PHILOSOPHY - Epistemology: Analyzing Knowledge #2 (No-False-Lemma and No-Defeater Approaches)

TL;DR

Explores two approaches to refine justified true belief analysis.

Transcript

my name is Jennifer Nagel I teach philosophy at the University of Toronto and today I want to talk to you about analyzing knowledge this video looks at two different ways to do this both of which are modifications of the classical analysis of knowledge as justified true belief the pure JTB analysis of knowledge is not very popular now it's widely a... Read More

Key Insights

• The classical analysis of knowledge as justified true belief (JTB) is insufficient due to counterexamples like Gettier cases.
• Michael Clark's 'no false belief' approach suggests eliminating reliance on false beliefs to refine JTB, but it can be overly strict.
• Clark's theory may exclude valid knowledge cases where false beliefs exist but do not undermine the overall evidence.
• The 'no defeater' analysis by Lehrer and Paxson introduces the concept of undefeated justified true belief to address Gettier problems.
• Basic knowledge is self-evident and doesn't rely on justifying statements, while non-basic knowledge requires supporting evidence.
• The presence of a defeater, which undermines justification, is crucial in analyzing knowledge in non-basic cases.
• Defeaters can themselves be defeated, restoring justification, but the theory struggles with defining which defeaters are ultimately undefeated.
• Challenges for the 'no defeater' theory include explaining justification without circular reasoning and addressing cases like the desert mirage.

Questions & Answers

Q: What is the main issue with the classical analysis of knowledge as justified true belief?

The main issue with the classical analysis of knowledge as justified true belief (JTB) is the existence of counterexamples known as Gettier cases. These cases demonstrate situations where an individual can have a justified true belief without actually possessing knowledge, highlighting the insufficiency of JTB as a comprehensive analysis of knowledge.

Q: How does Michael Clark propose to refine the justified true belief analysis?

Michael Clark proposes to refine the justified true belief analysis by introducing the 'no false belief' approach. This method suggests that knowledge can be achieved if one eliminates reliance on false beliefs in the process of forming a justified true belief. However, this approach is criticized for being too strict, potentially excluding valid cases where false beliefs do not undermine the overall evidence.

Q: What is the concept of 'defeaters' in Lehrer and Paxson's analysis?

In Lehrer and Paxson's analysis, 'defeaters' are factors that undermine the justification of a belief, preventing it from being classified as knowledge. The concept is crucial in their 'no defeater' approach, which posits that knowledge consists of undefeated justified true belief. A defeater can itself be defeated, restoring justification, but the theory faces challenges in determining which defeaters are ultimately undefeated.

Q: What are the two kinds of knowledge according to Lehrer and Paxson?

According to Lehrer and Paxson, knowledge is divided into two kinds: basic and non-basic. Basic knowledge is self-evident and does not rely on any justifying statements, such as knowing you have a headache. Non-basic knowledge, on the other hand, requires supporting evidence and is subject to the influence of defeaters, which can undermine its justification.

Q: Why is Clark's 'no false belief' theory considered too strict?

Clark's 'no false belief' theory is considered too strict because it excludes cases where individuals can possess knowledge despite some false beliefs. For example, a detective with overwhelming evidence of a crime may still be considered not to know the culprit if even one piece of evidence is false, despite the strength of the overall evidence supporting their belief.

Q: What challenge does the 'no defeater' theory face with basic knowledge?

The 'no defeater' theory faces a challenge with basic knowledge in defining what it means to have a true belief with complete justification without resorting to circular reasoning. The theory struggles to explain the concept of justification without using the notion of knowledge itself, particularly in cases where basic knowledge is supposed to be self-evident and not reliant on justifying statements.

Q: How does the desert mirage case challenge the 'no defeater' theory?

The desert mirage case challenges the 'no defeater' theory by presenting a scenario where a belief is true and doesn't seem to rely on any justifying statement, potentially classifying it as basic knowledge. However, if the traveler doesn't actually know there's water despite the true belief, it raises issues for the theory's ability to handle such cases, questioning whether the classification of knowledge is accurate.

Q: What is a potential problem with determining which defeaters are ultimately undefeated?

A potential problem with determining which defeaters are ultimately undefeated lies in the complexity of evidence and its interpretation. In Gettier cases, where the belief is ultimately true, any evidence against it should be considered misleading. However, the theory struggles to clearly define which defeaters should count as ultimately undefeated, complicating the analysis of knowledge and justification.

Summary & Key Takeaways

• The video examines two modifications to the classical analysis of knowledge as justified true belief: the 'no false lemma' approach by Michael Clark and the 'no undefeated defeaters' approach by Keith Lehrer and Thomas Paxson. Both aim to resolve issues raised by Gettier cases, but face their own challenges.

• Clark's 'no false belief' approach attempts to refine JTB by eliminating reliance on false beliefs, but it is criticized for being too strict, potentially excluding cases where knowledge is valid despite some false beliefs. Lehrer and Paxson's 'no defeater' approach introduces the concept of undefeated justified true belief.

• The 'no defeater' theory divides knowledge into basic and non-basic types, with non-basic knowledge requiring supporting evidence. It addresses Gettier problems by considering the influence of defeaters on justification. However, it faces challenges in defining justification without circular reasoning and handling cases like the desert mirage.