In the treatise, De re aedificatoria, Alberti sought to establish what was intrinsic to the art of building. It can seem that his over-riding concern was to establish its material and formal nature. However, architecture also figures in his other writings. Surveying the wider panorama of Alberti's thought, it becomes clear that what was extrinsic to architecture, yet crucial to its character, was of no less importance. Consistent with his emphatic naturalism, context was to be kept in view. And context extended from nature to society. His history of architecture values functionalism and his theory of its evolution begins with the material concerns of shelter and store. Yet, as architecture serves, it possesses a moral principle. Alberti, conceiving the conceptual, material, and social and moral object, co-opts metaphor as the means to describe the building under all these headings. So, ‘roof’ acquires resonant meaning, as do ‘hearth’, ‘table’, and so on – both elements and moral actions of house and church. When Alberti's language is recognized as functioning in this way, it acquires for the reader a singular animation. In Florence Cathedral he finds an exemplary case. A famous and problematic late text – describing Sant'Andrea in Mantua – can be acquitted of the charge of rhetorical insincerity.