Memory is an essay that has been developed on the occasion of the X Forum ProArch, National Scientific Society of Architectural Design teachers, SSD ICAR 14-15-16, held in Genoa, on 16-17-18 November 2023. The way in which memory, a faculty linked to elapsed time, to the past, relates to and contributes to architectural design, that is instead entirely aimed at the future, constitutes one of the most profound and fascinating relationships within architecture. This relationship intrinsically involves, as is typical of this discipline, numerous knowledge and fields of study, psychology, philosophy, art, history, applied sciences. Memory, as our ability to conserve and update information and materials, plays a fundamental role both in the phase following the production of the project and the work, as it allows the definition and transmission of shared knowledge (technical and more broadly cultural), which equally in the very phase of conception and elaboration, in the conscious, scientific relationship, with the technical baggage of necessary acquired knowledge but also in an admirable way in the phase more linked to intuition, less rational and controllable, of imagination and prefiguration, so to speak creative. Memory represents that thin thread, or rather that network of threads, which makes the link of continuity between the past and the future possible and concrete; it is therefore both an instrument and a material and process, which lives, transforms and acts in continuous evolution. . Even more generally, memory, whether individual or collective, is the faculty that allows us to develop, and through which, living is expressed in its most general characteristics. The text will develop these themes by declining them into a broad reflection, through examples relevant to various fields but always with reference to the broad nature of the architectural project, typical of its episteme.