This chapter shows how Vitruvius developed his three fundamental categories within a naturalistic and empiricist conception of human life and perception. In the Renaissance, Leon Battista Alberti and Andrea Palladio, inspired by Neo-Platonism, took a more rationalistic, mathematical approach to beauty in their theories and their buildings. In the eighteenth century, the Scottish philosopher Lord Kames returned to Vitruvius's empiricist approach, while the French theorist Marc-Antoine Laugier, inspired by the aesthetic theory of Charles Batteux, identified beauty with the imitation of nature, but specifically with the identification of beauty with structural functionality.

This chapter considers linguistic and phenomenological approaches in recent architectural theory. It argues that the analogy of architectural language is imperfect, and any plausible use of it has to include semantic and pragmatic as well as syntactic dimensions. The phenomenological approach to architecture pioneered by Rasmussen and recently developed by Steven Holl in both his writings and his work has to take account of function and construction as well as the aesthetics of the experience of architecture.

This chapter argues both from the words and works of three twentieth-century masters, Frank Lloyd Wright, Adolf Loos, and Mies van der Rohe, that the Vitruvian values remained central to their architecture, for all the radical differences in style, materials, and technologies among their works and between their architecture and that of the Greco-Roman tradition. It also argues that for all the differences among these architects, the idea of freedom was central to their conceptions of the aesthetic appeal to architecture.

The Introduction uses the examples of two weekend retreats built four centuries apart by Andrea Palladio and Steven Holl to argue that for all their differences, both structures aim at good construction, functionality, and aesthetic appeal. The argument is amplified by consideration of a very different structure, a recycling plant designed by the contemporary architect Annabelle Selldorf. The cast of characters for the rest of the book are then introduced.

From Kant's "aesthetic ideas" to Ruskin's seven "lamps" of architecture, the Vitruvian conception of aesthetic appeal was expanded to include a range of intellectual and emotional content. Gottfried Semper shifted the discussion to the fundamental components of architecture – hearth, mound, roof, and walls – but what is done with these elements remains subject to the general goals of good construction, functionality, and aesthetic appeal.

This chapter considers the challenges facing contemporary architecture from factors including the economy, climate change, and social justice within the practice of architecture as well as within wider society. It discusses ways in which architects are meeting these challenges through adaptive reuse, sustainable construction, and innovations in planning and housing.

The 1786 review of Kant's Groundwork for the Metaphysics of Morals by Hermann Andreas Pistorius raised the objection that Kant's categorical imperative is an "empty formalism" that needs an antecedent conception of the good long before Hegel made the same charge in 1802.  Kant's explicit response to Pistorius in the Critique of Practical Reason is just to double-down on the priority of the right over the good.  However, I suggest that Kant's characterization of humanity as an end in itself as the "ground of a possible categorical imperative" in the Groundwork, on the one hand, and his account of the highest good as the complete object of morality in the second Critique, on the other, together provide a much fuller and satisfactory response to the "empty formalism" objection.