All this means, in summary, that we are passing from the abstract to the concrete, from the meaningless to the meaningful, from the simple to the complex. We still keep to our scientific point of view, and we still employ our scientific method. The change is not in us, who are psychologising, but in our subject-matter; the plot begins to thicken; and this growing complexity of subject-matter naturally makes increasing demand upon our scientific resources. § 25. =The Analysis of Perception and Idea.=—Sensations and simple images can hardly occur, by themselves alone, in our everyday experience. The practised psychologist may be able to focalise a sensation, to make it so vivid that it stands out almost as it would under the experimental control of the laboratory; but his is an exceptional case. The units of our daily experience are rather such things as the sound of the piano in the next room, the sight of the tree budding just outside the window, the memory of last winter’s snow-piles, the forecast of to-night’s Pathetic Symphony; that is, they are _perceptions_ and _ideas_. Notice that they come to us in the first place as units, as wholes; they show no lines of natural cleavage; they are unitary and self-contained. Yet they are not psychologically simple; if they were, we should never have lit upon sensations and simple images. _All perceptions and ideas may be analysed._ A typical =perception= _resolves, to begin with, into a number of sensations_. The sound of the piano is, after all, the sound of certain compound tones, played together and in succession; and the sight of the tree is an arrangement of colours. The characteristic part of a perception, then, the part that we may conveniently call its core or nucleus, may thus be analysed into sensations. Only the core, however; for _the sensations are supplemented, secondly, by various images_. The sound comes to us as the sound of _the_ piano, the instrument of that familiar look; and we may have an imaginal hint of the child playing, of the score, of its special difficulties, of all sorts of related things. The tree, too, is _that_ tree, the familiar cherry that the caterpillars infest so badly, that grew so much last year, that will presently cut off the view across the street, that very likely will interfere with the beech. Remember that these are the author’s instances, and that you must replace them by your own! The point is that the complement of images is there; and you will notice that it is not stable; it may be full or scant, and it may lead the mind this way or that; but, whatever it be, it puts more into the perception than the sensory stimuli can account for; we perceive more than we hear or see.