Born in Huy (near Liège) and educated at Louvain (Collège du Faucon) and the Liège Seminary, Reneri was destined for the priesthood. However, he converted to Calvinism and fled to Leiden, where he pursued his theological studies at the university. After a period as private tutor, he became professor of philosophy at the Illustrious School of Deventer in 1631. In 1634 he exchanged this position for a professorship in philosophy at Utrecht, where he died five years later. Descartes must have known Reneri right from the beginning of his stay in the Netherlands, in 1629. Not only did they become intimate friends, but Reneri was instrumental in creating Descartes’ Dutch network. Unlike Mersenne, he seems to have done that with great discretion (there were even complaints that he was shielding Descartes from the outside world). Although Reneri was a great admirer of Descartes, he was not a Cartesian. A Baconian of sorts (in Utrecht he pleaded for the appointment of an official fact-collector, who would go to Amsterdam and interrogate mariners and artisans) and involved with the Hartlib Circle, he seems to have been fairly traditional and eclectic in his teaching. In fact, his position is difficult to assess given the fact that, apart from a dozen disputations, he did not leave any writings. The funeral address at his death, written and pronounced by the professor of history Antonius Aemilius (1589–1660), derailed into an excessive eulogy of Descartes and caused something of a scandal.

See also Calvinism; Mersenne, Marin; Regius, Henricus