A rasa (Sanskrit: रस lit. ‘juice’ or ‘essence’) denotes an essential mental state and is the dominant emotional theme of a work of art or the primary feeling that is evoked in the person that views, reads or hears such a work.
Although the concept of rasa is fundamental to many forms of Indian art including dance, music, musical theatre, cinema and literature, the treatment, interpretation, usage and actual performance of a particular rasa differs greatly between different styles and schools of abhinaya, and the huge regional differences even within one style. (from Wikipedia)
Abhinavagupta is an important source in the whole of Indian aesthetics. Also the triadic concept satyam-sundaram-shivam is quite significant.