Gettier problem
Introduction
The Gettier problem is a philosophical question that challenges the classical definition of knowledge as justified true belief (JTB). The problem is named after American philosopher Edmund Gettier, who, in a three-page paper published in 1963, presented two cases in which someone had a true belief justified by evidence, but, intuitively, did not have knowledge.
Background
The classical definition of knowledge, dating back to Plato and his dialogues, posits that for an individual to know a proposition, the proposition has to be true, the individual has to believe the proposition, and the individual has to be justified in believing the proposition. This is often abbreviated as JTB. However, Gettier's paper, titled "Is Justified True Belief Knowledge?", challenged this definition by providing examples of situations where all three conditions (justification, truth, and belief) are met, but we would not say that the individual has knowledge.
Gettier's Cases
In his paper, Gettier presented two cases, now known as Gettier cases, that challenge the JTB definition of knowledge.
Case I
In the first case, Smith has strong evidence for the proposition "Jones owns a Ford." Based on this, Smith infers, "Either Jones owns a Ford, or Brown is in Barcelona," even though Smith has no knowledge about Brown's whereabouts. As it turns out, Jones does not own a Ford, but by sheer coincidence, Brown is indeed in Barcelona. Thus, Smith's belief that "Either Jones owns a Ford, or Brown is in Barcelona" is true and justified, but it seems incorrect to say that Smith knows "Either Jones owns a Ford, or Brown is in Barcelona," because his justification is based on a false premise.
Case II
In the second case, Smith has strong evidence that "Jones will get the job," and he also knows that "Jones has ten coins in his pocket." From this, Smith infers the proposition "The man who will get the job has ten coins in his pocket." However, it turns out that Smith, not Jones, gets the job, and Smith also happens to have ten coins in his pocket. So, the proposition "The man who will get the job has ten coins in his pocket" is true and Smith believes it, but his belief is based on incorrect reasoning.
Responses to the Gettier Problem
The Gettier problem has sparked a significant amount of debate and discussion in the field of epistemology, the study of knowledge and belief. There have been many responses to the problem, some of which attempt to revise the JTB definition of knowledge, while others propose entirely new definitions.
No False Lemmas
One response to the Gettier problem is the no false lemmas (NFL) solution, which suggests adding a fourth condition to the JTB definition of knowledge: the justification for the belief must not rely on any false premises. This solution would rule out Gettier cases because in each case, the justification for the belief relies on a false premise.
Reliabilism
Another response is reliabilism, which proposes that a belief counts as knowledge if it is produced by a reliable process. This approach shifts the focus from the justification of a belief to the reliability of the process that produced the belief. However, reliabilism faces its own set of challenges, such as defining what constitutes a reliable process and dealing with cases where a reliable process produces a false belief.
Virtue Epistemology
Virtue epistemology is another approach that has been proposed in response to the Gettier problem. This approach suggests that knowledge is a belief that arises from the exercise of intellectual virtues, such as good reasoning, insight, or understanding. Virtue epistemologists argue that in Gettier cases, the individual lacks knowledge because they are not exercising these intellectual virtues.
Conclusion
The Gettier problem has had a profound impact on the field of epistemology, prompting philosophers to reevaluate the classical definition of knowledge and propose new definitions. Despite over half a century of debate, there is still no consensus on how to solve the problem, making it one of the most enduring questions in philosophy.