Problems of knowledge

The view that we know far less than we think — maybe nothing for certain; it questions whether real knowledge is possible.

Throw out every belief that could possibly be false, to find a rock-solid foundation nothing can shake.

You can't prove you're not dreaming right now, so your senses can't give you certainty about the world.

An all-powerful deceiver who could fake even maths — so everything, not just the senses, can be doubted.

Even total doubt needs a thinker to be deceived; if you're thinking, you exist — the one belief no demon can fake away.

He proves he exists as a thinker, but getting back out to a real world and reliable senses is the hard, unfinished part.

Maybe not — many say knowledge is strong justified belief, not a 100% guarantee, or almost nothing would count as known.

Meet the bar (find one certain thing and rebuild — Descartes) or lower the bar (knowledge = strong reasons, not certainty).

Knowledge = justified true belief: you believe it, it's true, and you have good reasons for it.

You can have a justified true belief that's true only by luck — so JTB isn't enough for knowledge.

You read 3:00 off a reliable clock and it really is 3:00 — but the clock stopped 12 hours ago, so you're right only by luck.

All three JTB ingredients are there, but the truth came by luck, not because your reason tracked it.

Roughly 'no luck' / reliable reasons — you must reach the truth non-accidentally. But it's hard to define exactly.

Belief: you think it's true. Truth: it really is. Justification: you have good reasons, not a lucky guess.

Every proposed fourth ingredient meets a new Gettier-style counter-case — after 60 years there's no agreed patch.

Knowledge may not be captured by a tidy list of ingredients — right-by-luck keeps slipping through the recipe.

The view that we perceive the real world directly, as it is — you see the mug itself, no middle step.

Since appearances can differ from reality (a straight stick looks bent), what we see is an appearance, not the thing itself.

A real world exists, but we only ever see the mental images it causes — like watching the world on a screen.

If you only ever see the images, you can never step outside to check they match the real world.

Reality is ultimately mental: only images, no material world behind them — 'to be is to be perceived'.

Berkeley's slogan: a thing exists as a bundle of experiences; unperceived, it needs God to keep existing.

Direct realism (see the world) → representative realism (see images of a world) → idealism (only images, no world behind).

Direct: illusions. Representative: stuck behind the screen. Idealism: the world vanishes when unperceived (Berkeley uses God).

Every reason needs a further reason, with no obvious end — so justification seems to need an endless, uncompletable chain.

Some 'basic' beliefs are justified on their own and support the rest — stopping the regress at bedrock.

Beliefs are justified by fitting together in a supporting web, not by resting on a base — the regress becomes a loop.

Foundationalism = a building on bedrock (basic beliefs). Coherentism = a web where beliefs hold each other up.

Internal: your reasons must be available to you. External: a reliable process can justify even if you can't state why.

An external view: a belief is justified if it comes from a reliable, truth-tracking process — no chain of stated reasons needed.

The stopped clock fails because it wasn't a reliable process — reliabilism explains why that JTB isn't knowledge.

Can we know anything (scepticism)? → JTB breaks (Gettier) → what do we perceive? → how is belief justified (this micro)?