The Nature of Order: An Essay on the Art of Building and the Nature of the Universe () is a four-volume work by the architect Christopher Alexander published in 2002–2004. In his earlier work, Alexander attempted to formulate the principles that lead to a good built environment as patterns, or recurring design solutions. However, he came to believe that patterns themselves are not enough to generate life in buildings and cities, and that one needs a "morphogenetic" understanding of the formation of the built environment as well as a deep understanding of how the makers get in touch with the creative process. The Phenomenon of Life Volume 1 attempts to define "life" in the built environment and determine why one built environment may have more life than another. Important to this idea is his notion of centers: "Centers are those particular identified sets, or systems, which appear within the larger whole as distinct and noticeable parts. They appear because they have noticeable distinctness, which makes them separate out from their surroundings and makes them cohere, and it is from the arrangements of these coherent parts that other coherent parts appear. The life or intensity of one center is increased or decreased according to the position and intensity of other nearby centers. Above all, centers become most intense when the centers which they are made of help each other." Alexander argues that any entity (center) for example an ecosystem, landscape, garden, city, street, building, window, painting, animal or human being has a certain degree of life. According to Alexander, a human being is able to sense this degree of life in an entity objectively, as a real empirical dimension. He tries to demonstrate this to the reader with experiments that he has conducted, studies and experiments the reader can do. The ability to be aware of the degree of life of an entity, lays out the foundation for his theory and for the creative process of which human beings are, according to Alexander, capable. The first volume contains an exposition of what the author calls the fundamental properties, which are those that are possessed by environments which have more life. He argues that processes that lead to a good built environment are those that tend to increase one or more of these properties. He identifies fifteen geometric properties which tend to accompany the presence of life in nature, and also in