4.+Epistemology+--+Pollock

Introduction to Skepticism and Knowledge

  • J. Pollock introduces the thought experiment "A brain in a vat" which challenges our understanding of knowledge.

Thought Experiment

  • Stipulation regarding Harry as a BIV (Brain in a Vat) vs. Mike as an embodied person reveals critical questions about knowledge.

  • Key questions:

    • Can Harry know he is walking, showering, etc.?

    • How about Mike, when he believes the milk is on the counter or has just finished dinner?

    • Would volunteering for the procedure clear Mike’s doubts?

    • What tests can one perform to distinguish whether they are a BIV?

  • Discussion prompts for evaluating one's own knowledge about the reality.

Classical Analysis of Knowledge

  • Classical conditions for knowing that a proposition (p) is true:

    1. S believes that p.

    2. p is true.

    3. S is adequately justified in believing p.

  • Harry lacks knowledge of having hands due to false belief.

  • For Mike, adequacy of justification can be questioned:

    • He may have perceptual evidence but is unable to exclude the possibility of being a BIV.

  • The exclusion principle:

    • Adequately justified beliefs must rule out all possibilities where p is false, making BIV a critical counterexample.

Examining Knowledge and Error

  • Ruling out possibilities of error is essential in affirming knowledge.

  • Skeptical scenarios increase an individual's doubt about knowledge claims:

    • Possible errors include dreaming, BIV, or deception by an evil demon.

  • Knowledge demands more stringent evidence than typical everyday situations.

Error Possibilities Exercise

  • Identify possible error scenarios for various beliefs:

    • You are a TAMUCC student.

    • Your neighbor Jose is mowing the lawn.

    • Other humans typically feel pain when sustaining a serious injury.

    • You have a brain.

    • You are in pain right now.

Argument for Skepticism about External World

  • Knowledge of the external world hinges on the ability to rule out error.

  • Since this is impossible with our evidence, knowledge of the external world cannot be claimed.

Infinite Regress of Reasons

  • Examines chains of justification:

    • If a basic belief lacks justification, it undermines the entire chain.

  • Such chains may continue infinitely, creating a predicament for knowledge claims.

Example of Justification

  • Illustrates practical reasoning:

    • Belief: "I know Tim won’t be in town this Friday."

    • Justification involves several layers:

      • Tim will be in NYC.

      • Tim has a job interview there.

      • Overheard information adds to credibility.

Structure of Knowledge and Response to Skepticism

  • Presents an argument for skepticism:

    1. Knowledge requires an infinite chain of justifiers.

    2. Finite beings cannot establish such justifiers.

    3. Thus, knowledge is deemed impossible.

  • Strategies to avoid skepticism:

    • Foundationalism: Ends of reasoning chains with basic beliefs.

      • Supported by Descartes, who posits foundational beliefs underpin all knowledge claims.

    • Coherentism: Circular reasoning considered harmless and justifiable.