In the 10th-11th centuries C.E., certain schools of Indian Buddhist philosophical thought held that any entity had a total life span of only one moment (ksanabhanga). This had serious philosophical ramifications for theories of causality, moral responsibility, and personal salvation. On the Buddhist doctrine, the human being who does the act cannot be the same person who reaps the reward or punishment.

The primary critic of this doctrine was the Hindu logician Udayana who critically examined the Buddhist position in a monumental work, the Atmatattvaviveka. Principal aims of this dissertation are to provide an accurate account of Udayana's polemic against the Buddhist doctrine of impermanence and to present Udayana in a proper historical perspective. There has been a need to reexamine certain philosophical concepts discussed in the secondary literature due to their prevailing misinterpretations; cases in point are the Samkhyan term 'purusartha' (for purusa's objective) and the Ny aya-Vaisesika term 'parimandala' (measure of an atom).

The four main schools of Buddhist philosophy (the Vaibhasika, Sautrantika, Madhyamika, and Yogacara) had metaphysical accretions that the Buddha studiously avoided. Some of their teachings Udayana identified as being similar to his own. For instance, the doctrine of svabhava implies an entity which is capable of having a self-nature. This entity, Udayana declared, is none other than the soul.

In arguing against the Buddhist position, Udayana has demonstrated that if the doctrine of momentary existence is accepted, then one cannot properly speak of universals and particulars, but only of individuals. Neither can one legitimately speak of an entity having an abiding self-nature (atman), nor of causality; the problem of memory, the manner of definition of individuals (apoha), and the ways in which one decides whether or not error has been committed are all incapable of rectification.

The Nyaya-Vaisesika argument is that an object need exist for at least three moments: one each of creation, endurance, and destruction. This has certain parallels to later Buddhism, yet remains distinctly different.

A translation of the Ksanabhanga portion of the Atmatattvaviveka and a critical edition of the text form the appendices.