For a few days in October, bright blue skies bathed the French capital in a light so vivid that the streets resembled a hyper-real painting. Avenue Winston Churchill was empty of traffic but full of collectors, dealers, curators and other art world types, gathered for Paris art week. They milled about in the sun or clustered around food vans, coffee stands and pieces of sculpture.

On either side of the esplanade that runs between the Champs Élysées and the Seine is Charles Girault’s exquisite pair of beaux arts buildings, the Grand Palais and the Petit Palais. The connection their architect had originally intended between the two buildings, in 1900, has been re-established across a space now usually occupied by cars and buses. At the foot of the Grand Palais, which houses the Foire International d’Art Contemporaine (Fiac), white letters were painted on the road surface: “L’art est ce qui aide à tirer de l’inertie” – art will help to pull us out of inertia – a phrase coined in 1971 by artist-poet Henri Michaux, reiterated here by nonagenarian French poster artist Jacques Villeglé.

One year on from the Bataclan shootings the Paris art world is exhibiting a defiant response to that violence, the cultural face of a city determined to find its avant garde soul again. Armed soldiers and police patrol the streets and the Métro; rigorous bag searches produce hour-long queues at every tourist attraction. But, says art consultant Laurence Dreyfus: “When you are in difficulty, you are ready to fight. We are good at reinvention; we are creative.”

Fiac director Jennifer Flay is also bullish. “After Bataclan and Nice, installing pop-up cafes on the street was a gesture, a statement of intent. It would be caving in to huddle and feel sorry for ourselves,” she says. “Fiac’s installation of Ugo Rondinone’s five white aluminium olive trees and five stone men in the Place Vendôme is about standing up straight and strong, debout, but is also a cry for peace.”

O.T., 2015, by Katharina Grosse Photograph: Francois Mori/AP

As part of the temporary closure of Avenue Winston Churchill, Villeglé’s works were one of several public art projects initiated by Fiac, which extended its reach to the Petit Palais for the first time this year and occupied more outdoor space than ever before. Fiac’s 43rd edition delivered a clear message that builds on the Parisian response to the Bataclan shootings.

With ordinary people defiantly continuing to socialise at the city’s bars and bistros, the success of Paris art week revealed something else about the city’s state of mind. With unexpectedly strong sales at Fiac, three successful satellites – the Outsider art fair, Paris Internationale and Asia Now – a slew of world-class museum shows and unprecedented grassroots activity show that Paris is now home to a vibrant art scene that threatens to bump London from its pedestal as Europe’s contemporary art hub.

This year’s Fiac exhibition of sculpture and three architectural installations by Jean Prouvé, Jean Nouvel and Ron Arad, in the Jardin des Tuileries, is an attempt by Flay, with much help from Anne Hidalgo, the mayor of Paris, to move beyond the commercial aspect of Fiac and create a new public for art. “It can’t just be entre-sois. If art is more generously and democratically spread within a society, it can be an equaliser, a socially cohesive force.”

Artist Kader Attia, winner of the 2016 Prix Marcel Duchamp, agrees. “I was depressed after Charlie Hebdo, but Bataclan really kicked my ass. I had to do something.” With his friend and business partner Zico Selloum, Attia raised funds to open a hybrid restaurant and art space, La Colonie, in the multicultural 10th arrondissement. La Colonie mixes art, music, critical thinking, debate and cultural activism, with a focus on the stories of minorities. “For a while I thought French society, like many European societies, was fragmented,” says Attia. “But I think there is a kind of repairing culture happening in Paris now. In a city where having a drink on a terrace can be considered extremely dangerous, French society has finally begun to consider itself part of a global village and not the centre of the world.”

La Colonie’s launch night was packed with people of all ages, the local immigrant community mingling with the Fiac crowd. An artists’ talk was followed by couscous cooked by Attia’s mother, a free bar and dancing.

Attia is based in Berlin, but grew up in Algeria and the Paris suburbs. “France has never really understood the Arab world or the Middle East,” he says. “But there is a new wave in Paris now.”

Fatal Attraction, by Gloria Friedmann Photograph: Francois Guillot/AFP/Getty Images

Alexandra Fain, director of Asia Now, Europe’s only dedicated Asian art fair, says she finds a new openness in Paris. “Curators don’t pretend they know everything any longer. They are now able to say ‘we don’t know’ and find people who do. Paris understands it is in its best interests to open its eyes to the rest of the world, not just to America or Europe, but to the South American, the African and the Asian scene.”

The energy in Paris is palpable and growing, says Austrian gallerist Thaddaeus Ropac, who gave a party at his hangar-like space at Pantin, on the north-east edge of Paris, during Fiac. “It was so crowded I was afraid for the paintings,” he says. “I couldn’t believe that 750 people came all the way out to Pantin so late at night.”

Over coffee at his other gallery space in central Paris, which opened in 1990, Ropac explains that Paris doesn’t need a lucrative market to support it; it has learned to survive. “The art market crash in 1991 took Paris further down than other cities. London reinvented itself with the YBAs [Young British Artists], New York bounced back, Berlin began to attract artists like a magnet, but Paris suffered. It has taken driving forces of contemporary art like the Palais de Tokyo and now the Monnaie de Paris to bring Paris back to life.”

What Ropac loves about Paris, he says, is its “amazing, loyal audience” for art. “They’re intellectual. And it is considered vulgar to mention money. You go to a dinner in London and people blast into your face how much their house cost, how much they earn.”

As we talk, India’s most famous artist couple, Bharti Kher and Subodh Gupta, walk into the gallery. “Only the Americans did not come this year,” says Ropac. “Our biggest clients told us they were afraid. But this Fiac has been incredible, we did better than last year, without Americans, which is remarkable.”