This limitation to six points in certain positions certainly did not come about by chance. This can clearly be seen from the fact that a greater number, e.g. an arrangement of nine points as in Fig. III., would have greater practical advantages. By means of them it would have been possible for example to represent the most important punctuation marks or numbers with separate signs, a thing which is not possible in Braille's type for the blind. But such complications in the positions of the points are at once made useless by the fact that it is impossible clearly to grasp the difference of such a large number of points. Any one can convince himself of this by immediate observation, if he arranges more than six similar signs and tries to distinguish by touch alone. Thus we arrive again at the same limit that our metronome and optical experiments led us to. The importance of these results as to the scope of consciousness and of attention does not lie merely in the fact that we are able to state the relation of both in values that can be expressed in figures. Above all, our results give us an important insight into the relations between those elements that stand in the focus of attention and those that belong to the wider field of consciousness. In order, then, to denote clearly the most important results that have come to light in these experiments, let us use two short expressions for the two processes of the entrance into consciousness, and of the elevation into the focus of attention--two expressions that were first of all introduced by Leibnitz in a similar sense. We shall call the entrance into the large region of consciousness--apprehension, and the elevation into the focus of attention--apperception. We shall take no account of the philosophical meanings, in which Leibnitz uses these expressions in his theory of monads. We shall use these expressions purely in their empirical and psychological sense. Accordingly we understand by apprehension simply the entrance of some content into consciousness--an entrance that can be in fact proved, and by apperception the grasping of this by the attention. The apprehended content is that of which we are more or less darkly aware; it is always, however, above the threshold of consciousness. The apperceived content is that of which we are clearly aware, or, keeping to the figure of speech of a threshold, that which lies above the narrower threshold of attention. We can further define the relation between these two regions of consciousness. If the apperception is directed to one isolated element, the rest, the merely psychically apprehended elements, disappear as if they were non-existent. On the other hand, if the apperceived content is bound to certain merely apprehended elements of consciousness, it is combined into one total apprehension, which is only limited by the threshold of consciousness itself. In close relationship with this stands the