Is the phenomenon of postmodernism in architecture and planning a matter of superficial style, or does it represent something more fundamental? What kind of style is postmodernism, and what kind of style should postmodernism be? This paper offers answers to these questions by referring to a comprehensive theory of aesthetics as a basis for evaluating postmodernism. This theory is sketched out and then postmodernism is defined by comparison with modernism. A fundamental split within postmodernism is delineated; the postmodernism of reaction is characterized by empty formalism, while the postmodernism of resistance involves a critical appreciation of the various elements of local context. The theory of aesthetics, although only rudimentary, provides obvious support for the postmodernism of resistance, or critical regionalism.