The Buddhist Philosophy attracts special attention of the scholars for its unique ideas and opinions. One is always fascinated to see, how great thinkers have developed the ethical teachings of Lord Buddha in the form of many logical doctrines. Ratnakirti, the disciple of Jnanasrimitra, has written many philosophical essays to save and establish the Buddhist position. The work 'Ksanabhangasiddhi' of Ratnakirti is one of the most important work on Buddhist Theory and it was edited for the first time by Prof. Harprasad Shastri in 'Six Buddhist Nyaya Tracts'. In this, Ratnakirti has tried to establish the theory of momentariness by the method of agreement (anvaya) and difference (vyatireka). He has established the syllogism, 'whatever is existent, is momentary like a pot' as advanced by his predecessors to prove the theory of momentariness and concludes that it is not at all fallacious.