Abstract
Francesco di Giorgio (1439-1501) was one of the great architects in Renaissance architecture, known by his treatices which influenced later theorists and architects. In this paper, his motivation and method are tried to make clear, through the introduction of his own and others'manuscripts. His attitude to traditions, especially, to "authorities" was not to submit "reason" to them or to abandon it, but to permit and recognize them, based on the primitive exsistential and intentional way. On this point of view he was motivated to re-descrive Vitruvius's "De Architectur", criticizing his contemporary confusion in architecture. Therefore his method was to verify and interpret the greek and roman documents and ruins in order to identify "understanding" with "fact" or "truth".
