 While conceptual art in its purest form might arguably be limited to works produced during these five or six years half a century ago, it seems overly narrow – certainly from a philosophical perspective – to limit our inquiry to works produced during that period alone. For although the work created during that time might generally be conceived as more directly anti-establishment and anti-consumerist than later conceptual art, the spirit of early conceptual art seems to have carried on relatively undiluted into the very late twentieth and twenty-first centuries, as witnessed by pieces such as Tracey Emin’s Unmade Bed, Damian Hirst’s The Physical Impossibility of Death in the Mind of Someone Living, and Ai Weiwei’s Surveillance Camera.