As regards intentional imposture, it may be said in general that all men are subject to be duped in matters of which they have no working knowledge and which appeal strongly to the emotions. The application of this principle to quack medicine, to commercial swindles, and to the ever-reappearing impostures relating to supposed communication with spirits, is too plain to be enlarged upon. While it is an advantage, even to a charlatan, to believe in himself, the susceptibility of a large part of us to be duped by quacks of one sort or another is obvious enough, and shows that the work of free institutions in developing shrewdness is by no means complete. Probably a close and candid consideration of the matter would lead to the conclusion that everyone is something of an impostor, that we all pose more or less, under the impulse to produce a desired impression upon others. As social and imaginative beings we must set store by our appearance; and it is hardly possible to do so without in some degree adapting that appearance to the impression we wish to make. It is only when this adaptation takes the form of deliberate and injurious deceit that much fault can be found with it. “We all,” says Stevenson in his essay on Pepys, “whether we write or speak, must somewhat drape ourselves when we address our fellows; at a given moment we apprehend our character and acts by some particular side; we are merry with one, grave with another, as befits the nature and demands of the relation.” If we never tried to seem a little better than we are, how could we improve or “train ourselves from the outside inward”? And the same impulse to show the world a better or idealized aspect of ourselves finds an organized expression in the various professions and classes, each of which has to some extent a cant or pose, which its members assume unconsciously, for the most part, but which has the effect of a conspiracy to work upon the credulity of the rest of the world. There is a cant not only of theology and of philanthropy, but also of law, medicine, teaching, even of science—perhaps especially of science, just now, since the more a particular kind of merit is recognized and admired, the more it is likely to be assumed by the unworthy. As theology goes down and science comes up, the affectation of disinterestedness and of exactness in method tends to supplant the affectation of piety.