St. Peter, by Aleijandinho

Energetic, emotional. By a major Brazilian Baroque artist.

Reliquary bust (mid 1700s), by Aleijadinho

Assertive yet compassionate. Collapses powerful imagery--face, heart, starburst, cardinal's mitre--into an affecting whole.

Vendor of Vegetables, by Pieter Aertsen (1508-1575), Flanders

Spooky. A cramped, chocked-full composition that overwhelms you as much as the smells of a 16th century marketplace must have. Part of a series of remarkably bizarre marketplace paintings by Aersten.

Skeletal Ghost (1830), by Katsushika Hokusai, Japan

Where would you start if someone asked you to depict the relationship between two worlds--between the dead and the living, the unconscious and conscious, the sleeping and the wakeful, your inside and the outside? Hokusai started with a protagonist from the other side, drawing back a curtain so he can peek from one world into ours. Our world seems a little more flowing--what are those white waves? But the delicate curtain--exactly what diaphanous boundary does it hang across?--is just as full of beauty. And the onlooker, as well as being spooky, seems impish, maybe even raffish about being able to peek in.

This is one of my favorite works of art, about the worlds we carry along with us, and the pleasure of cutting across them.