Dominicus De Clavasio

also known as Dominicus de Clavagio, Dominicus Parisiensis , or Dominic de Chivasso

(fl. mid-fourteenth century)

mathematics, medicine, astrology.

Dominicus de Clavasio’s birthdate is unknown, but he was born near Turin and was active in Paris from about the mid-1340’s. He taught arts at Paris during 1349–1350, was head of the Collège de Constantinople at Paris in 1349, and was an M.A. by 1350. Dominicus received the M.D. by 1356 and was on the medical faculty at Paris during 1356–1357. He was astrologer at the court of John II and may have died between 1357 and 1362.

Dominicus is the author of a Practica geometriae written in 1346; a questio on the Sphere of Sacrobosco; a Questiones super perspectivam; a set of questiones on the first two books of the De caelo of Aristotle, written before 1357; and possibly a commentary on Aristotle’s Meteorology. He mentions in the Practica his intention to write a Tractatus de umbris et radiis.

The questiones on the De caelo have not been edited, although a few that are concerned with physical problems have been examined. They reveal that Dominicus is part of the tradition established at Paris during the fourteenth century by Jean Buridan, Nicole Oresme, and Albert of Saxony. Like these Parisian contemporaries, he adopted the impetus theory as an explanation of projectile motion as well as of acceleration in free fall. Also like his colleagues at Paris, Dominicus considered impetus as a quality. As is true of the Questiones de caelo of Albert of Saxony, Dominicus” discussions of impetus reveal the influence of both Oresme and Buridan. If Dominicus were directly familiar with Oresme’s conceptions of impetus, he most likely drew them from the latter’s early Latin questiones on the De caelo and obviously not from his much later French Du ciel. According to Dominicus, a body in violent motion possessed both impetus and an “actual force” (virtus actualis), although the relationship between these factors is unclear. Also, as Nicole Oresme may have done, he may have connected impetus with acceleration rather than velocity.

The Practica was a popular work during the Middle Ages and has survived in numerous manuscript versions. It served, for example, as a model for a Geometria culmensis, written in both Latin and German near the end of the fourteenth century. The Practica is divided into an introduction and three books. The introduction contains arithmetical rules and the description of an instrument, the quadratum geometricum of Gerbert. Book I deals with problems of measurement, book II contains geometrical constructions of two-dimensional figures, and book III is concerned with three-dimensional figures. In the course of the Practica, Dominicus mentions Ptolemy and the thirteenth-century mathematician and astronomer Campanus of Novara.

The Questiones super perspectivam reveal Dominicus” familiarity with the standard authors of the medieval optical tradition, such as Witelo, al-Rāzī (Rhazes), Roger Bacon, Reckham, and Ibn al-Haytham (Alhazen). His work is not based, however, on the influential Perspectiva communis of Peckham but is a commentary on the De aspectibus of Ibn al-Haytham and the latter’s Latin successor, Witelo.

Insofar as his thought has been examined, Dominicus de Clavasio appears not as an innovator but as a fairly conventional continuator of well-established medieval traditions.

BIBLIOGRAPHY

I. Original Works. H. L. L. Busard, ed., “The Practica geometriae of Dominicus de Clavasio,” in Archives forHistory of Exact Sciences, 2 (1962–1966), 520–575, contains the entire text; Graziella Federici Vescovini, “Les questions de ‘perspective’ de Dominicus de Clivaxo,” in Centaurus, 10 (1964–1965), 14–28, contains an edition of questions 1 and 6.

II Secondary Literature. On Dominicus or his work, see A. von Braunmühl, Vorlesungen über Geschichte der Trigonometrie, I (Leipzig, 1900), 107–110; M. Cantor, Vorlesungen über Geschichte der Mathematik, II (Leipzig, 1899), 127, 150–154, 450–452; M. Clagett, The Science of Mechanics in the Middle Ages (Madison. Wis., 1959), pp. 635, 636, note; M. Curtze, “Über den Dominicus parisiensis der Geometria culmensis,” in Bibliotheca mathematica, 2nd ser., 9 (1895), 107–110; and “Über die im Mittelalter zur Feldmessung benutzten Instrumente,” ibid., 10 (1896), 69–72; G. Eneström, “Über zwei angebliche mathematische Schulen im christlicher Mittelalter,” in Bibliotheca mathematica, 3rd ser., 7 (1907), 252–262; Anneliese Maier, Zwei Grundprobleme der scholastischen Naturphilosophie (Rome, 1951), pp. 241–243; An der Grenze von Scholastik und Naturwissenschaft (Rome, 1952), pp. 121, 209; Metaphysische Hintergrunde der spätscholastischen Naturphilosophie (Rome, 1955), p. 365, note; and Zwischen Philosophie und Mechanik (Rome, 1958), p. 218; H. Mendthal, ed., Geometria culmensis. Ein agronomischer Tractat aus der Zeit des Hochmeisters Conrad von Jungingen, 1393–1407 (Leipzig, 1886), which contains the Latin and German texts of the Geometria culmensis; K. Michalski, “La physique nouvelle et les différents courants philosophiques au xiv^e siècle,” in Bulletin international de l”Académie polonaise des sciences et des lettres. Classe d”histoire et de philosophie, et de philologie (Cracow), année 1927 (1928), 150; P. Tannery, Mémoires scientifiques, V, J. L. Heiberg, ed. (Paris, 1922), 329–330, 357–358; Lynn Thorndike, A History of Magic and Experimental Science, III (New York, 1934), 587–588; The Sphere of Sacrobosco and Its Commentators (Chicago, 1949), p. 37; and E. Wickersheimer, Dictionnaire biographique des médecins en France au moyen âge (Paris, 1936), p. 121.

Claudia Kren