Also, on this proposal, all modalities are in the same boat. As such the disposition theory is more ambitious than most of the theories already discussed, which are limited to vision. Not only is there no reduction of perceptual spatial content to a “muscular vocabulary”, there is also no reduction of the spatial content of some perceptual modalities to that of one or more others—as there was for Berkeley, who sought to reduce the spatial content of vision to that of touch, and whose program forced a distinction between two spaces, visual space and tangible space: