[saint-loup]

Actually, Universal Principles of Design is a somewhat misleading title. I was excepting a book deeply theory-driven, with few principles derived from even fewer concepts, but it turned out to be a compilation of 210 notions loosely categorized. It contains the topics you suggested, and many more. I think his purpose was pragmatic, but I'm not sure it suceeded.

Indeed, statements like "four rules cover 90% of design", as you said, are both theoretical and practical: they strive to simplify and unify a conceptual landscape, which in turns helps you in your work, because you don't have to remember and apply many vague heuristics.

Of course, whether a true and satisfying theory of design exists, is another matter.

EDIT: Awful spelling.