When I saw Art Basel C.E.O. Noah Horowitz on the floor of Art Basel Paris on Wednesday, standing in the vaulted, sun-drenched Grand Palais a few hours after the fair opened, he looked relieved—and more than a little pleased with himself. He was grinning, and slapping backs, because the fair and its surrounding culture events were already drawing near-universal acclaim. French President Emmanuel Macron would visit the fair two days later, along with a phalanx of dignitaries, and it was not hard to infer from Horowitz’s demeanor that the various political, business, and cultural stakeholders who had brought the Olympics to Paris in August were equally interested in seeing the City of Lights demonstrate its bona fides as a leader in the world of art and culture.