Chris Corrigan has been doing some interesting bloging recently about circles and quotes this from Danish polymath Piet Hein:

Man is the animal that draws lines which he himself then stumbles over. In the whole pattern of civilization there have been two tendencies, one toward straight lines and rectangular patterns and one toward circular lines. There are reasons, mechanical and psychological, for both tendencies. Things made with straight lines fit well together and save space. And we can move easily - physically or mentally - around things made with round lines.

Spookily I read the following this morning from Alan Watts:

Civilized human beings, and Westerners in particular, are always trying to straighten things out and put them in rectilinear boxes. This arises out of the Greek superstition that there are three dimensions of space and from Euclid's brutally oversimplified fantasies of a world consisting of points, lines, surfaces, circles and cubes. It is hard to persuade and educated Westerner that Euclid was simply a fantast and that his so-called geometry had nothing to do with measuring the earth, but only with working out the rules of his own rather rigid and simple mind. Earth wiggles, water streams and waves, and nature in general dances and swings, but Euclid's mind never reached the biological level. It stopped in the purely crystalline stage of evolution. This is why generation after generation of school children have been bamboozled into the notion that a straight line is simpler, and thus more intelligible, than a wiggle. Ever after we have been trying to subjugate all experience, knowledge, and action to the supposed clarity and intelligibility of straight lines.

from Alan Watts' essay What On Earth Are We Doing?