It seems that, _in most cases, the state of attention is_ =twofold= _and only twofold_. There is a cluster of sensations at the centre, all of approximately the same vividness, and there is a mass of sensations in the background, all of approximately the same obscurity. Suppose that you are looking at one of the puzzle-pictures that are published in certain magazines,—trying to find a face outlined in the branches of a tree. At first, the whole picture is vivid, and the rest of your experience is obscure. Suddenly you find what you are seeking; and what happens? In all likelihood, the picture drops with a jerk into the general dimness of the background, while the face that you have discovered stands out by itself in all imaginable vividness; you forget the picture, and see nothing but the face. The state of attention, then, in this its usual form, may be represented by two concentric circles; a small inner circle stands for the focus of attention, a large outer circle circumscribes its margin. There is experimental evidence that, when our sensations are thus arranged, their vividness and obscurity are, as the arithmetics say, inversely proportional; _the more vivid the central processes, the more obscure are the marginal_; or, in untechnical language, the more we are concentrated upon any one thing, the less liable are we to distraction by other things. This twofold arrangement seems to be, for most of us, the regular pattern of attention; but certain observations in the laboratory, which are borne out by statements in various text-books of psychology, make it practically certain that _there is another, less frequent and more complicated type of arrangement_. Here the picture does not drop clear down into the background, when the face is found, but remains poised somewhere between focal vividness and marginal obscurity; so that three degrees of vividness—sometimes even four have been reported—may be distinguished in one and the same state of attention. In such cases, attention must be represented by three or four concentric circles; the inner and the outer still show the focus and margin of the total state; the others indicate that there are sensations present whose vividness lies somewhere between those extremes. Whether the focal processes suffer from the rivalry of the moderately vivid sensations; whether, that is, attention in its threefold or fourfold pattern is necessarily, even at the best, of a lower degree than the best attention of the twofold kind, we do not know.