The Double Market explores the forensic and moral complexities of art theft, with attention focused throughout on the State's investment in the pursuit and prosecution of the criminals involved. Middlemas believes that ""the art thief is merely a special product of modern industrial society and he will not vanish until the concept of art as investment vanishes."" Middlemas' book is a heavily researched document covering the beginnings of 'modern' art theft from the grand lootings that furnished the Louvre to detailed accounts of recent heists from private and public collections. The motives, ranging from greed to nationalist fervor to aesthetic imperative, and the generally slipshod, though occasionally heroic work of cops and bureaucrats, make the pursuit exciting. The author sees art theft as ""moral blackmail"" against the state since it is not generally a violent crime, not does it intrude upon ""property"" in an ordinary way--works of art belong traditionally to the public domain. Middlemas' sociological speculations are less to the point, fmally, than his important exposes of the vagaries of international law in recovering stolen works.