In order to get a better grasp of the situation in connexion with mental disorders, we may profitably consider first how unconscious psychic material behaves in the case of normal people, especially trying to visualize what in normal men is apt to be unconscious. As a preliminary to this knowledge we must get a complete understanding of what is contained in the conscious mind; and then, by a process of elimination we may expect to find what is contained in the unconscious, for obviously--_per exclusionem_--what is in the conscious cannot be unconscious. For this purpose we examine all activities, interests, passions, cares, and joys, which are conscious to the individual. All that we are thus able to discover becomes, _ipso facto_, of no further moment as a content of the unconscious, and we may then expect to find only those things contained in the unconscious which we have not found in the conscious mind. Let us take a concrete example: A merchant, who is happily married, father of two children, thorough and painstaking in his business affairs, and at the same time trying in a reasonable degree to improve his position in the world, carries himself with self-respect, is enlightened in religious matters, and even belongs to a society for the discussion of liberal ideas. What can we reasonably consider to be the content of the unconscious in the case of such an individual? Considered from the above theoretical standpoint, everything in the personality that is not contained in the conscious mind should be found in the unconscious. Let us agree, then, that this man consciously considers himself to possess all the fine attributes we have just described--no more, no less. Then it must obviously result that he is entirely unaware that a man may be not merely industrious, thorough, and painstaking, but that he may also be careless, indifferent, untrustworthy; for some of these last attributes are the common heritage of mankind and may be found to be an essential component of every character. This worthy merchant forgets that quite recently he allowed several letters to remain unanswered which he could easily have answered at once. He forgets, too, that he failed to bring a book home which his wife has asked him to get at the book-stall, where she had previously ordered it, although he might easily have made a note of her wish. But such occurrences are common with him. Therefore we are obliged to conclude that he is also lazy and untrustworthy. He is convinced that he is a thoroughly loyal subject; but for all that he failed to declare the whole of his income to the assessor, and when they raise his taxes, he votes for the Socialists.