The document discusses various architectural theorists and their works from antiquity through the 19th century. It begins with Vitruvius and his treatise De Architectura from ancient Rome. It then discusses Indian treatises like the Mayamata, and the introduction of theory in the Renaissance with figures like Leon Battista Alberti and Andrea Palladio. It also touches on 18th and 19th century theorists like Laugier, Boullee, Ledoux, and Semper. Vitruvius is described as the most prominent architectural theorist from ancient Rome whose work has been hugely influential. The document also examines Leonardo Da Vinci's Vitruvian Man drawing and how it related proportions of the ideal human form to architecture