Upon our knowledge of the precise stage of such pictorial development depends our correct recognition of what things, and particularly what spatial relations and locomotion, of things, the painter is intended to represent. Thus when a Byzantine draughtsman puts his figures in what look to us as superposed tiers, he is merely trying to convey their existence behind one another on a common level. And what we take for the elaborate contortions of athletes and Athenas on Sixth Century vases turns out to be nothing but an archaic representation of ordinary walking and running. The suggestion of locomotion depends furthermore on anatomy. What the figures of a painting are intended to be doing, what they are intended to have just done and to be going to do, in fact all questions about their action and business, are answered by reference to their bodily structure and its real or supposed possibilities. The same applies to expression of mood. The impassiveness of archaic Apollos is more likely to be due to anatomical difficulties in displacing arms and legs, than to lack of emotion on the part of artists who were, after all, contemporaries either of Sappho or Pindar. And it is more probable that the sculptors of Aegina were still embarrassed about the modelling of lips and cheeks than that, having Homer by heart, they imagined his heroes to die silently and with a smirk. I have entered into this question of perspective and anatomy, and given the above examples, because they will bring home to the reader one of the chief principles deduced from our previous examination into the psychology of our subject, namely that _all thinking about things is thinking away from the Shapes suggesting those things, since it involves knowledge which the Shapes in themselves do not afford._ And I have insisted particularly upon the dependence of representations of locomotion upon knowledge of three-dimensional existence, because, before proceeding to the relations of Subject and Form in painting, I want to impress once more upon the reader the distinction between the _locomotion of things_ (locomotion active or passive) and what, in my example of the _mountain which rises,_ I have called the _empathic movement of lines._ Such _movement of lines_ we have seen to be a scheme of activity suggested by our own activity in taking stock of a two-dimensional-shape; an _idea,_ or _feeling_ of activity which we, being normally unaware of its origin in ourselves, project into the shape which has suggested it, precisely as we project our sensation of _red_ from our own eye and mind into the object which has deflected the rays of light in such a way as to give us that _red_ sensation. Such _empathic,_ attributed, movements of lines are therefore intrinsic qualities of the shapes whose active perception has called them forth in our imagination and feeling; and being qualities of the shapes, they inevitably change with every alteration