audible (and I may add intellectual or _verbal_) shape, has its appropriate accompaniment of emotional changes: the ease or difficulty of understanding producing feelings of victory or defeat which we shall deal with later. And although the various perceptive activities remain unnoticed in themselves (so long as easy and uninterrupted), we become aware of a lapse, a gap, whenever our mind's eye (if not our bodily one!) neglects to sweep from side to side of a geometrical figure, or from centre to circumference, or again whenever our mind's ear omits following from some particular note to another, just as when we fall asleep for a second during a lecture or sermon: we have, in common parlance, _missed the hang_ of some detail or passage. What we have missed, in that lapse of attention, is a _relation,_ the length and direction of a line, or the span of a musical interval, or, in the case of words, the references of noun and verb, the co-ordination of tenses of a verb. And it is such relations, more or less intricate and hierarchic, which transform what would otherwise be meaningless juxtapositions or sequences of sensations into the significant entities which can be remembered and recognised even when their constituent sensations are completely altered, namely _shapes._ To our previous formula that _beautiful_ denotes satisfaction in contemplating an aspect, we can now add that an _aspect_ consists of sensations grouped together into _relations_ by our active, our remembering and foreseeing, perception. CHAPTER VI ELEMENTS OF SHAPE LET us now examine some of these relations, not in the genealogical or hierarchic order assigned to them by experimental psychology, but in so far as they constitute the elements of _shape,_ and more especially as they illustrate the general principle which I want to impress on the Reader, namely: That the perception of Shape depends primarily upon movements which _we_ make, and the measurements and comparisons which _we_ institute.