logical inferences, yet even then it enters into the distinction between a critical, skeptical, and irresponsive body of spectators, and one that is sympathetic, acquiescent, and cordial; it renders it easier to effect bold and striking impressions with a larger audience than with a smaller one; its power is greatest, however, where the subjective factor in deception is greatest, more particularly in such forms of deception as have been last described. In brief, we must add to the many factors which contribute to deception the recognized lowering of critical ability, of the power of accurate observation, indeed of rationality, which merely being one of a crowd induces. The conjurer finds it easier to perform to large audiences because, among other reasons, it is easier to arouse their admiration and sympathy, easier to make them forget themselves and enter into the uncritical spirit of wonderland. It would seem that in some respects the critical tone of an assembly, like the strength of a chain, is that of its weakest member. "The mental quality of the individuals in a crowd," says M. Le Bon, "is without importance. From the moment that they are in the crowd the ignorant and the learned are equally incapable of observation." VI In this review of the types of deception I have made no mention of such devices as the gaining of one's confidence for selfish ends, preying upon ignorance or fear, acting the friend while at heart the enemy, planned connivance and skilful plotting, together with the whole outfit of insincerity, villainy, and crime. It is not that these are without interest or are unrelated to the several types of deception above considered, but that they are too complex and too heterogeneous to be capable of ready or rigid analysis. When deception becomes an art of life, consciously planned and craftily executed, there must be acting and subterfuge and evasion to maintain the appearance of sincerity. The psychology of the processes therein concerned is almost coincident with the range of social, intellectual, and emotional influences. Complex as these operations may be, they have, in common with the less intricate forms of deception, the attempt to parallel the conditions underlying the logical inferences which it is desired to induce. If we add this great class of deceptions to those already enumerated, we may perhaps realize how vast is its domain, and how long and sad must be the chapter that records the history of human error.