Lumières et Vision: Reflections on Sight and Seeing in Seventeenth- and Eighteenth-Century France

Lumières et Vision: Reflections on Sight and Seeing in Seventeenth- and Eighteenth-Century France Virginia E. Swain T HE PHILOSOPHY of the eighteenth century, in the words of Michel Foucault, took as its founding myths “ the foreign spectator in an unknown country, and the man born blind restored to light.” 1 These two mythical experiences can be referred in turn to developments in optics which occurred during the preceding 100 years. In fact, if the eighteenth century chose to name itself “ le Siècle des Lumières,” it was really the seventeenth century which made light and sight fashionable areas of scientific research and recurrent figures in literary and philo­ sophical works. The rapid succession of discoveries in the field of optics, which grew from a rudimentary science at the beginning of the 17th century to one of the most advanced of all sciences in Newton’s time, greatly contributed to the fascination with sight and seeing which dominated both the 17th and the 18th centuries. Speculation about how human beings see, which had been debated at least since Empedocles, culminated during this period in the work of Johannes Kepler, who in 1603 discovered the diop­ tric mechanism by which the eye forms an image.2Because he was careful to treat vision as a purely physiological (rather than a psychological or philosophical) problem, insisting that “ the eye operates as an optical instrument like any other,” 3Kepler “ brought about in the seventeenth century a systematic recognition of the different kinds of questions involved in the phenomena of the animate and sensitive body” (Crombie 66). His work opened the door to experimental science, in which scien­ tific observations preceed hypotheses, and suggested questions concern­ ing the psychology of perception which would be treated in the eigh­ teenth century by the likes of Locke, Berkeley, Diderot and Condillac. Concurrently with these developments in the understanding of vision, scientists of the early 17th century were making major technical advances in optics and ophthalmology. The most important of the early break­ throughs was the refinement of lenses, which made telescopes practical and microscopes possible. Galileo’s improved telescope enabled him to confirm Copernicus’ theory that the planets turned around the Sun, not VOL.XXVIII, N o.4 5 L ’E sprit C réateur the earth. Whereas Copernicus had been readily dismissed in his time as extravagant, the publication of Galileo’s Sidereus Nuncius in 1610 shook the foundations of popular belief in an earth-centered universe, organized according to hierarchies whose main source was the Scrip­ tures. The next year, Kepler’s Dioptrice explained the optical principles of the telescope, and the instrument became an accepted scientific tool.4 It did not take long for the new worlds which the telescope revealed to fire the popular imagination: in 1686, the narrator of Fontenelle’s widely-read Entretiens sur la Pluralité des Mondes was already dreaming with his female companion about the possibility of inhabited planets in the far reaches of the solar system. The creation and popularization of that other magnifying instru­ ment, the microscope, followed logically from the development of the telescope. Galileo, Kepler and Descartes were all interested in micro­ scopy: Galileo occasionally used his telescope as a microscope, albeit an ungainly and inefficient one; and Kepler’s proposals (in his Dioptrice) for a compound microscope with convex lenses in the eyepiece resulted in the instrument which bore his nam e.5The pioneering research of Antonij van Leeuwenhoek (1632-1723) was known and admired throughout Europe—he had been publishing his observations since 1673 in the Royal Society’s Philosophical Transactions, and through the intermediary of Constantin Huygens his work was presented to the Académie des Sci­ ences in 1679; later an edition of his letters was the subject of two long “ comptes rendus” in the Bibliothèque universelle et historique (no. 537), April 1686 and August 16866 —and it contributed greatly, along with Robert Hooke’s Micrographia (1665), to the tremendous interest in microscopes in the late 17th and early 18th centuries. Despite the crude­ ness of the early microscopes’ optical systems, the instrument made possible significant advances in anatomical science and particularly in the understanding of the generation...