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1.2 Gettier's counterexamples

Edmund L. Gettier's paper 'Is justified true belief knowledge?' raised doubts about the validity of the traditional definition of knowledge.8 Until the publication of this article it was, as we have just noted, unanimously accepted that knowledge is justified true belief. Gettier challenged the sufficiency of this definition. He denied that in order to have knowledge one need have justified true belief alone.
In order to show the inadequacy of the traditional definition Gettier offered two counterexamples. In both these examples Gettier has shown the absence of knowledge in the presence of justified true belief.
In the first counterexample two men Smith and Jones arc found to have applied for a job. Smith had been told by the president of the company that Jones would get the job. Further, Smith had counted the coins in Jones' pocket a few minutes ago. This gave Smith sufficient justification for believing the conjunctive proposi­tion "Jones will get the job and Jones has ten coins in his pocket". Smith derives the proposition "The man who will get the job has ten coins in his pocket" from the conjunctive proposition. How­ever, Smith gets the job, though he did not expect it. And unknown to Smith there were ten coins in his pocket. The proposition "The man who will get the job has ten coins in his pocket" becomes true and Smith is justified in believing the proposition and he actually believes it. Thus, Smith has justified true belief but he cannot be said to know, for his being right in this case is due to chance or luck.
The second counterexample runs as follows. A person called Smith (not the same person as in the first example) has ample evidence for believing the proposition (1) "Jones owns a Ford". The evidence may be that Jones has given Smith a ride while driving a Ford and he remembers that Jones had always in the past owned a Ford. Now Smith has a friend called Brown regarding whose whereabouts Smith is totally in the dark. Smith picks up three place names quite at random and constructs the following three disjunctive propositions:

1. Either Jones owns a Ford or Brown is in Boston
2. Either Jones owns a Ford or Brown is in Barcelona
3. Either Jones owns a Ford or Brown is in Brest Litovsk

All the three propositions (2), (3), and (4) are entailed by (1) and Smith knows that and comes to believe each of the proposi­tions.
Surprisingly enough, Jones does not own a Ford. The car he is seen driving is a rented car. However, quite accidentally, Brown happens to be in Barcelona. The proposition (3) thus happens to be true. Smith is justified in believing the proposition and he believes it. But he has no knowledge about it for he does not know where at present Brown is.
These two counterexamples are, however, based on three presuppositions of which the first two are mentioned by Gettier himself.9
The presuppositions are:
 (i) A person may be justified in believing a proposition which is in fact false.
(ii) If S is justified in believing a proposition p and if p entails q and S derives q from p and comes to believe q as a result of this derivation, then S is justified in believing q.
(iii) There may be false justifiers.
The reactions against Gettier took three forms :

1. One consisted in questioning the genuineness of Gettier counterexamples. They are held suspect because the presuppositions on which they are based are found to be questiona­ble. Some questioned the first presupposition, others the second, and some others the third ;
2. another in strengthening or modifying the traditional definition ;
3. and the third consisted in giving a completely new definition. .

We shall be concerned in this book only with the first two reactions and shall discuss the first reaction in this chapter.

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