This example of Michelangelo's ceiling shows how, thanks to the rythmical nature of perception, art fulfils the mission of making us think from Shapes to Things and from Things back to Shapes. And it allows us to see the workings of that psychological law, already manifest in the elementary relations of line to line and dot to dot, by which whatever can be thought and felt in continuous alternation tends to be turned into a whole by such reiteration of common activities. And this means that Art adds to its processes of selection and exclusion a process of _inclusion,_ safeguarding aesthetic contemplation by drawing whatever is not wholly refractory into that contemplation's orbit. This turning of non-aesthetic interests from possible competitors and invaders into co-operating allies is an incomparable multiplying factor of aesthetic satisfaction, enlarging the sphere of aesthetic emotion and increasing that emotion's volume and stability by inclusion of just those elements which would have competed to diminish them. The typical instance of such a possible competitor turned into an ally, is that of the cubic element, which I have described (p. 85) as the first and most constant intruder from the thought of _Things_ into the contemplation of _Shapes._ For the introduction into a picture of a suggested third dimension is what prevents our _thinking away from_ a merely two-dimensional aspect by supplying subsidiary imaginary aspects susceptible of being co-ordinated to it. So perspective and modelling in light and shade satisfy our habit of locomotion by allowing us, as the phrase is, _to go into_ a picture; and _going into,_ we remain there and establish on its imaginary planes schemes of horizontals and verticals besides those already existing on the real two-dimensional surface. This addition of shapes due to perspective increases the already existing dramas of empathy, instead of interrupting them by our looking away from the picture, which we should infallibly do if our exploring and so to speak _cubic-locomotor_ tendencies were not thus employed inside the picture's limits.