Johannes Lauratius De Fundis

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Johannes Lauratius De Fundis

(fl. Bologna, 1428-1473)

astronomy, astrology.

most of what we know about Johannes Lauratius (or Paulus) de Fundis is found in Thorndike, according to whom he is mentioned during most of the period 1428-1473 as lecturer in astrology at the University of Bologna. In April 1433 he observed Mars on several consecutive nights; and in the same year he published the first of his many writings, Questio de duracione. . . huius aetatis (MS Brit. Mus. Reg. 8. E. VII). Other works are Tacuinus astromico-medicus, a prediction dated 7 February 1435 (MS Bologna Univ. Libr. 2); Rescriptus super tractatum de spera, dated 1437 (M. S Paris, B. N. lat. 7273), a commentry on Sacrobosco; Questio de fine sec durabilitate mundi (a revised version of Questio duracione. . .), dating from 1445 (Ms Paris, B. N lat. 10271, 204r-227v); and Tractatus reprobacionis eorum que scripsit Nicolaus Orrem. . .contra astrologos, dated 30 Oct. 1451 (ibid., 63r & 153v), a defense of astrology against the antiastrological writings of Nicole Oresme.

Nova spera materialis, dated 10 Aug. 1456 (MSS Utrecht 724; Venice, San Marco VIII, 33), is a complete but brief exposition of astronomy, dealing with the system of the world, spherical astronomy, and planetary theory. Presumably it was written as an alternative to Sacrobosco’standard exposition. Finally, there is Nova theorica planetarum (incipit, “Theorica speculativa dicitur scientia motuum planetarum”), known from the same codices as Nova spera materialis but undated. It quores a treatise entitled De sphere rotunda, which seems to be identical to Rescriptus super tractatum de spera and accordingly must be later than 1437 but earlier than 1456, when the Utrecht MS was copied at Bologana. It is meant as a substitute for the thirteenth-century Theorica planetarum wrongly ascribed to Gerard of Cremona, Gerard of Sabioneta, and others.

The first six works in this list were examined by Thorndike, who determined that the author was an astrologer and astronomer of no exceptional equalities and without any outstanding ideas. Nova theorica planetarum is interesting only insofar as it reveals how planetary theory was taught around the middle of the fifteenth century at one of the major chairs of astronomy. It is almost contemporary with Peurbach’s famous work of the same title and exhibits many of the same features. Thus the geometric models of the old theorica (and the Almagest) are embedded in the system of “sphysical”s spheres known from Ptolemy’s Planetary Hyphotheses but are moved by separate “intelligences.” But where Peurbach maintains the Alfonsine theory of precession, Johannes is skeptical toward trepidation and prefers the Ptolemaic theory of a constant rate of precession. like the arabs, he is much intrested in coujuctions and in the initial conditions of the planetary system.


See L. Thorndike, History of Magic and Experimental Science, IV (New York, 1934), 232-242; O. Pedersen, “The Theorica Planetarum Literature of the Middle Ages,” in Classica et mediaevalia, 23 (1962), 225-232; and a roneotyped ed. of Nova theorica planetarum by O. Pedersen and B. Dalsgaard Larsen, “A 15th Century Planetary Theory” (Aarhus, 1961).

Olaf Pedersen

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Johannes Lauratius De Fundis

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