Schmarsow'sarticulationof spatialcreationin architecture, like other late-nineteenth-centuryattemptsto expressa
knowledgeof artin the terminologyof science, depended conceptuallyon earliertheoriesof psychologicaland physi- ological optics.9 George Berkeley'sessay on optics of 1709 establisheda paradigmof experientialor associationalper- ception that would exercise a profoundinfluence on all subsequenttheorists.0 His argumenthinged on the prob- lem that we observethree-dimensionalobjectswith a pair of eyes that can only recordvague two-dimensionalpat- ternsof light and color. He assertedthatdistanceand form cannot be apprehendedwith the eyes alone; to form men- tal images of distance and magnitude requiresthe faculty of touch. Perception of visual space, then, resultsfrom the combination of memories of touch (tactile ideas) with immediate visual sensations.