The more we peer into the pre-Copernican universe, the more harmonies we find. It is both our gain and our loss that those now seem ludicrous.
William T. Vollmann, Uncentering the Earth
Vollmann is often annoyingly condescending, but he managed to explain and tie together the theories of four elements, four humours, etc. a lot better in one page than an Oxford lecturer did in an hour.