Le due regole della prospetiva pratica is a book by the Italian renaissance architect Giacomo Barozzi da Vignola (1507 – 1573) and the Dominican monk and polymath Egnatio Danti (1536 – 1586). The book deals, as the title indicates, with two different approaches to perspective drawing and teaches them to the reader in a step-by-step manner. It was published ten years after Vignola’s death, in 1583, with detailed comments by Danti who reflects on Vignola’s thoughts and drawings on perspective.
The two rules treated in the book are called the “centric point system” or “costruzione legitima” by Alberti and the “distance point method”. According to Vignola the two rules are equally valid and will in the end produce the same result but follow different principles and procedures.
The book is divided into two parts, one for each regola. Each of the chapters has a prefixed part in which the author gives the reader a few hints and definitions for a better understanding of the book “Delle definitione che s’hanno à usare in questa seconda regola”
I chose the concept of illustrations because throughout the book, the concepts that are explained in text, are always accompanied by some sort of an illustration, either a simple geometrical sketch or a shaded perspective drawing, however the later are much less frequently used. My personal favorite drawing can be found on page 83 and shows a shaded section of a dome.
Furthermore I noticed that in the first part of the book (chapter about the prima regola and a chapter in which he writes about “Della regola ordinaria di Baldassare da Siena e del Serglio), there are a lot more simple geometrical sketches, each of which precisely explained by Danti, who describes every Point and each straight line. Whereas in the chapter about the seconda regola the illustrations tend to be of a larger format.
“Not until the publication of Jacopo Barozzi da Vignola’s Le due regole by Egnatio Danti in 1583 was there an illustrated explanation of the ostensible difference and correlation between Alberti’s centric point system and the distance point method.” (Massey, L. (2003) Configuring Spatial Ambiguity: Picturing the Distance Point from Alberti to Anamorphosis. Studies in the History of Art Vol. 59, Symposium Papers XXXVI: The Treatise on Perspective: Published and Unpublished: pp. 160-175)
The illustrations are therefore an especially important aspect of the book, as Vignola was the first one to graphically demonstrate the concept of perspective drawing in an illustrative manner.
Massey, L. (2003) Configuring Spatial Ambiguity: Picturing the Distance Point from Alberti to Anamorphosis. Studies in the History of Art Vol. 59, Symposium Papers XXXVI: The Treatise on Perspective: Published and Unpublished: pp. 160-175.
Fiorani, F. (2003) Danti Edits Vignola: The Formation of a Modern Classic on Perspective. Studies in the History of Art Vol. 59, Symposium Papers XXXVI: The Treatise on Perspective: Published and Unpublished: pp. 126 – 159
Kitao, T. (1962). ‘Prejudice in Perspective: A Study of Vignola’s Perspective Treatise’. The Art Bulletin, vol. 44, no. 3: 173-194.