This lecture will center on the largely forgotten architectural work of Gustavo Giovannoni (1873–1947), who promoted a scientific approach to architectural restoration and rehabilitation based on the simultaneous consideration of the historical, technical, environmental, social, and aesthetic dimensions of "monuments" and ordinary buildings. From his base in Rome, Giovannoni urged the education of the "complete architect" — or the "architetto integrale" — who would be multidisciplinary, practical designers capable of advancing an integrated vision of the city in all its spatial and temporal dimensions. I have recently coedited and published the first English-language translations of several of Giovannoni's most significant writings, which provide many crucial lessons about how to conserve and how to build anew to advance ideals of beauty, sustainability, and social justice. The lecture will be organized around key concepts in Giovannoni's conservation theory: the need for understanding all kinds of urban buildings, a respect for the physical and social context of architecture, a thinning out of the urban fabric (what he called "diradamento"); the grafting of the new upon the old (what he called "innesto"); and other conservation/rehabilitation treatments. Giovannoni's lessons pertain to many contemporary architectural and planning challenges here in Ithaca as well as in wider global contexts.