"Vision is a form of cognition: the kinds of things we see shape the ways we think."

"That is why it is so hard to imagine the visual experience of our prehistoric ancestors, or, for that matter, the girls of nineteenth-century Malawi, who lived in a world without right angles. Inhabitants of, say, late Neolithic Orkney would only have seen a handful of perpendicular lines a day: tools, shaped stones, perhaps some simple geometric decoration on a pot. For the most part, their world was curved: circular buildings, round tombs, stone circles, rounded clay vessels."

What has rectilinearity done to our minds?