Architects have produced many manifestos on what constitutes good architecture. The earliest was Vitruvius’s De architectura: libri decem. Some subsequent treatises (for example, those of Alberti, Gropius and Venturi) have shaped architects’ thinking but most have fallen by the wayside. Other architects and their clients have failed to embrace their prescriptions. Clients too have aspirations that need to be recognized. The chapter begins with a discussion of the values of the various clients for architectural services. The powerful and wealthy have predominated. Some, like their architects, have been pragmatists, others have been empiricists and yet others, rationalists. Both clients’ and architects’ ideas have been influenced by competing pressure groups’ advocacies for specific ends to be met.