Yes, and we perceive more than is furnished us by sensations and images. It is a fact (which you will better understand presently) that _every perception is shaped and moulded by the action of nerve-forces which show themselves neither in sensation nor in image_. The nervous system, whether by racial heritage or by individual habit, meets its impressions halfway, and throws them into certain customary forms. We take both the tree and the piano to be real things, and we take them to be things that occupy real space; we perceive them as objects of the outside world, and we perceive them as solid or space-filling. We do this because we have a natural and ingrained tendency to cast our perceptions into the forms of ‘thing’ and ‘space’; and this tendency of the nervous system does its work automatically; it has no correlate of sensation or image; but it is none the less effective, so to say, _behind_ the sensations and the images, in determining the perception. You must just accept this statement now; it will become clearer later on. A typical =idea=, in the same way, _has a core or nucleus of images_. Last winter’s snow may come to us in many different ways, because our equipment of images is very variable (pp. 75 f.); it will come to most, perhaps, as a visual picture, an uneven spread of white, with streaks of grey-brown on the peaks and along the valleys, honeycombed and broken from some partial thaw. To-night’s music will come, possibly, as the sound of the opening adagio measures, or of some theme from the allegro. Here again, however, the nucleus has its surroundings; _other images cluster about it_; we recall the day so-and-so got his feet wet, or the big fall of that December Thursday; we see our place in the concert-hall, or hope that this time the tympani will be in tune. _Nor is the idea altogether a matter of images._ We can hardly think of those opening measures without kinæsthetic sensations from the throat, or from some muscular beat of the rhythm; we can hardly think of getting our feet wet, or of seating ourselves in the hall, without some actual movement that arouses sensation. Find your own instances, once more, and do not trust the author! You will find that _the typical idea is thus in part sensation, just as the typical perception is in part image_. Finally, the idea, too, is subject to the pressure of the _directive nerve-forces_; it takes the same customary forms as the perception. Columbus is thought of as a real person, acting in a real world of space and time; and Zeus as an imaginary person in an imaginary world; but there is no difference in the form of the ideas, and no difference of form between these ideas and the perception of the stranger who has just passed the window.