A Pattern Language, Christopher Alexander’s best known work, published in 1977, embraces this notion of variable agency in the built environment. Alexander presents 253 distinct patterns, each of which “describes a problem which appears over and over again in our environment, and then describes the core of a solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice.” These patterns range from street layouts to public space amenities to domestic furnishings. Importantly, they are sorted by scale and divided into three categories: towns, buildings, and construction.