Kavyashastra (science of poetry)

Ānandavardhana (आनन्दवर्धन) famous ninth century theorist who propounded his theory of “poetic manifestation” (dhvani or vyañjanā). Dhvani was so important to Ānandavardhana that his text, Dhvanyāloka, is named after it.—Ānandavardhana was not an unreligious man. He is known to have composed an elaborate hymn to the Goddess, called Devīśataka [Devīśatakam], or One Hundred Verses on the Goddess, which is still available, and a work called Tattvāloka, or Lamp on Reality, which has been lost, but which Abhinavagupta tells us was about metaphysics and theology. Abhinavagupta also tells us, interestingly, that Ānandavardhana wrote a sub-commentary on a famous Buddhist work, Dharmottara’s commentary on Dharmakīrti's Pramāṇaviniścya, or Determination of Authoritative Means of Knowledge.

Ānandavardhana was the author of Dhvanyāloka, or A Light on Suggestion, a work articulating the philosophy of "aesthetic suggestion". The philosopher Abhinavagupta wrote an important commentary on it, the Locana, or The Eye. Ānandavardhana is credited with creating the dhvani theory.