REGIUS, HENRICUS (HENRI DE ROY)
(1598–1679)

Regius (Henri de Roy), a Dutch academic, was a major figure in disputes over Cartesianism in Utrecht, The Netherlands, during the seventeenth century. Regius received a medical degree from the University of Padua before returning in 1638 to his hometown of Utrecht to become a professor of medicine and botany at the university. Before his appointment there he gave private lectures based on the Dioptrics and Meteors, two of the essays published with René Descartes's Discourse on the Method (1637). What Regius found to be particularly congenial in these texts was the proposal there that observable phenomena be explained in terms of the mechanical properties of insensible material parts.

In 1641 Regius took advantage of his good relations with the new rector of the university, Gisbertius Voetius, to obtain permission to submit for discussion various "medical disputations." The first two disputations provide a mechanistic reinterpretation of Aristotelian notions, but in the third disputation Regius took the more aggressive tack of claiming that the union of the soul and body is not substantial, as the Aristotelians claimed, but accidental. Voetius responded with an appendix that defended Aristotelianism against the "new philosophy," and on the advice of Descartes, Regius offered a response that suggested that the Aristotelians had difficulty avoiding atheism. In 1642 the burgomasters of Utrecht ordered the confiscation of Regius's response and endorsed a statement by the faculty that condemned the teaching of the new philosophy. Descartes intervened by publishing attacks on Voetius in 1642 and 1644 that the burgomasters judged to be libelous. Fearful of imprisonment, Descartes sought the protection of the French ambassador, who succeeded in suppressing his arrest warrant.

To this point, Descartes had a favorable opinion of Regius. However, matters took a turn for the worse in 1645 when Regius sent Descartes a draft of his Fundamenta physices. Descartes was shocked by the assertion in one section of this text that it is impossible to prove that the soul is anything more than a mode of body. When Regius went ahead and published his text in 1646, Descartes denounced it in the preface to the French edition of the Principles (1647). A student of Regius published a broadsheet that highlighted Regius's rejection not only of a proof of immortality but also of innate ideas and the possibility of a proof of the existence of the material world. Descartes responded in 1648 with his Notes against a Broadsheet, and Regius replied that same year with his Brevis explicatio mentis humanae. Regius's text included a letter from Petrus Wassenaer defending Regius against the charge in the preface to the Principles that he had plagiarized portions of Descartes's unpublished treatise on animals. After Descartes's death Regius published second and third editions (1654 and 1661, respectively) of the Fundamenta physices with the new title Philosophia naturalis, in which he attempted to further defend the project of freeing mechanistic physics and physiology from dogmatic metaphysics, on which Descartes had attempted to found it. Regius's presentation there of the new science as a system of probable hypotheses is similar to the one found in the Traité de physique (1671) of the French physicist Jacques Rohault, perhaps the most influential defense of Cartesian physics in the century following Descartes's death.

See also Aristotelianism; Cartesianism; Descartes, René; Philosophy of Physics; Rohault, Jacques.

Bibliography

Dijksterhuis, E. J., et al. Descartes et le cartésianisme hollandais. Paris: Presses Universitaires de France, 1950.

works by regius

Fundamenta physices. Amsterdam: Elsevier, 1646.

Brevis explicatio mentis humanae sive animae rationalis … a Notis Nobil. Cartesii vindicata. Utrecht, Netherlands: N.p., 1648.

Philosophia naturalis. Amsterdam: Elsevier, 1654.

works about regius

Rothschuh, Karl E. "Henricus Regius und Descartes: Neue Einblicke in die frühe Physiologie (1640–1641) des Regius." Archives internationals d'Histoire des Sciences 21 (82–83) (1968): 39–66.

Verbeek, Theo. Descartes and the Dutch: Early Reactions to Cartesian Philosophy, 1637–1650. Carbondale: Southern Illinois University Press, 1992.

Verbeek, Theo, ed. Descartes et Regius: Autour de l'explication de l'esprit humain. Amsterdam: Rodopi, 1993.

Tad M. Schmaltz (2005)