I just finished reading Visual Function, by Paul Mijksenaar. It's a fairly seminal book in graphic design. I'm interested in graphic design not so much because I do it (which I don't really), but because I think we're all designers these days.

Mijksenaar at one point talks about the Roman architect Vitruvius who said that architecture should follow these criteria:

I think everything we do or build should be informed by these criteria. Don't you?