The building is made of grey stone, and it is this structural rigidity of the material that enables it, in the process of manufacture, to endure for a long time unscathed. Although every portion of the product is liable to fail catastrophically at any moment, if the connexion between its parts ceases to exist, this does not alter the essential difference between the product as a whole, and each individual product. The parts are therefore neither replaced nor reproduced in their natural form. They are replaced, as destructive forces in the process of production, by the product itself.