The Timeless Way of Building is a 1979 book by Christopher Alexander that proposes a new theory of architecture (and design in general) that relies on the understanding and configuration of design patterns. Although it came out later, it is essentially the introduction to A Pattern Language and The Oregon Experiment, providing the philosophical background to the Center for Environmental Structure series.
It has had a huge influence on creative thinking, especially in the areas of architecture and software design.
In the book, Alexander introduces the concept of the quality without a name”