  After some years of instructing pupils in philosophy and theology, Gassendi distanced himself from what he believed to be rigid teachings of the Scholastics in his Exercitationes Paradoxicae of 1624. Thereafter he began a formative partnership in physiological, astronomical, and historical studies with the wise and wealthy Peiresc, summarized in Gassendi's glowing biography written upon Peiresc's death in 1637. By this time, Gassendi had also developed his early interests in a variety of questions in basic physics and in restoring the philosophy of Epicurus—much as Thomas had restored Aristotle, integrating his thought with what he held to be theologically viable. His published work in philosophy and natural philosophy captured the attention of the Minim priest, Marin Mersenne. Gassendi spent the last two decades of his life traveling back and forth between Provence and Paris because of varying commitments to patrons, appointment to the College Royal, and ill health. Throughout, he remained informed of and involved with scholarly discussions of the day, owing to his engagement with the group of philosophers and scientists united through correspondence with Mersenne. In the Mersenne circle, debates ranged over numerous topics central to the dismantling of Aristotelian and Scholastic world-views, and Mersenne often used his role as facilitator to bring together opponents on these issues. In that context, Mersenne helped enable the entry of Gassendi's criticisms of Descartes's Meditations into the Objections and Replies (Gassendi subsequently published his rebuttals in his Disquistio Metaphysica of 1646) and focused Gassendi's attention on refuting the mystical attacks on Kepler by Robert Fludd (Epistolica Exercitatio, in qua principia philosophiae Roberti Fluddi medici reteguntur, 1630). Members of this circle regularly reported on each other's experiments and proposed new challenges, such as Poysson's well-known puzzling over whether physical indivisibles could or should be identified with mathematical points. Gassendi used this forum to learn about other empirical studies as well as to work out a good many of his views.