What might be meant by the phrase “architecture and philosophy”? I distinguish what it might mean from three other possibilities, “philosophy of architecture,” “philosophy as architecture,” and “architecture as philosophy.” The first refers to a subfield of academic aesthetics, itself a subfield of academic philosophy; the second to the use of architectural metaphors in philosophical writing; the third to the idea that works of architecture should express abstract, philosophical ideas. I discuss the pitfalls in the last of these. Instead, I argue, going back to Vitruvius, that the phrase “architecture and philosophy” should be taken to connote the architect’s obligation to satisfy through her building (firmitas) the program for her work, thus the client’s and users’ needs (utilitas) as well as aesthetic considerations (venustas), but beyond that to be sensitive to all ethical issues broached by her work and to have an understanding of the way or ways of life in which her work and its use will become involved.”