One warm afternoon this past week, I was strolling through some back streets in a neighborhood near Moda. Here there are cool, atmospheric cafes and shops selling antiques, crafts and other bric-a-brac.

Inside one of the shops, where I was browsing the sparse collection of second-hand English books, hung a poster of Humphrey Bogart and Lauren Bacall. In the photo, they are locked in an embrace: Bogie wears a mariner’s hat, and he’s tipping Bacall slightly back; her eyes are closed, her lips wait to be kissed.

I’ve always been a fan of that particular shot, suffused as it is with all that old Hollywood, smoke-lit glamour. I couldn’t help but feel sentimental, reflecting that the great Bacall passed away this week at the age of 89. She outlived her Bogie by more than half a century.

With this feeling, and thinking it would look good adorning the bare walls of my flat, I enquired about the poster.

“Maalesef,” said the old proprietor, shaking his head and smiling a wan apology. That particular item was not for sale. He offered other posters, including one of Sly Stallone, in a menacing Rambo pose, and another one of De Niro as the lonely, mad Travis Bickle in “Taxi Driver.”

No thanks, I said.

I complimented the old proprietor on his shop, and nodded once more to the Bogart-Bacall poster on my way out the door.

“Evet,” he said, glancing in appreciation at the poster. “Çok guzel. Çok şik.”

As I left the shop and walked further on, passing other shops, I reflected on the passing of Lauren Bacall, and of her life with Bogart, and how even here, on a lonely back street in Istanbul, their stars still shimmer with a pale, luminescent magic. They had a style that seems, even today, to transcend culture and time.

So what is style, I thought? It was an old question.

Years ago, while teaching in Prague, a young Czech woman asked me this same question. More precisely, she asked, what constitutes “style?” She was studying fashion at a nearby university, so I suppose for her the question had a particular significance.

At the time – this was over drinks at a pub near the Charles Bridge – one of the most romantic places in the world, I didn’t have an answer.

After confessing my ignorance, we changed the subject, ordered another drink, and later passed a pleasant evening strolling near the bridge, looking at the swans gliding along the Vltava.

Still, the question intrigued me, so I found myself from time to time collecting observations (I understand that many responsible people – and even many irresponsible ones – would ask, why waste time thinking about such a tenuous and ephemeral subject? I know, but bear with me).

Truman Capote offered one answer. He said that style, if you have it, is something that is as natural as the color of your eyes.  He meant that it is not something that can be cultivated or learned. It cannot be practiced or purchased, even at Tiffany’s. At the time, I suspect Capote was defending his own lifestyle as much as Holly Golightly’s. Fair enough: Like his heroine, the flamboyant Capote was born the way he was, and could never be otherwise.

Decades later,the poet Charles Bukowski offered his own ruminations, in a poem called “Style:” I have met some dogs that have more style than humans/All cats have style, he wrote. Score two for Bukowski: even a cat fresh out of the gutter is still cleaner than most, and at least dogs have a keen sense of loyalty and survival.

But these observations don’t answer the question, they only point to more.

For instance, are we talking about personal style? Are we talking about an approach to one’s work? A philosophy? Or do we mean something else altogether? And isn’t style hopelessly subjective?

Madonna, in her signature song, “Vogue,” scarcely bothered with such questions or explanations. Instead, she just listed off names of people who she felt had it. Greta Garbo, and Monroe, Deitrich and DiMaggio … You know the rest.

With Bacall’s passing this week went the last surviving member of the 16 people on Madonna’s famous list.  Of course, there is Madonna herself – who, it could be argued, has at times over the course of her long career shown flashes of the kind of savoir-faire, elan and soigne insouciance (why do we so often have to resort to French when we talk about style) qualities she celebrates in the song, if albeit a bit forced.

So what is ‘style?’ The question remains unanswered. Like art, style possesses the beauty and satisfaction of having no real definition. Some have it, most don’t. In its place, most celebrities have merely a certain flickering, photogenic scintillation that quickly passes with familiarity. Or they have  personality or charm, or the ability to grab our attention.

I would offer that style is a something akin to instinct; it stems from one’s view of oneself, partnered with the search for our place in the outside world. Style is a reflection of the soul. Like all reflections, there is some degree of distortion. The shadow points to the form, defines it, but does not capture it.

In Lauren Bacall, there was the voice, that famous purr, which in reality was not her true speaking voice. At the age of 19, playing opposite Bogart, she was coached to alter, and lower, her natural voice to attain the smoky register that was deemed appropriate for a 1940s screen femme fatale. In the end, she ended up, by accident or design, keeping that voice.

“When Bogart fell in love with Bacall, he fell in love with the role she played,” a romantic-cynic once observed, “and so she ended up playing that role for the rest of her life.”

Of course, like all forms of magic, there is always a bit of sleight of hand, a trick. As Tennessee Williams, another stylist, observed: “After all, fifty percent of a woman’s charm is illusion.”

I suppose the final test then, is whether that illusion endures the test of time. In Bacall’s case, I think it has. Maybe that’s why the old shopkeeper in Kadikoy wouldn’t sell me the picture. I can understand. Far too often style has been belittled in favor of what is called “substance.” But as I said, the two are linked, and style – true style, whatever it is – adds a mist of glamour to even the dingiest of life’s corridors. 

James Tressler,whose books include “Lost Coast D.A.” and “Letters from Istanbul, Vol. 1,” is a former Times-Standard reporter. He lives in Istanbul.