Christopher Alexander: Fifteen Transformations

” … the fifteen properties are not merely observable end-products of structure-preserving transformations. They provide the base transformations from which, in practice, all structure preserving transformations are made. The world of nature – what we think of as nature, and what we think of as natural (whether it is brought into being by the innocent operations of nature, or made carefully by the thoughts and hands of men and women) is that world which is brought into being by repeated application of these fifteen transformations, applied again and again, to enlarge, and deepen, and evolve, and magnify the beauty of the world which exists.”

Christopher Alexander – The Nature of Order – Book 2: The Process of Creating Life