Through the analysis of some of his most emblematic works, this monograph offers an approach to Sert the designer, quite a challenge considering that he was the architect who taught us to live without furniture. Using numerous texts, articles, and illustrations, the author allows us to glimpse the personality of this man of prominent public stature, a renovator of architectural language, a defender of the importance of the environment, climate, and landscape, and therefore an exponent of a vision of modernity with a distinctly humanist character.