Here is how he defines it:
>There is a central quality which is the root criterion of life and spirit in a man, a town, a building, or a wilderness. The quality is objective and precise, but it cannot be named.
This concept of QWAN lies at the core of his theory of architecture and urban design.
The claim of a spirit-based meaning in all things is a radical departure from the previous rational framework of architecture. This old framework, based on a Cartesian Mindset, resulted in architecture that was functional but, for many, spiritually vapid and de-humanizing.
In a three volume set, Alexander sought to redefine architecture based on the wisdom of traditional spaces, found in pre-industrial villages and cities. By doing so, he layed the groundwork of what came to be known as New Urbanism a model that has helped guide the rejuvenation of our urban areas.