Theories of perception (Philosophy HL)

The big idea: Look at a mug on the table. It feels like you're seeing the mug itself — the real thing, right there.

The puzzle of perception: But are you? Or are you only seeing a picture of the mug your mind builds from light hitting your eyes? This is the puzzle of perception: how close do we really get to the world?

There are three main answers, and they line up on a scale — from 'you see reality directly' to 'there is no outside reality to see'. We'll meet each one, then test them with a single sharp argument.

Start with the view that matches how seeing feels — then hit it with the argument that shakes it.

Direct realism: you see the thing itself: Direct realism says the obvious thing: when you see the mug, you see the actual mug — not a copy, not a picture. The world is pretty much as it appears, and you're in direct contact with it. Simple, and it fits everyday life.

The argument from illusion

But here's the crack. Dip a straight stick in water — it looks bent. Yet the stick is straight. So what you're seeing (a bent shape) isn't the same as what's really there (a straight stick).

Why it matters: If what you see can differ from what's there, then you're not seeing the thing itself directly — you're seeing an appearance. That's the argument from illusion, and it's the big threat to direct realism.

Checkpoint — the crack: In one line: appearances can differ from reality, so what you see is an appearance, not the thing itself. That pushes us past direct realism to the next view.

If we see appearances, two views compete over what lies behind them.

Representative realism: images of a real world: Representative realism keeps the outside world but adds a middle step.

Like a screen: Perception is like watching the world on a screen — the broadcast is real, but you only ever see the screen. The worry: if you only ever see the screen, how do you check it matches the world?

Idealism: it's images all the way: The philosopher George Berkeley took the bold step. If all we ever meet are mental images, why believe in a hidden material world behind them at all? Idealism says the mug just is a stable bundle of experiences. 'To be is to be perceived.' No screen and a hidden broadcast — just the images, held together (for Berkeley) by God.

Go further — higher-level insight: See the trade-off each view makes. Naming each view's price is a top-band move.

Checkpoint — the slide: In one line: direct realism (see the world) → representative realism (see images OF a world) → idealism (only images, no world behind). Each fixes the last one's problem but pays a price.