Being projected, in the absence of anchoring points, by the attitude of my body alone, as in Nagel's experiments specified, when the body is inert, through the demands of the spectacle alone, as in Wertheimer's experiment it normally makes its appearance where my motor intentions and my perceptual field join forces, when my actual body is at one with the virtual body required by the spectacle, and the actual spectacle with the setting La Structure du Comportement,.