Hi. Hi, I'm Peter Adamson and you're listening to the History of Philosophy podcast, brought to you with the support of the Philosophy Department at Kings College London and the LMU in Munich online at history of philosophy

dot net. Today's episode the eye sees not itself but by reflection theories of

vision you can tell a lot about theories of vision.

You can tell a lot about a historical period from the examples given by its philosophers.

The medievals love to devise thought experiments invoking their omnipotent God.

When Kant and other German philosophers deal with aesthetic experience,

they speak of the awesomeness of nature, a good fit for the literary culture of the day.

What it says about our own time that philosophers can for the literary culture of the day.

What it says about our own time

that philosophers cannot stop talking

about killing people with runaway trolleys,

I'll leave you to judge.

Back in antiquity, philosophical illustrations

were a bit more wholesome.

The standard example of a visual illusion used already by Plato in his republic is that something

straight, a wooden rod say, will look bent if it is half submerged in water.

For centuries thereafter, philosophers mentioned the apparently bent stick,

but without being able to explain why it looks bent.

The answer, of course, is that although the stick is not

bent the light coming from the stick to your eye is bent or refracted by the water.

When is tempted to say that the water refracts the light whereas air doesn't, but that's not quite right.

Air refracts light too, just not as much as the water does.

...