(b. Paris, France, 16 September 1666; d. Paris, 26 September 1716)
Parent was the son of an avocat au conseil. His mother’s uncle, Antoine Mallet, took charge of the boy’s education when he was only three; Fontenelle, our source for this information, does not indicate why the father relinquished the duty. An elderly and pious man, Mallet pointed Parent toward a career in law. After dutifully completing that study, Parent turned to mathematics, for which he had independently acquired a taste. He attended the lectures of La Hire and Sauveur—the latter considered Parent a rare genius. For a short time Parent accompanied the Marquis d’Alégre on military campaigns, studying fortifications, and then devoted his time exclusively to science.
In 1699, when Gilles Filleau des Billettes was elected to the Académie des Sciences, he selected Parent as his élève. Parent carried the title until his death. His failure to advance was due to a lack of clarity in his writing, his antipathy to Cartesian science, and his aggressive, tactless, critical, and uncompromising candor in dealing with colleagues. Fontenelle declared that he had “goodness without showing it “, scarcely a generous remark in an official eulogy. Parent, who never married, lived alone according to an austere, disciplined regimen. In 1716 he contracted a fatal case of smallpox.
Parent’s interests were very wide-ranging, although such broad scope was not uncommon in his day, before the branches of science were carefully delineated. He wrote on astronomy, cartography, chemistry, biology, sensationalist psychology and epistemology, music, practical and abstract mathematics, and various mechanical phenomena, particularly those of the strength of materials and the effects of friction on motion. He often reviewed and commented on the works of others. He read many papers to the Académie des Sciences but few were published in the Mémories. His most frequent avenues of publication were the Journal des sçavans and the Journal de Trévoux. In 1705 he launched his own periodical, Essais et recherches de mathématiques et de physique, which, although short-lived, provided a means of publishing much of his completed work. A three-volume sequel (1713) remains his best-known and most comprehensive collection.
Some of Parent’s work was clearly original. The work of 1705 contained a memoir, originally delivered to the Academy in 1700, on the description of a sphere according to the techniques of analytic geometry. Although the treatment is awkward by modern standards, the clear understanding and use of space coordinates was not to become routine for many years. Typically, Parent aimed at extending the power both of geometry and of the new calculus, although he was far from moving to pure analysis. Some of his earliest work was in cartography, and it seems to have left a permanent mark on his style. The ever-present correspondence between the descriptive device of geometry and the physical space being described is characteristic of mapping. Parent never went the full journey to pure abstraction. He anticipated neither Lagrange nor Laplace but, rather, Coulomb, the engineer who absorbed enough science to emerge as an early physicist. The similarity is confirmed in Parent’s work. The early study of fortifications has been mentioned. The publication of 1713 included an article describing the conditions of stress on a loaded beam, in which Parent first recognized the existence of a shear stress. Certain aspects of the analysis were not extended or even repeated for over half a century, by Coulomb.
Parent’s contributions to science are not best characterized by the listing of “firsts”. The power of the new mathematics was such that originality became common during the first decade of the eighteenth century. Parent learned from La Hire and Sauveur, and he shared the stage during his prime with Varignon, Hermann, Jakob I Bernoulli, and others. If Parent had a particular characteristic, it is perhaps his sense of the practical. The utilitarian aspect, seldom absent in his work, is noticeable from his first paper, on the calculation of frictional forces in machines, to his last, on the theoretical and practical applications of arithmetic.
Also remarkable is the degree to which Parent’s criticisms of scientific work extended into the thematic or paradigmatic foundations of science. This tendency is evident even in the first volume of the 1713 publication; the bulk of that book is devoted to an attack on Descartes’s Principia philosophiae, a work then nearly seventy years old. Parent went through it almost paragraph by paragraph; the reviewer in the Journal des sçavans needed three pages just to list the points upon which Parent and Descartes disagreed. For Parent, who was an atomist, motion could not produce hardness in objects, nor could it account for their specific shapes; Cartesian laws of motion were entirely incorrect. Parent refuted Cartesian notions on the formation of the elements, on comets, weight, the nature and effects of fire, on air, winds, hail and lightning, subterranean heat, light and color, the nature of ideas and the principles of music. Parent did not, as might be suspected, consider Newton to be Descartes’s principal adversary, although Parent and Newton clearly shared many concepts. But Parent and seems to have viewed Descartes as having been refuted by the whole range of seventeenth-century mechanical philosophers who embraced atomism. His attack on Descartes seems also to have been aimed at the Academy, most of whose members still clung to Cartesian science.
Parent emerges from the skimpy historical record as rather stiff, pious, solitary, independent, hardworking, and intelligent. He foreshadowed the Enlightenment in his unflagging critical spirit, his attempt to develop the scientific view of nature, and his conviction that the seemingly esoteric nature of mathematics had a very real utility.
I. Original Works. Parent’s most comprehensive single work is Essais et recherches de mathématiques et de physique, 3 vols. (Paris, 1713). Also valuable are his reviews and articles in the Journal des sçavans and the Journal de Trévoux.
II. Secondary Literature. Parent has not received much attention. His official éloge by Fontenelle appeared in the Histoire de l’Académie Royate des Sciences for 1716 and constitutes the bulk of the available biographical information. An account of his mathematics can be found in C. B. Boyer, History of Analytic Geometry (New York, 1956), 156 ff. The most extensive treatment of his physics is in Clifford Truesdell, The Rational Mechanics of Flexible or Elastic Bodies, in Euler’s Opera omnia, 2nd ser., XL, pt. 2 (Lausanne, 1950), 109–114. Truesdell repeats some of his comments in “The Creation and Unfolding of the Concept of Stress, “in Essays in the History of Mechanics (New York, 1968), 184–238. See also C. S. Gillmor, Coulomb and the Evolution of Physics and Engineering in Eighteenth-Century France (Princeton, 1971), passim; Isaac Todhunter, A History of the Theory of Elasticity and of the Strength of Materials (New York, 1960), passim; and Hunter Rouse and Simon Ince, History of Hydraulics (New York, 1963), passim.
J. Morton Briggs Jr.