Imagine that this is the back of your eye, okay? And these are two projections from the world. 00:03:22 They're identical in every single way. Identical in shape, size, spectral content. They are the same, as far as your eye is concerned. And yet they come from completely different sources. The one on the right comes from a yellow surface, in shadow, oriented facing the left, viewed through a pinkish medium. 00:03:48 The one on the left comes from an orange surface, under direct light, facing to the right, viewed through sort of a bluish medium. Completely different meanings, giving rise to the exact same retinal information. And yet it's only the retinal information that we get. So how on Earth do we even see? So if you remember anything in this next 18 minutes, remember this: 00:04:13 that the light that falls onto your eye, sensory information, is meaningless, because it could mean literally anything. And what's true for sensory information is true for information generally.