Stuart and I were sitting on the roof, outside the dormer window, and sipping a little Drambuie. Cigars were for later.

“A beautiful evening, isn’t it?” he said.

“Yeah, the sunset is so orange.”

“You call it orange, but really, how many different colors are there in that sky — even a band of green in it.”

“Where?”

“There, see, above that reddish cloud. Perhaps it’s only a trick of simultaneous contrast, but that green has always fascinated me.”

“I see it now, rather a pale green, almost opal, but green.”

“How much better to see the whole thing, instead of just the calendar version. You know, I always wonder why pretty magazine pictures look so cliched, while the sky in front of us doesn’t. I guess there is a difference between pretty and beautiful.”

“Or, maybe beauty is in the eye of the beholder.”

“Yeah, well, I used to think that.”

I could see Stuart had something on his mind. He usually did.

“Used to?” I asked. “OK, so what is beauty? Personally, I tend to think of Scarlett Johansson.”

“Really? I kind of favor Hedy Lamarr, but then, I’m always a little behind the times. But really, first we have to agree on what kind of beauty we’re talking about. Erotic attractiveness is a completely different thing from esthetic beauty. You could even say they are opposites.”

“How’s that?”

“Because erotic beauty draws us to possess it, while esthetic beauty doesn’t — it fascinates us, but leaves us disinterested, involved but motionless.

“This is the essential difference between art and pornography. If you look at a picture and say, ‘I want that,’ or ‘I wish I were there, seeing that sunset,’ you’re reacting as if to pornography, whether it’s a picture of a naked human or a brazen sunset. Erotic beauty impels you forward into time and history, while esthetic beauty draws you upward and out of the mad stream of time.”

“So you’re saying beauty comes in two categories?”

“Oh, there are lots of other divisions to make. For instance, there’s that ‘eye of the beholder’ question.

“Well, that’s what they say.”

“But it’s an easy way out. It doesn’t really answer anything. Actually, it seems to me that beauty is either internal or external. That is, either it is in the eye of the beholder, or it exists objectively, outside the accident of perception.”

“What do you mean, ‘objective’ beauty? How can that be?”

“Look at it historically. Centuries ago, it was mostly thought that beauty was an objective quality. You had it or you didn’t. Those who say beauty is external to human perception fall into two camps: the transcendent and the inherent. The second camp says that something is beautiful because elements of the physical world are by nature so. The first camp looks beyond the physical world to something metaphysical.

“You mean God?”

“Right. It could be a god or the gods. On the other hand, it could be an unnameable, ineffable mystery at the center of the universe. If a god has made something beautiful, it is then our recognition of that divine intention that is external to our psychologies. It really is beautiful, whether we recognize or not.”

“But what if you don’t believe in any of that supernatural stuff? Where does beauty come from then?”

“Again, two ways. It might simply exist as mathematics does, in its proportions and harmonies; some things may be beautiful the way a triangle has three sides. Such qualities are inherent in the objects we recognize as beautiful. Or, as another possibility, it might be biological, or based on evolution: Certain things may have emerged as ‘beautiful’ in the development of the universe because their beauty promotes evolutionary goals. Thus, a bright, beautiful flower attracts bees — which ensure the survival of the flower species through pollination.

“That’s all fine. But what if beauty really is internal — only the eye of the beholder?”

“Then again we face two choices: If beauty is only found inside us, it is either cultural or acultural.”

“Wait. I thought it was all cultural.”

“You hear that a lot on university campuses nowadays. It’s a popular point of view currently. But it is not the only way of understanding it. A good portion of the academic community has jumped on the bandwagon of cultural identity. Art, for instance, is seen as a way of establishing ethnic pride. It certainly may do this, but it is not the only thing art can or should do. Deconstructionists, for instance, like to look under the rock and find the bugs — what we really mean when we write or talk — and they show us that race, ethnicity, class or power is often at the bottom of things. Powerful White European men, for instance, have tended historically to value powerful White European male art.

“These people have a point, but it isn’t the totality. Beauty isn’t just that powerful White European men, for instance, have tended historically to value powerful White European male art.

“Right. The famous dead White men.”

“The trend is to say that beauty is culturally determined. But I would argue that culture doesn’t define what is beautiful, but what is not beautiful.”

“What is not beautiful?”

“Yeah. For example, the ‘dominant culture’ told a lot of White Americans for a very long time that ‘nappy hair’ wasn’t beautiful. The culture excluded what it wanted to exclude. What was left was deemed beautiful. Various ethnic groups are now turning that same exclusion around on those who formerly excluded them.”

“Oh, White men walk like this, but Black men walk like this, that sort of thing. But you’re saying there’s another way to look at it?”

“Yes, there may be factors at work that range across cultures. Scientists have discovered that there are some things that seem to be universally recognized as beautiful — certain color combinations, or even aspect ratios. In physical beauty — if we want to get back to Scarlett and Hedy — for example, a certain mathematical proportion between hip and waist size seems to transcend culture. Some cultures may value thin women while others like the Rubenesque, but the hip-waist ratio remains constant. Some underlying principles seem to be at work.

“Their work is still new, and their results are fragmentary, but it may be that evolution has hardwired certain esthetic receptors into the human mind.”

“Like a bee before a flower?”

“Right: Does the flower become beautiful to attract the bee? Or does the bee develop a love of beauty to discover the flower? It blurs the distinction between the perceived and the perceiver.”

“Still, I’m not getting it. What sorts of things do we see as beautiful?”

Sometimes, I forget that Stuart is really highly educated. He’s lived his life as some kind of bohemian, shifting cities, or jobs, or lady friends, never settling, and never — this is always discouraging — never writing anything down. But every once in a while, he dredges out some bit of arcana that I might once have studied, but never kept up with.

“Thomas Aquinas,” he started, “the famous 13th Century Christian scholar, said the beautiful has ‘integritas, consonantia and claritas.’ James Joyce’s translation of that from the Latin gives us ‘wholeness, harmony and radiance.’ ”

“Hey — I remember reading Joyce’s comments about a butcher’s basket: To see it apart from its surroundings, as a separate thing, is to see its integritas, its wholeness. As something distinct and not a part of something else.”

“Exactly.”

“Then you look at its parts — the handle, the weave of the reeds, the roundness of the bottom — and you see how those parts interact in the design.

“That is the harmony, or consonantia. But, you know, I’ve never quite accepted his definition of claritas.”

“It’s the tricky one. Joyce claims that once you’ve seen the whole and the parts, both together may join to excite your esthetic appreciation. They become larger, brighter, more meaningful than their simple existence as a basket. They have radiance. But the Latin of Aquinas is less clear.”

“I remember looking it up. My Latin dictionary translates claritas as ‘clearness or brightness’ — words less charged than Joyce’s ‘radiance.’ It also implies a clearness of mind, a plainness and directness of argument.”

“Yes. Meanwhile, there are other qualities we expect from beauty. It should surprise us, but once past the surprise it should feel inevitable.”

“Say, maybe that’s like a good murder mystery: The end should be a surprise, but it shouldn’t be arbitrary. We want to be satisfied, after our astonishment, that this solution to the mystery is the only possible one.”

“As when a Haydn symphony veers off into a strange key, or when the Beatles back a song with a string quartet. You are taken aback at first. Then you realize the perfection of it.”

“But wait,” said. “We still haven’t said what exactly is beauty. Is it a noun? Is it an adjective? — a quality that other nouns possess?”

“Or is it a verb?” Stuart was getting to the crux of the matter, as he saw it. “I’ve worried about the question for years, and I finally decided that if you want to know what beauty is, you must look at it as an event, not a thing. It is an occurrence, a transaction.”

“Hmmm. Sounds like you’re combining the external definition of beauty with the ‘eye of the beholder’ thing?”

“Right. You have the two blades of a scissors. The scissors itself is neither the one blade nor the other, but the two working together: Beauty is your active participation in the perception of the things of the world.”

“So it’s like this: The world is capable of being seen as beautiful — that’s the objective part — and we’re capable of perceiving that beauty — that’s the subjective.

“And where the two things come together, that is beauty.”

“That would make beauty an active thing,” Stuart said, “not a passive observation. You have to pay attention.

“To become part of the event, you must be awake, aware, alive. You must see or hear or feel more intensely than you do in the ordinary world of driving your car or cooking your burger.”

“So that’s why a photo of the sunset is a cliché.”

“The photo becomes a commonly accepted image of beauty, a shorthand for doing the actual work. It becomes a ‘word’ or symbol for the beauty, rather than the event of the beauty itself.”

“That reminds me of what James Agee was writing about in And Let Us Now Praise Famous Men: ‘For in the immediate world, everything is to be discerned, for him who can discern it, and centrally and simply, without either dissection into science, or digestion into art, but with the whole of consciousness, seeking to perceive it as it stands: so that the aspect of a street in sunlight can roar in the heart of itself as a symphony, perhaps as no symphony can: and all of consciousness is shifted from the imagined, the revisive, to the effort to perceive simply the cruel radiance of what is.’ ”

“Or as Blake has it, ‘If the doors of perception were cleansed, everything would appear to man as it is …”

“Infinite.”

“Yes. In a way, beauty is the act of paying attention, deeply and committedly.

“When the commitment isn’t there, the beauty isn’t.”

“So, you’re saying the world is full of things that we habitually think of as beautiful — certain categories of nature or certain subject matter in art — but that our acceptance of them short circuits our actual involvement?”

“The ‘warm bath’ school of beauty. They keep us from participating in the beauty.”

“Someone at the newspaper once wrote about it as ‘paying attention as if you were defusing a bomb.’ ”

“Bingo. Beauty is not for the faint of heart. When you pay attention, the music of Arnold Schoenberg becomes ineffably beautiful. It’s the point of John Cage’s 4’33″ where the ambient sounds you hear while the pianist is not playing are presented to you as beautiful. And they are, if you engage with it properly. Paying attention. What is beauty? Beauty is paying attention. It’s the simplest definition there is.

“And this finally gives us the key to the claritas of Aquinas and Joyce. When seen, truly seen — or by analogy, felt, or ‘apprehended’ in that Joycean locution — your object takes on a mythic significance, as if it glows from within. It is indeed ‘bright.’ It is the crockery of Chardin and the cypresses of Van Gogh. A clarity that glows from within.”

“As you’ve said many times, ‘Every bush is the burning bush.'”

“Wholeness, harmony and radiance,” Stuart said, paraphrasing St. Paul, “and the greatest of these is radiance.”

“Claritas charitas est,” I said, making a lame play on words, in Latin, no less.

“Put that on your T-shirt and see who salutes.”