Philosophers (viz. Ayer, Chisholm, Woozley) however have tried to defend the traditional thesis by referring to the necessary conditions of knowledge. The three conditions are the belief-condition, the justification-condition, and the truth-condition of knowledge. It is undeniable that considered separately each of the conditions is apparently trivial, and they are considered to be jointly exhaustive conditions of empirical/scientific knowledge. This position has been threatened by theGettier counter-example.Gettier example points out that it is possible that there can be a belief whose falsity is overshadowed by an apparent but justifiable truth. In order to bridge this gap between justification and truth, Lehrer states a fourth condition which is as follows: If S knows that p, then S is completely justified in accepting that p in some way that does not depend on any false statement. There are arguments to show that the conditions of knowledge are indispensable though they are interdependent.It is the inevitability of the much-discussed conditions that might have provoked scholar like Fred Dretske who has written an article on the fiftieth anniversary of Gettier’s famous paper.

According to Dretske, Gettier counter-example works on two assumptions:

 1) The justification one needs to know that p is true is a justification one can have for a false proposition,

2) If you are justified in believing p, and you know that p entails q and accept q as a result, you are justified in believing q.

Drteske’s conclusion is, assumption 1 is to be rejected if we accept assumption 2. And though he rejects principles (called closure) like assumption 2, in Gettier-case, it is a better option to reject assumption 1. The reason is, the Gettier-case teaches that the kind of justification one needs to know is not the kind one can have for a false proposition. Dretske’s exposition bears the mark of a brilliant logical structure.But I have some reservations regarding the content of his argument. My observation may be expressed in two levels. The worry centres round the relation between the two assumptions and the second one focuses on the question of accepting any or both the assumptions in case we reformulate the traditional definition of knowledge. It may be shown that these assumptions are found more in disharmony than in mutual consistence.Secondly, with the help of examples it may be shown that once the counter-example successfully hits the target, we get the Gettier-proof justification which should be adequate enough for the withering away of these assumptions. There are at least two defensible issues in Dretske’s account: Firstly his rejection of closure principle, and, secondly the rejection of indiscriminate description of justification.

Professor Indrani Sanyal is professor of Philosophy in the Department of Philosophy, Calcutta University, Kolkata. Her specialization and area of research interest are Western Logic (including Epistemic Logic, Imperative Logic, Paraconsistent Logic) Epistemology, Philosophy of Language, Analytic Philosophy. She has published several research papers in these areas and a book titled The Web of Belief (Allied Publisher: 2006) and edited a volume titled Bisuddha Prajnar Bichar (Burdhwan University Press: 2009). Apart from her philosophical research, Professor Sanyal is also a poet and her works are Brahmakamal (Atayeb Prakashani) and Japoner Kotha (Kanyakumari Prokashan), Kolkata, India.