Why are we so in love with the art of the 1960s and ’70s? Maybe because in our times of nostalgia and ironic detachment, it promises to satisfy a very contemporary desire for authenticity. Artists from that period, we feel, were exploring, not revisiting; their formal experiments were original, driven by an urgency that was fed by a belief in aesthetic, social, and political transformation. Maybe something of this utopian drive lives on in certain recent manifestations of what might be called social sculpture, but in the more object-based forms of contemporary art, this spirit seems to be lost.