Keshav Mishra is the author of Tarkhabhasa, a work on Nyaya Vaisheshika. Kesava Misra probably lived during the 13th century CE in Mithila. The major objective of Keshav Mishra in writing Tarakabhasa was to make the Nyaya system intelligible to the average person. Following the old Nyaya tradition, he expounds in lucid language the sixteen categories of Nyaya. He avoids detailed discussions on points of controversy with other systems. He, however, discusses briefly the views of the Buddhists and the Mimamsakas on certain problems.
Keshav Mishra composed Tarka Bhasha in two parts. The first part is an exposition of the means of paramans (valid knowledge). Herein he has also discussed the Nyaya and Mimamsa views on the pramanya (validity) of knowledge. A major portion of the second part is devoted to the discussion of prameyas (the objects of knowledge), and the remaining categories are explained briefly.
To incorporate the Vaisesika categories into the Nyaya system, Keshav Mishra explains artha as an object of knowledge. According to him, artha can mean dravya (substance), guna (quality), karma (action), samanya (generality), visesha (particularly), samavaya (inherence), and abhava (non-existence). While expounding these categories, Keshav Mishra attempts to discuss elaborately certain important Vaiseshika theories such as the anu (atomic) theory, atman (being) theory, non-eternal nature of sound and others. His style is pain and the arrangement of the topics is systematic. Therefore, his work, Tarka Bhasha, has been very popular and widely read by the students of Nyaya.