"A hollowed-out space in living rock is a totally different environment from a building constructed of quarried stone. The human organism responds in each case with a different kind of empathy. Buildings are fashioned in sequence by a series of uniformly repeatable elements, segment by segment, from a foundation upwards to the conjunction of walls and roof; the occupant empathizes with a visible tension between gravity and soaring tensile strength. Entering a great building is to experience an almost imperceptible tensing in the skeletal muscles in response to constructional tension. Caves, on the other hand, are scooped out by a downward plunge of the chisel from ceiling to floor in the direction of gravity; the occupant empathizes with an invisible but sensed resistance, an unrelenting pressure in the rock enveloping him; sculpted images and glowing pigments on the skin of the rock well forth from the deeps. To enter an Indian cave sanctuary is to experience a relaxation of physical tension in response to the implacable weight and density of the solid rock."