In the _Institutes_ of the learned but uncritical Coke there are many tales drawn from a curious Anglo-French treatise entitled the _Mirror of Justices_, "a very ancient and learned treatise of the laws and usages of this kingdom," opined Sir Edward, "whereby the Common-wealth of our nation was governed about eleven hundred years past." For a long time the book was accepted at Coke's high valuation with no little injury to the sober study of legal antiquities. Then it was exposed as apocryphal by Sir Francis Palgrave. It could not be taken as evidence "concerning the early jurisprudence of Anglo-Saxon England." But could it be taken as evidence of anything at all? _Wahrheit und Dichtung_ was Vinogradoff's verdict,--sediments of truth floating in a sea of absurdity. It was worth while at least to establish the text and to examine the credentials of a treatise which, like the pseudo-Ingulph, had done much harm to sound learning. One reassuring result was obtained from Mr Whittaker's critical enquiry into the manuscript. The _Mirror_ was never in the middle ages a popular or influential book. It existed in a single unique manuscript. Such authority as it obtained was conferred upon it by lawyers who lived some three hundred years after it was written, were "greedy of old tales and not too critical of the source from which they were derived." Still, in a book so full of concrete positive statement, so full of denunciation of practical abuses, there might for all its rubble of absurdity be a quarry for historians.