It is, of course, well known that in all normal acts of visual perception the eyes do not observe the world with a blank, unmoving stare. On the contrary, they observe by continually scanning the visual field in a series of movements to and fro, and making continuous adjustments of focus. Without this optical movement, and the muscular sensations which accompany it, we should have no proper appreciation of space. And where drawing is concerned it seems quite clear that the movements suggested by the traces of the drawing-point ought actually to guide the motions of the eyes. The eyes must follow the original movements of the point—all of them, in due scale of emphasis—if one is to grasp the drawing properly. One adopts the mental scanning-pattern which the artist originally set down. One learns thus, by assimilation, advanced scanning procedures from artists whose own highly developed performances have been recorded by their drawing-points. So drawing is seen to be one of the most important elements in educated the eye and in developing visual perception—itself a matter of visual concepts and habitual structures. [...] This again is one of the reasons why it matters so much for us to be able to discern in a drawing the original rough laying-out strokes by which the artist first located his image on the surface. They are an integral part of the scanning-pattern which will give to our perception the totality of the image. [...] In fact it is well known that excessive 'completeness' or 'finish' can be more injurious to a drawing than to any other kind of art.