Danti, Ignazio

Title Le due regole della prospettiva pratica...
Imprint Rome, F. Zanetti, 1583
Localisation Getty Research Institute, NC749.V5 1583er
Subject Perspective
Transcribed version of the text


     The mathematician Ignazio Danti (1536-1586) produced this treatise. He disclosed to the public the architect Vignola’s rules of perspective which had remained unpublished. A few leaves of this manuscript are kept in the archives of the Accademia di San Luca in Rome. Danti was a member of this academy. However, this is not simply a transcription, an edition with comments of the two rules; Dante wrote a real teaching manual of geometry intended for figurative artists and an encyclopedia of the contemporary practices of perspective construction. This work came subsequent to Daniel Barbaro’s treatise (1568) which was a first attempt at looking at the methods which rendered perspective in the light of the practices then in use.
     The first edition saw the light of day in Rome in 1583, at the presses of Francesco Zanetti, ten years after Vignola’s death. It was followed by numerous reprints up until the middle of the 19th century, the period which also corresponds to the end of the domination of perspective in representating space. In the 17th century, several translations were made in French and Castilian but remained in manuscript form. There were many partial copies and demonstration plates circulating in the workshops. It was republished in 1974, 1985 and 2007. A modern French translation came out in 2003.
     The work is made up of a theoretical part and a practical part. It opens on a definition of perspective which bases mathematics as “the soul and spirit which give form and existence to the arts of drawing”. Straightaway Danti asks the question of mimesis; nevertheless he then develops the distinction between imitating vision and that of the process of seeing. In his opinion, perspective is a tool as productive as it is cognitive. He then presents the vocabulary and the notions he uses. This part gives him the opportunity to clarify elementary notions of optics, geometric and anatomical. Then come geometric instructions, in the form of theorems where the reader is invited to draw for himself the figures as the exposé is being developed. These theorems are mainly taken from Euclid and are, in his opinion, useful in practicing perspective. Useful but not indispensable; this is the major educational asset of Danti’s treatise, to manage to suggest various thought processes according to his readers’ expectations. Some would judge it necessary to “know the reasons for things”, others “who are not interested in demonstrations, will be able to be content with the way to proceed”.
     In order to have people understand better that theorems are nothing other than the translation of reality, he does not fail to show the balance between theory and practice. For example, he simultaneously displays the possibility of determining geometrically the progressive reduction of grid references according to distance and the experiment conducted by Tommaso Laureti with a specific instrument. Danti, a professor of mathematics at the University of Bologna, came from a family of artists and all his life collaborated with artists. His theoretical approach was strongly marked by this experience.
     Vignola’s first rule falls within the province of Alberti’s modo optimo. It is based on the intersection of the visual rays of the pyramid with the picture plane, and its implementation makes explicit the geometric aspects of the seeing process. Danti shows that this rule is the wording of the procedure that Dürer undertook with his drawing frame. Danti presents other improved variants of this instrument, used by artists and mathematicians. He adds particular cases, like Baldassare Lanci’s instrument which measures the points necessary for a drawing in perspective on a concave surface. Vignola’s second rule uses a distance point. It is more difficult to understand but quicker to use and permits one to draw complex subjects dependably. In spite of its more conceptual character, it is, according to its author Vignola, “the most excellent among all”. From what Danti says, nevertheless, the rule which is used the most often is the one he associates with Baldassare Peruzzi, which also resorts to the distance point. It was also put forward by Serlio (1545) and used by Antonio da Sangallo. It is a very simple rule necessitating few procedures and limiting drawings and measurements.
     In addition to these three rules making up his objective, Danti introduces a great variety of rules and methods which give his book a unique character: several false rules which he saw being used in the studios, the particular method of rendering perspective, the sottoinsù, called squaring elsewhere, the method for painting in perspective on ceilings, painting periakton in perspective for theater design, anamorphoses and other particular questions. Frequently, he puts forward descriptions and commentaries on contemporary works. For each one of the rules, Danti grants particular attention to the literature preceding it and points out how the procedures he sets out are products of 15th and 16th century cultures. He cites and comments on those coming before him; he shows clearly the differentiation and continual movement among the theoretical principals, mathematical propaedeutic and artistic practice. His work is not only the most complete one written on perspective during the Renaissance, it is also the one which achieved the greatest legacy.

Pascal Dubourg Glatigny (Centre national de la recherche scientifique,
Centre Koyré, Paris) – 2015

Critical bibliography

E. Danti, Les deux règles de la perspective de Vignole, translation by P. Dubourg Glatigny, Paris, CNRS editions, 2003.

F. Diaz Moreno, “De arquitectura y perspectiva: Felipe Lázaro de Goiti, traductor de Barbaro y Vignola-Danti ”, Anales de Historia del Arte, 2003, 13, p. 191-210.

P. Dubourg Glatigny, “Egnatio Danti as the founder of the authentic theory of artistic perspective as compared to late Renaissance ideas on the authenticity of texts”, South African Journal of Art History, 19, 2004, pp. 48-68.

P. Dubourg Glatigny, Il disegno naturale del mondo: Saggio sulla biografia di Egnatio Danti con l’edizione del Carteggio, Perugia, 2011 (with the bibliographical description of all the republications).

F. Fiorani, “Danti Edits Vignola: The Formation of a Modern Classic on Perspective”, Studies in the History of Art, 59, 2003, pp. 127-159.

J. Kuhn, “La buona squola di Badassare: Vignola’s Due Regole as a source for Peruzzi’s perspective techniques”, C. L. Frommel et al. (eds.), Baldassarre Peruzzi (1481-1536), Venice, Marsilio, 2005, pp. 411-442.

P. Roccasecca, “Per una storia del testo de ‘Le due regole della prospettiva pratica’ ”, R. J. Tuttle, B. Adorni, C. L. Frommel, C. Thoenes (eds.), Jacopo Barozzi da Vignola, Milan, Electa, 2002, pp. 367-372.

P. Roccasecca, “La ‘Portione del manoscritto originale diGiacomo Barozzi da Vignola della sua propposettiva’ ”, R. J. Tuttle, B. Adorni, C. L. Frommel, C. Thoenes (eds.), Jacopo Barozzi da Vignola, Milan, Electa, 2002, pp. 372-377.

P. Roccasecca, “Danti e le due regole”, C. L. Frommel, M. Ricci, R. J. Tuttle (eds.), Vignola e i Farnese, Milan, Electa, 2003, pp. 161-173.