Tutorial # 16. Epistemology: What is Knowledge? Gettier:‘Is Justified True Belief Knowledge?’

Edmund Gettier: "Is Justified True Belief Knowledge?" in Analysis, v. 23.

Available at http://www.ditext.com/gettier/gettier.html

Gettier presented two examples in that:

It is possible for a person to be justified in believing a proposition that is in fact false;

and that a deduction from believing something which is flawed also allows the conditions to be satisfied yet, them not really knowing

Smith and Jones

First counterexample by Gettier:

Smith has strong evidence for a conjunctive proposition:
(a) Jones is the man who will get the job, and Jones has ten coins in his pocket.

Smith's evidence for (a) is that the president of the company told Smith that Jones would get the job. And Smith has also counted the coins in Jones' pocket.

From (a) Smith infers the following:
(b) the person who gets the job has ten coins in his pocket.
Smith accepts (b) based on proposition (a). In this case Smith is justified in believing that (b) is true.

BUT...

Unknown to Smith, he himself, and not Jones, will get the job.

And, also, unknown to Smith, he himself has ten coins in his pocket.

Proposition (b)) is then true, though proposition (a), from which Smith inferred (b), is false.

In this example, then, all of the following are true:

(i) (b) is true,

(ii) Smith believes that (b) is true,

(iii) Smith is justified in believing that (b) is true.

But does Smith really know that (b) is true?

(b) 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 (b) on a count of the coins in Jones's pocket, whom he falsely believes to be the man who will get the job.

Some usueful resources:

• Gettier problems on The Internet encyclopedia of Philosophy
  http://www.iep.utm.edu/g/gettier.htm


• Jim Pryor on Gettier. A Nice Summary of the Argument
  http://www.jimpryor.net/teaching/courses/epist/notes/gettier.html