Decoding Luigi Moretti's Architettura Parametrica presents an unprecedented critical discussion of one of the earliest theoretical and practical explorations into the integration of scientific thought, mathematical models, and digital tools in architectural design. Moretti, a renowned professional who engaged in countless intellectual initiatives, developed and refined his architectural vision long before "parametric" became synonymous with computational design. His Architettura Parametrica is an unconventional inquiry of the prospects offered to design practice by digital thinking rather than by digital tools, which were still immature or completely absent at the time. Moretti proposed a unique and still relevant mental landscape that united his fascination with Baroque spatiality, operational research, informal art, optics, cybernetics, ethics, and much more. This research decodes numerous facets of Architettura Parametrica, from the rigid theoretical precepts to the negotiation with design praxis, from the use of equations to aid the research of forms to the speculation on the meaning of architecture through abstract mathematics. This book offers novel perspectives to scholars interested in the interplay between architectural design practice and theory, mathematics and design methods, digital and architectural culture, and to the growing number of practitioners who are crafting personal narratives within the most disruptive computational techniques.