Gettier and the failure of justified true belief

Edmund Gettier is Professor Emeritus at the University of Massachusetts, Amherst. He owes his reputation to a single short (only three pages!) paper published in 1963 ‘Is Justified True Belief Knowledge?’ It seemed to many to refute the traditional longstanding and otherwise attractive analysis of knowledge. It stimulated a renewed effort, still ongoing, to clarify exactly what knowledge comprises. A satirical website describes Gettier thus:

Gettier has the highest fame-to-effort ratio of any philosopher ever. His seventeen word paper, written entirely in crayon, has been referenced over two and a half trillion times in the last two days. It is interesting to note that Gettier almost didn't get his current lecturing position as the candidate who went before him, a Mr. Jones, was very promising indeed. However, the interviewers took pity on Gettier when he revealed his dire financial situation, having only ten coins to his name. Gettier currently lives in Boston and owns a Ford.

The traditional picture is that knowledge is justified true belief, or as Gettier summarises it:

S knows that P if and only if:

P is true,

S believes that P, and

S is justified in believing that P

His paper attacks this by setting out two cases which fit the analysis of knowledge but which, intuitively, fail to count as knowledge. Here’s one of them.

Case 1

Suppose that Smith and Jones have applied for a certain job. And suppose that Smith has strong evidence for the following conjunctive proposition:

Jones is the man who will get the job, and Jones has ten coins in his pocket.

Smith's evidence for (d) might be that the president of the company assured him that Jones would in the end be selected, and that he, Smith, had counted the coins in Jones's pocket ten minutes ago. Proposition (d) entails:

The man who will get the job has ten coins in his pocket.

Let us suppose that Smith sees the entailment from (d) to (e), and accepts (e) on the grounds of (d), for which he has strong evidence. In this case, Smith is clearly justified in believing that (e) is true.

But imagine, further, that unknown to Smith, he himself, not Jones, will get the job. And, also, unknown to Smith, he himself has ten coins in his pocket. Proposition (e) is then true, though proposition (d), from which Smith inferred (e), is false. In our example, then, all of the following are true: (i) (e) is true, (ii) Smith believes that (e) is true, and (iii) Smith is justified in believing that (e) is true. But it is equally clear that Smith does not know that (e) is true; for (e) is true in virtue of the number of coins in Smith's pocket, while Smith does not know how many coins are in Smith's pocket, and bases his belief in (e) on a count of the coins in Jones's pocket, whom he falsely believes to be the man who will get the job.

So the first question is: does this really undermine the traditional analysis?

Second, if it does, what is the problem with the traditional analysis? Could it be repaired?

One response, next week, is to replace the traditional analysis with reliabilism. Another is Nozick's four condition model which we also consider this week.

Reading

- Gettier, E. (1963) 'Is Justified True Belief Knowledge?' Analysis 23: 121-123

Nozick, R. (2010) 'Knowledge and scepticism' Sosa et al (eds) (2010) Epistemology: an anthology, Oxford Blackwell. Read as far as p269 'sins of credulity'. (A crude pdf of the text can be found here.)