The understanding of these two levels of the mind may be rendered clearer if we next consider the uses to which they are put. Supposing a person is sitting in a room listening to a lecture, of what will he be aware? Firstly, his attention will be concentrated upon the lecture, and, secondly, he will be dimly conscious of the sounds made by the traffic in the street outside. By an effort of will he will pay attention to those ideas only which are connected with the lecture, and exclude from consciousness those which are connected with the street traffic; or, to express the process in psychological terms, we may say that all the ideas connected with the lecture are admitted to the focus of consciousness, and all ideas connected with the street noises are kept in the fringe of consciousness, and that the censor-sieve is so adjusted that ideas in the fringe may not intrude upon the focus. Its meshes may be conceived as being of such a size that only the compact little ideas appertaining to the lecture can pass through them, and the undefined ideas connected with the street traffic are held back. It will readily be seen that our powers of concentration depend upon the satisfactory functioning of this psychic sieve. The more we can bring the adjustment of its meshes under voluntary control, the better will be our powers of concentration; whereas, if its mesh be loose or faulty, and we have acquired little or no control over it, we shall find that we are unable to hold our mind to any consecutive train of thought, and that our focus of consciousness is constantly liable to be invaded by ideas alien to the matter to which we wish to pay attention. These two levels, the FOCUS and FRINGE OF CONSCIOUSNESS, together comprise what is known as THE CONSCIOUS MIND. This is the part of the mind which most truly seems to be “our-self.” It is the section of the mind in which we carry on all our conscious mental activities, but it is by no means the whole of the mental house. Immediately behind the fringe of consciousness comes the level of the mind which is known as the FORECONSCIOUS, PRECONSCIOUS, and many other things according to the school of psychology whose doctrines are adhered to. If, however, its function be understood, it will be readily enough recognised through the disguise of the varied nomenclature which, unfortunately, complicates the study of psychology. In this level of the mind are stored all the ideas which we hold in memory, but are not actually thinking about. It may, in fact, be defined as the level of conscious memory, and just as the focus is separated from the fringe of consciousness by an adjustable censor-sieve, so an exactly similar sieve interposes between the fringe of consciousness and the foreconscious, and works upon exactly the same principles.