“All art is erotic.” Or so the fin-de-siecle Viennese architect Adolf Loos once claimed. At the National Gallery in London this autumn, there will be an exhibition devoted to a culture and an era which believed that proposition to be true (with the possible addition of a little death, decadence and neurosis), Bloomberg said.

On display in “Facing the Modern: The Portrait in Vienna 1900” (Oct. 9 through Jan. 12, 2014, sponsored by Credit Suisse) will be pictures by contemporaries of Loos such as Gustav Klimt, Oskar Kokoschka and -- making an unexpected appearance as a visual artist -- the composer Arnold Schoenberg.

While this survey of paintings from the city of Sigmund Freud may well be the big attraction of the London art season, there are many other shows devoted to work from civilizations around the world.

The British Museum will be following Pompeii with “Beyond El Dorado: Power and Gold in Ancient Colombia” (Oct. 17 to March 23, 2014).

The exhibition will contain some 300 highly wrought objects in precious metal of the kind that dangerously over-excited the conquistadors. These would also have fascinated Klimt, who was fond of decoration so long as its symbolism was sexual; and would have horrified Loos, who declared that ornament is crime.

Simultaneously, the British Museum will show some eroticism that is certainly not disguised as symbolic embellishment in “Shunga: Sex and Pleasure in Japanese Art” (Oct. 3 to Jan. 5, 2014).