His universe of instruments is closed and the rules of his game are always to make do with 'whatever is at hand,' that is to say with a set of tools and materials which is always finite and is also heterogeneous because what it contains bears no relation to the current project, Or indeed to any particular project, but is the contingent result of all the occasions there have been to renew Or enrich the stock or to maintain it with the remains of previous constructions or destructions