LIFE Behind the Picture: Children at a Puppet Show, Paris, 1963

Forget the fabled rudeness of the Parisians. Forget the crowds of tourists who flock to the City of Light in the summer, making the city’s winding streets, echoing stone churches and public gardens all but unbearable. Forget that everything, everything, is more expensive in Paris than it has any right to be. Forget that entire neighborhoods sometimes smell, suddenly and inexplicably, of rotting garbage — and then, as suddenly and as inexplicably, the stench vanishes. Forget that everybody smokes, everywhere, at all times, no matter what. Forget all of the worst aspects of the French capital and its denizens, and instead dwell for a moment on the Paris of everyone’s dreams.

Picture the book stalls, the fishermen and the artists with their easels along the Seine. Picture lovers walking the winding streets, drunk on one other, oblivious to everyone and everything but each other. Picture Sacré Cœur and Montmartre, the flower peddlers and the Champs-Elysees, the mansard roofs and the zinc bars, Sainte-Chapelle and the Marais. Picture the Paris, in other words, that inspired Hemingway to remark (according to his friend, the writer and raconteur A.E. Hotchner), “If you are lucky enough to have lived in Paris as a young man, then wherever you go for the rest of your life, it stays with you, for Paris is a moveable feast.”

Of all the pictures made of that Paris — the Paris of the last century, when the city was still largely depicted in beautiful black and white — perhaps none is more famous than Alfred Eisenstaedt’s unforgettable shot of kids at a Parisian puppet show, “Saint George and the Dragon,” at an outdoor theater in 1963. Capturing the thrill, the shock, the shared triumph-over-evil that the children feel at the very moment when St. George slays the mythical beast, Eisenstaedt’s picture feels as fresh as when it was made, more than 50 years ago. Here, the picture tells us, is an innocence that can remind even the most jaded of what it was once like to believe, to really believe, in the stories that unfold before our eyes onstage, or onscreen.

The master photographer himself, meanwhile, said of this very picture: “It took a long time to get the angle I liked. But the best picture is the one I took at the climax of the action. It carries all the excitement of the children screaming, ‘The dragon is slain!’ Very often this sort of thing is only a momentary vision. My brain does not register, only my eyes and finger react. Click.”

Here, as a new season finally begins to take hold after a brutally long, dismal winter, LIFE.com celebrates Paris in the spring through the lens of Eisenstaedt’s puppet-show picture — as well as a number of photographs of Parisians and their city that he made around the same time, but that never ran in LIFE magazine.