Whenever I teach an art history survey (as I have for a decade in at least five Boston area institutions), I begin by asking my students for definitions of art. Invariably, someone will note that art can be defined as anything found in a museum gallery. Fair enough.

This explains the joke Marcel Duchamp was making when he submitted a urinal as a work of sculpture by the artist “R. Mutt.” (Incidentally, why is there not a rock band called “R. Mutt”? Oh wait, I just found their MySpace page.) Once it’s in a museum, then it’s art, right?

It may be a cliched New Yorker cartoon to picture museum goers staring at trash cans or fire extinguishers but from working in museums, I can assure you that that sort of intense looking at mundane objects does happen. Something about entering a museum (maybe it’s a high admission fee making you feel you need to get your money’s worth) puts you in a frame of mind where you have heightened aesthetic perceptions, almost like a drug. Have you ever noticed, man, that the negative space on an Exit sign looks like a house turned on its side? Whoa.

The inverse of this phenomenon is true, as well. When we’re not in a gallery, we don’t perceive things the same way. The greatest challenge for public art is that no one is looking at it. People see it, but hardly anyone looks at it because our aesthetic perception is usually turned way down low as we hustle through the streets to our next appointment. Many visitors to the Boston Public Gardens assume that the west facing equestrian statue must represent Paul Revere and hardly stop to look at his face, so familiar from the dollar bill. This isn’t always the case with public art, however, as a recent post on this blog by the artist Wen-ti Tsen testifies; sometimes people look.

But do we look enough? If I expand the definition of public art to include architecture and landscape gardening (hey, if Kant can, I can), then courthouses, parks, tree lined avenues, hotels and skyscrapers are all worth a look. Seen in this way, all of our major cities are comparable to most museum galleries. And it is possible to see it in this way.

One of the best student comments I ever had was from a woman who told me that her commute had changed since learning about art. She got on the bus and she just looked at the buildings going by, noticing details and proportions and all the work that went into them. I don’t mean to suggest that this sort of perception is only available to students of art history, just that there is a different sort of perception available to all of us, and we can tap into it through history, or our spiritual beliefs, or by simply being more aware of our surroundings. We just need to turn on our "art vision" every once in a while.

Imagine taking a bus through a museum every day.