the image on the background of this page is a fractal.

fractals are aesthetic images created by complex mathematical formulas, discovered by several authors and whose forms replicate nature's own.

(ok, maybe you don't find them so aesthetic, but they do fulfill their function.)

when it comes to Design, it's roughly the same: aesthetics are based on a couple of highly complex theories, to which several authors contributed. our brain perceives such aesthetics in a similar way as to how it reads nature.