The Observer view: how Leonardo, Van Gogh and Monet help us to transcend the gloom

Four exhibitions in London this autumn remind us that creativity and imagination are the opposite of authoritarianismThere can rarely have been such a meeting of political jeopardy and artistic genius as in Florence in 1504. After the violent overthrow of the Medici family a decade earlier, and the execution of the zealot Savanorola in 1498, the new Florentine government, beset by ongoing wars with Pisa, was desperate for symbols to help stabilise the city’s fragile republic. To that end,