Why I hate the "Gettier Problem."


I’m sorry. You may think less of me for this confession, but I do not believe that the Gettier problem poses a problem for the Justified True Belief (JTB) definition of knowledge. This is a largely accepted theory in philosophy but I just don’t buy it. Therefore, this article will be defending JTB and how Gettier fails to criticise it because he cannot provide a realistic premise that counts as knowledge under JTB but we would hesitate to classify as knowledge.

What does Gettier argue against?

The idea Gettier rejects within the problem is that knowledge is justified true belief. This idea was created by Plato in the Meno. Plato initially starts with the similarities between true belief and knowledge. He uses the example of two guides trying to get you to point B. He argues that the guide who has never been to point B before but still gets you there through true belief is just as good as the guide who knows where point B is and takes you there. However, Plato argues that this is not enough to claim knowledge. He argued that ideas need to be “tethered down”. That is to say, there needs to be something which stops true beliefs from changing. This is in the form of justification. An example of this is a court. A judge could believe someone is guilty and this would be true. However, we would not class this as knowledge. However, if the criminal’s finger prints are all over the scene and he is covered  in blood then we are entitled to grant the judge knowledge. Therefore, justification, truth and belief are required for knowledge.

This can be summarised in the following way;

S believes p.
P is true
S has justification for p.



How does he do it?

Gettier disagrees with the definition of knowledge above because he argues that these are not sufficient for a complete definition of knowledge. This is because of the vagueness of term “justification” and that some justification can not be used due to wider circumstances. This is demonstrated in the cases below (these are directly taken from Gettier’s Analysis, Vol 23, No.6 p121-123)

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

(d) 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 :

(e) 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.

Case 11: Let us suppose that Smith has strong evidence for the following proposition :

(f) Jones owns a Ford.

Smith’s evidence might be that Jones has at all times in the past within Smith’s memory owned a car, and always a Ford, and that Jones has just offered Smith a ride while driving a Ford. Let us imagine, now, that Smith has another friend, Brown, of whose whereabouts he is totally ignorant. Smith selects three place-names quite at random, and constructs the following three propositions :

(g) Either Jones owns a Ford, or Brown is in Boston;

(h) Either Jones owns a Ford, or Brown is in Barcelona;

(i) Either Jones owns a Ford, or Brown is in Brest-Litovsk.

Each of these propositions is entailed by (f). Imagine that Smith realizes the entailment of each of these propositions he has constructed by (f), and proceeds to accept (g), (h), and (i) on the basis of (f). Smith has correctly inferred (g), (h), and (i) from a proposition for which he has strong evidence. Smith is therefore completely justified in believing each of these three propositions. Smith, of course, has no idea where Brown is.

But imagine now that two further conditions hold. First, Jones does not own a Ford, but is at present driving a rented car. And secondly, by the sheerest coincidence, and entirely unknown to Smith, the place mentioned in proposition (h) happens really to be the place where Brown is. If these two conditions hold then Smith does not know that (h) is true, even though (i) (h) is true, (ii) Smith does believe that (h) is true, and (iii) Smith is justified in believing that (h) is true. These two examples show that definition (a) does not state a sufficient condition for someone’s knowing a given proposition. The same cases, with appropriate changes, will suffice to show that neither definition (b) nor definition (c) do so either.

Why is this wrong?

Case 1

We can’t substitute JTB for deduction.

Smith is told Jones will get the job by the interviewer because he has 10 coins in his pocket. The knowledge “The person who gets the job has 10 coins in his pocket.” is deduced from this. However, this leap is not justified. We can’t know this for certain without there being sufficient justification for this within the world. In fact, it can be argued that the premise above doesn’t even match JTB because deduction is not a method of justification. We need to treat the piece of knowledge above on its own and match it against the criteria of JTB . Therefore, Gettier doesn’t even provide a challenge to JTB because it does not live up to the JTB criteria, so isn’t classed as knowledge anyway.

The situation is only theoretical.
The effectiveness of Gettier is limited due to its lack of practicality within the world. There will never be a situation where you know you will get a job because you have 10 coins in your pocket. An interviewer will never tell you that someone else will definitely get the job. This makes it difficult for Gettier’s problem to make a transfer from the hypothetical world to the real world. Therefore, on this basis, Gettier doesn’t criticise JTB in a practical sense and therefore his argument fails to challenge that K=JTB

Case 2

He does not have strong evidence
Gettier claims that Smith has strong evidence for Jones owning a Ford. However, this doesn’t seem the case. There are multiple reasons for this. Firstly, the definition of “own” does not mean what he is driving now. He doesn’t own the rented car. Therefore, he could still own the Ford. Secondly, clearly Jones and Smith know each other in order to know that Jones drives a Ford. If we makes this assumption then surely Smith would know by this point that Jones had got rid of his Ford, or crashed it and was driving a rented car. This has two consequences. Firstly, it can be argued that the JTB conditions are not fully full-filled due to Smith clearly not having “strong justification”. Therefore, this poses no threat to JTB as it is not classed as knowledge anyway and so poses no problem. Secondly, this underlines the point above that Gettier fails to provide a problem which can be posed in reality. Therefore, this reduces Gettier’s ability to provide a fatal challenge to JTB.

Two separate pieces of information.
Yet again, we have to consider what is counted as a piece of knowledge. It can be argued that the statements above can be separated into two pieces of knowledge. Firstly, Jones driving a Ford, which we have looked into above, and secondly, the premises on where his other friend is. If we take this second premise, then we can see that this can’t be classed as knowledge under JTB. This is because he has randomly plucked places out of thin air. We can argue that he firstly has no rational justification for this, and secondly he doesn’t truly believe it because he picked the names from random. Therefore, under JTB this does not class as a piece of knowledge and poses no threat to JTB.

To Conclude
To conclude, Gettier’s cases both fail. This is because he can not prove that there are instances of justified true belief which we would not class as knowledge. This is mainly due to his definition of what is a piece of knowledge and how these live up to JTB. This is because he attempts to merge pieces of information in order to meet demands of JTB but make sure the premise doesn’t count as information. As demonstrated above, this attempt fails.

Published by Philosopher Ad Absurdum

MA Philosophy of Mind and Cognitive Science at the University of Birmingham; First Class BA Philosophy and History from the University of Southampton.

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