"What would concrete be, what steel, without plate glass? The ability of both to transform space would be limited, even lost altogether; it would remain only a vague promise. Only a glass skin and glass walls can reveal the simple structural form of the skeletal fame and ensure its architectonic possibilities. And this is true not only of large utilitarian buildings. To be sure, it was with them that a line of development based on function and necessity began that needs no further justification; it will not end there, however, but will find its fulfillment in the realm of residential building. Only here, in a field offering greater freedom, one not bound by narrower objectives, and the architectural elements forming the basis for a new art of building. They permit us a degree of freedom in the creation of space that we will no longer deny ourselves. Only now can we give shape to space, open it, and link it to the landscape. It now becomes clear once more just what walls and openings are, and floors and ceilings. Simplicity of construction, clarity of tectonic means, and purity of materials have about them the glow of pristine beauty."