Are you thinking of being a sculptor? Then check out the Rebecca Warren survey at the Serpentine Gallery in London. It borders on the sublime but keeps a foot firmly planted in an interior building site. Many parts are stretched across five rooms but we see no whole. Poise, balance and delicateness and electricity enliven relative material poverty and culminate, sometimes, in a triumphant neon halo. But we aren’t in Paradise even though there is a power to be in awe of here. Who’s in charge the artist or the material?