CAROLINE WALKER BYNUM RAISES an interesting question in her 2005 book, Metamorphosis and Identity: “Were medieval werewolves really metempsychosis?” Metempsychosis is the transmigration of the soul from one animal to another, and odd as the question seems in thinking about the South African artist William Kentridge, it has a curious resonance with this survey, recently on view in San Francisco, precisely because there is a single essence that inhabits his every theme and leap from medium to medium—whether drawing, animation, installation, sculpture, or opera—and that is the ruthlessness, or

The press release for Kathryn Spence’s recent exhibition outs her as “an avid birder, gardener, and conservationist,” yet the sculptures—fastidiously arranged bundles of refuse, some of which resemble taxidermied animals—suggest another identity, that of flaneur. While looking at the show, it’s easy to imagine the artist keenly observing the city as she wanders streets, harvesting the bits of refuse used in her work. The listed materials—magazine clippings, plastic bags, string, wire, newspaper—are just the sorts of things abundantly available in gutters and alleys.

Titled “Cloudless White,” the