Arrières-pensées (Second Thoughts) by Yves Tanguy, 1939. Oil on canvas. On display in the San Francisco Museum of Modern Art on the second floor.

The Surrealists believed that dreams and reality could be resolved into a kind of absolute reality - or, as they dubbed it, surreality. Here, Tanguy presents what he called a mindscape: an eerie, illusionistic landscape that combines aspects of both realms.

The soft, opalescent palette and mysterious, biomorphic forms (bonelike shapes interconnected by delicately etched lines) give the feeling of being in another world, while the artist’s use of traditional perspective creates the illusion of realistic, three-dimensional space.

(via SF MOMA)

One of the things that always strikes me about Tanguy’s work is the direction and usage of light. The first light is directed from the viewer-side of the painting at a low trajectory however there is another source of light coming from behind the forms. The objects are both harshly front-lit and softly backlit, an impossible phenomenon.