On the subjects of "pretty", "intuitive", and other elusive and indefinable notions

I often hear or read about pretty or ugly maps; intuitive or unintuitive user interfaces. What jumps out at me from these discussions is that people don't always agree on what pretty or intuitive is. No surprise there.

Can "pretty" and "intuitive" be defined? Can they be understood? Or is trying to understand beauty through analysis exactly the wrong approach? There are formulae for beauty, the golden ratio being one example. But is there – or can there be – a universal understanding (and therefore definition) of what "pretty" is? The answer is, of course, no. If there were, then we would all be great artists, designers, architects. All one would have to do is apply the universally-accepted formula for beauty.

This is an age-old subject, studied at great length by humanity's greatest minds. Or more recently, beautifully summarized by Robert M. Pirsig in "Zen and the Art of Motorcycle Maintenance: An Inquiry into Values".

Pirsig divides human understanding into two kinds - classical and romantic. He illustrates his concept thus:

"The classical mode proceeds by reason and by laws. The classic style is straightforward, unadorned, unemotional, economical and carefully proportioned. Its purpose is to bring order out of chaos. The romantic mode is primarily inspirational, imaginative, creative, and intuitive. Feelings rather than facts predominate. Motorcycle riding is romantic while motorcycle maintenance is purely classic."

So can (or should) a map be "pretty"? Can a UI be "intuitive"? And can the same person or group of people who made the map/program "work" also make them pretty/intuitive? As a student and follower of Pirsig's, I submit that it takes a person unconstrained by modern-day western specialization to achieve the synthesis of classic and romantic (or, rather, to avoid separating them in the first place). Such as Leonardo da Vinci. Or Steve Jobs. That person can be of any gender.