Would Sartre recognise his old haunts today?

He would have found it laughable that the upstairs room at the Café de Flore is now a non-smoking area

Jean Paul Sartre was born 100 years ago, so Paris is currently full of people making centenary programmes about the great man, and I am no exception. Yes, there I was in Paris last week, helping to make a Radio 4 programme about Sartre, when an enormous impulse came over me and my producer, Merilyn, to stop at a pavement café for a coffee.

Jean Paul Sartre was born 100 years ago, so Paris is currently full of people making centenary programmes about the great man, and I am no exception. Yes, there I was in Paris last week, helping to make a Radio 4 programme about Sartre, when an enormous impulse came over me and my producer, Merilyn, to stop at a pavement café for a coffee.

This happened quite often during our labours. Sometimes you can disguise it as research. Sartre and Simone de Beauvoir spent a lot of time in the upstairs room at the Café de Flore, near the Café des Deux Magots, writing at separate tables and smoking away generously, so Merilyn and I thought that the least we could do was to have breakfast in the very same room where Sartre and Simone laboured away.

It is a first-floor room, L-shaped, looking out over the Boulevard Saint Germain. At least it would look out over the Boulevard Saint Germain if the view was not blocked by a shrubbery planted outside the window, on top of the front entrance.

I don't think Sartre would have liked that. He wasn't much of a man for the natural world, and countryside, and greenery. He was a city man through and through. The only plant he really approved of was Nicotiana tabacum, of which he inhaled vast quantities. You seldom see a photograph of Sartre not smoking. Perhaps the only photo in which you can guarantee not to see a cigarette is the one advertising the Sartre exhibition at the Bibliothèque Nationale. There was a fag in his fingers originally, but it has been airbrushed out.

He would have found that laughable. He would also have found it laughable that the upstairs room at the Café de Flore is now a non-smoking area, though he might have been mollified to learn that in 1994, 15 years after his death, the Café de Flore instituted an annual prize for the best new book by a young author. (The prize is €6,000 and a free glass of Pouilly Fumé every day during the year. Very French.)

Sartre was everywhere in the air. Merilyn told me she had even popped into Notre Dame and found a big picture of Jean Paul there, with lots of people lighting candles to him.

"To Sartre?!" I said.

"No, you fool - to John Paul II," she said.

So, as I was saying, after days of interviews with Sartristes, or Sartriens, or even - as Michel Contal described himself - a Sartrologist, Merilyn and I felt we had earned another coffee, and sank into a pavement café table near the HQ of publishers Gallimard. As our coffees arrived, I saw a distinguished-looking couple enter the café. They looked very English. My eye caught his eye. He flickered, as if he recognised me. I thought I recognised him.

"That man who has just gone in with his wife," I said, "is the spitting image of Dr Thomas Stuttaford."

"Who is Dr Thomas Stuttaford?"

"Resident doctor on The Times. I have met him at The Oldie, where he also writes sometimes."

"Are you going to say hello?"

"I don't know."

After all, it takes a certain courage to accost a man who looks vaguely like an acquaintance, but who might equally be a Paraguayan diplomat or an Italian surgeon. But emboldened by all the caffeine swilling around in my system, I chanced my arm.

"Excuse me, but are you by any chance Dr Thomas Stuttaford ?"

"No," he said, in a rich Welsh accent. "Who is Dr Thomas Stuttaford ?"

It was going to be a long afternoon, if I was going to have to explain to everyone I met who Dr Thomas Stuttaford was. I explained. Luckily, he took pity on me, and gave me his card.

"I am Professor Geraint John. I am an architect, of football stadiums."

"Stadiums ...?"

"You may have heard of Wembley ... Cardiff Millennium Stadium ..."

We had a nice chat, and as he left, he said to me, with a twinkle: "Remember, if you keep to a moderate lifestyle, you should live for many years yet."

I think Sartre would have liked that. Here was a man who designed top-class football stadiums and yet had chosen of his own free will to be, just for a moment, something very different: a tip-top media doctor. Very existential.