Art: Solid Man

From the beginning of art history, the word sculpture has meant monoliths —continuous closed forms hewn from one block of marble or cast in one piece of bronze. Then the tin and cardboard constructions that Picasso made in 1912-14 provoked what has become a new orthodoxy: sculpture should be made of open and discontinuous forms, declaring themselves to be not one mass but a sum of parts.

The history of advanced sculpture, from Cubism to the welded-steel structures of David Smith and Anthony Caro, became, in effect, the history of construction. Of late, this has stiffened into dogma; almost any work can...