The female nude in Western painting rested for centuries on an accepted convention: the figure was permissible so long as she was a goddess, an allegory, or a distant myth. Titian's Venus of Urbino (1538) was the classic instance of that convention. In 1863 Édouard Manet took that very painting as his template — and turned every detail into the present.

Olympia is no goddess; she was a courtesan the Parisian viewer of the day recognised at once. The velvet ribbon at her neck, the slipper on her foot, the orchid in her hair, the bouquet her maid brings in — all contemporary and concrete. The most shocking element was the gaze: in place of Venus's shy, averted air, Olympia looks directly, defiantly, at the viewer. That gaze, sizing up the client or the painter, lifts the viewer out of the voyeur's position and makes him the one addressed.

Manet's method was equally subversive. Instead of soft transitions and academic modelling he used flat, hard light; the body is almost shadowless, flat as if cut and pasted. Critics found the technique "crude" and the figure "ugly"; when the painting hung at the 1865 Salon the crowd was furious and guards had to be posted. But young painters saw something else: that a painting could no longer be an illusion seen through a window but a surface confessing its own reality of paint.

Manet founded no movement and wrote no manifesto; yet everyone from the Impressionists to the Cubists took him as the starting point. Olympia is the threshold that carried painting's subject from the "idealised past" to the "present being looked at". It hangs today in the Musée d'Orsay; the viewer standing before it is still the one that gaze addresses.