Scorn is often poured on judgments of the type described, and the expert who produces them in a court of law is the delight of the skillful cross-examiner. True, the only merit of snap opinions based on defective sensibility and inadequate experience is that they have a fifty-fifty chance of being right; but with sensibility backed by knowledge, an almost supra-rational instinct develops as to what is genuine or false. The so-called impression or hunch is, in such circumstances, more accurately described as a synthesis of many experiences. It is often forgotten that such almost instinctive judgments are not confined to art and archaeology. They play an important part in the sciences (where they are called hypotheses), in politics, in war, in business, and many other fields. Their value varies with the men who make them; but this does not lessen their potential value, and their occasional indispensability. In the detection of two particular types of forgery they are especially useful. Imitations of contemporary work can be very baffling, since the forger works with materials which were or might have been used in genuine work, does not have to give an appearance of age, and works against the same general background as does the artist he imitates. Similarly, a school piece which is misrepresented as the work of an old master, was produced in a similar physical and emotional environment. In such cases, a final verdict often has to be based on nothing but imponderable elements of style, realizable only through feeling based on knowledge. [Illustration: ABOVE: An imitation of the work of John Constable, distinguished from an original (BELOW) by its coarse handling and mistakes in topography.] [Illustration: (genuine example)]