He earlier wrote an influential paper "The Structure of Pattern Languages", which described the combinatorics of patterns necessary to use them effectively. This applies both to software and to architectural and urban design. In "A Theory of Architecture", Salingaros shows how a Pattern Language and a Form Language combine into an Adaptive Design Method. The discussion, while fairly abstract, digs at the scientific foundations of design, having more in common with Evolvable hardware than with the more philosophical discussions found in contemporary Architectural theory. The fractal mind The book discusses how the mind perceives and conceives architectural form, and postulates that fractal and other organizational mechanisms play a key role in perception. It then argues that humans naturally prefer fractal, organized structures, based on how the mind works. Most modern evolutionary biologists accept the idea that evolution is dependent on the geometry of the natural environment, and thus must be consistent with biological structure and morphology. However, the view that selection has shaped the mind to prefer certain shapes and configurations is more controversial. Geometrical fundamentalism The phrase "geometrical fundamentalism" in this book was coined by Michael Mehaffy and Salingaros as a provocative way of expressing the dominance of abstract, monolithic forms of Modern architecture. Being easy to build, the author claims that those simple typologies are passed on globally and now dominate world architecture. One of the strengths of the International Style was that the design solutions were indifferent to location, site, and climate. Nevertheless, by not allowing architectural form the freedom to adapt to a particular set of local circumstances, the built environment has tended further and further away from Sustainability. Meme encapsulation The book also coins the term “encapsulation” to describe an architectural meme bundled inside a social meme. The model suggests that such memetic replication models human culture, in which building and urban typologies proliferate for reasons other than their utility. The contention is that typologies that are passed on are the ones whose encapsulation is more appealing. Salingaros and Terry Mikiten propose that encapsulation helps an architectural meme to survive and reproduce. In particular, phenomena such as (possibly impractical) architectural fashions, where clients enable certain memes that do not promote mental health and feelings of wellbeing to reproduce, can be explained as encapsulations helping their enclosed memes to replicate. The converse is also true: an adaptive architectural typology, such as found in older vernacular architectures,