Skepticism and Knowledge (Video Notes)

Vocabulary flashcards covering major concepts from the lecture notes on skepticism, doubt, knowledge theories, and related thought experiments.

Radical skepticism

Philosophical claim that knowledge about the external world (objects, other minds, etc.) is impossible; broad doubt beyond ordinary skepticism.

Solipsism

The view that only one’s own mind exists and there might be no knowable external world.

Matrix / Brain in a Vat (BIV)

Thought experiments suggesting our experiences could be illusionary, casting doubt on knowledge of the external world.

Evil demon (Descartes)

Descartes’ hypothetical deceiver who could completely mislead us about reality to doubt all beliefs.

Four skepticism questions

The four guiding questions: whether to engage in radical doubt, whether illusion cases prove we don’t know, whether radical doubt is coherent, and appearance vs. reality.

Foundationalism

Epistemological view that knowledge rests on secure, self-evident foundations from which all other beliefs are justified.

Self-evidence

Certainty of the thinking subject; a presumed indubitable starting point for knowledge.

Non-deceiving God

Cartesian hypothesis that God is not a deceiver, which would rescue knowledge of the external world.

Sense data

Immediate, raw data of perception; what sense experiences seem to present to us.

Descartes’ strategy

Secure self and seemings, then argue for a non-deceiving God to infer the external world.

Logical Positivists’ strategy

Secure sense data and construct the world through logical relations defined in terms of sense data.

Seemings

Appearances or sensory states that seem to be the case, serving as data for justification.

Verificationism/verification principle

Meaning or truth of statements is tied to empirical verification; central to early Logical Positivism.

Gettier problem

Challenge to the idea that justified true belief is sufficient for knowledge, via cases of luck or faulty justification.

Justified True Belief (JTB)

Traditional account of knowledge: a belief that is true and adequately justified.

Reliabilism

Theory that knowledge is true belief produced by a reliable belief-forming process.

Brain-in-a-Vat (BIV)

A brain kept alive and stimulated to have experiences; raises skepticism about knowledge of the external world.

Aboutness/Intentionality

Feature of mental states to be about or refer to something (their objects or contents).

Twin Earth

Putnam’s thought experiment where terms refer to different substances in Earth vs Twin Earth, showing reference depends on external facts.

Putnam’s reference/aboutness (Putnam’s TA context)

Idea that reference hinges on causal/history links to the world, not mere resemblance; challenges purely internal fits.

Semantic Transcendental Argument (Semantic TA)

Argument using the meaning of our terms to show that skepticism presupposes false semantic commitments; aims to defeat skeptical conclusions.

Bouwsma’s perfect deception

Argument that perfectly coherent deception is impossible; thick (perfect) illusions undermine genuine reference and meaning.

Inductive generalization skepticism

Skepticism about the justification of generalizing from observed cases to unobserved cases.