The glow of grime Of course this 'sheen of antiquity' of which we hear so much is in fact the glow of grime. In both Chinese and Japanese the words denoting this glow describe a polish that comes of being touched over and over again, a sheen produced by the oils that naturally permeate an object over long years of handling—which is to say grime. If indeed 'elegance is frigid', it can as well be described as filthy. Jun'ichirō Tanizaki & Thomas J. Harper, In Praise of Shadows timeaestheticsfilthflaws
Changing constraints The Constraints Keep Changing The explicit listing of known constraints in the design program helps here. The designer can periodically scan the list, asking, “Can this constraint now be removed because the world has changed? Can it be entirely circumvented by working outside the design space?” Frederick P. Brooks, Jr., What's Wrong With This Model? What's wrong with the rational model constraints