Commentary on Juval Portugali's ‘Bohm's theory of orders as a basis for a unified urban theory’

Portugali's proposal to unify urban theory based on Bohm's theory of quantum phenomena is discussed. The propositions of complexity theory and phenomenology are compared, and it is argued that their ontologies and epistemologies cannot be easily reconciled. It is argued that Bohm's theory is compatible with complexity theory but does not help bridge the differences between complexity theory and phenomenology. A grand unification of urban theory, the way Portugali envisions it, does not seem to be possible.