Responses to Skepticism: Moore and Cohen

Moore's Response to Skepticism

Moore aims to counter skepticism, the idea that there's nothing we know, by offering a rigorous proof.
A rigorous proof consists of:
- Undeniable premises: obvious and certainly true.
- Logic: uses logic to reach a conclusion.
- Undeniable conclusion: beyond doubt.
Moore's proof:
- Premise: "Here is a hand" (while holding up a hand).
- Premise: "Here is another hand" (holding up the other hand).
- Conclusion: "Therefore, there are two hands."
If it's a rigorous proof, the conclusion (there are two hands) would count as knowledge.
Evaluation: The argument is valid because if the premises are true, the conclusion is also true.
Problem: Descartes would question whether the premises are undeniable, since he is skeptical about having hands.
Moore's response doesn't engage with Descartes' argument, which is based on the idea that our senses can deceive us.
Descartes doubts that sense perception gives us access to observable truths, while Moore takes it for granted.

Cohen wants to avoid skepticism by noting that all skeptical arguments share their procedure in common, and then appealing to what’s known as contextualism.
Cohen's approach: Recognizes the shared procedure of skeptical arguments and uses contextualism to counter skepticism.
Skeptical arguments share a common procedure:
- Begin with the question: Do you know that P?
- Proceed by finding something you don't know: Q.
- Note: If you know P, then you know Q.
- Conclude: You don't know P.
Example 1:
- P = "Grass is green."
- Q = "There is something green."
- Argument:
  - Premise 1: You don't know that there is something green (Descartes: senses are unreliable).
  - Premise 2: If you know that grass is green, then you know that there is something green.
  - Conclusion: You don't know that grass is green.
Example 2:
- P = "There are subatomic particles."
- Q = "There are atoms."
- Argument:
  - Premise 1: You do not know that there are atoms.
  - Premise 2: If you know that there are subatomic particles, then you know that there are atoms.
  - Conclusion: You do not know that there are subatomic particles.

Contextualism: The truth of some claims depends on the context in which they are made.
Example 1:
- Claim: "I am a professor."
- When said by the speaker, it's true.
- When said by the speaker's 7-year-old son, it's false.
Example 2:
- Claim: "This is a square" (referring to a drawn shape).
- In a kindergarten class, it might be considered a square.
- In a college geometry class, it wouldn't be considered a square (due to not having four 90-degree angles and sides of equal length).

Cohen believes that the truth of knowledge claims can depend on the context.
Example: "I know that grass is green."
- In philosophy (high standards for knowledge), you'd have to rule out possibilities like being a brain in a jar or being color blind.
- In ordinary life (lower standards), it can be true even without ruling out those possibilities.
Skeptical Argument and Contextualism:
- Argument:
  - Premise 1: You don't know that there is something green.
  - Premise 2: If you know that grass is green, then you know that there's something green.
  - Conclusion: You do not know that grass is green.
- With very high standards (philosophy), each of those premises is true.
- With low standards (ordinary life), premise one is false, so we can deny the conclusion.
Cohen's idea: For every skeptical argument, we can appeal to low standards for knowledge, deny the first premise, and deny the conclusion.
Counter-argument: What people are willing to call things is irrelevant to what things really are.
Problems with Cohen's response:
- Doesn't address what knowledge really is, only what we call knowledge.
- Skepticism concerns itself with what knowledge really is, not what we sometimes call knowledge.

Moore's response fails because it doesn't seriously engage Descartes' argument.
Cohen's response fails because it focuses on what we sometimes call knowledge rather than what knowledge really is.
To solve the problem of skepticism, we need to know what knowledge really is.