Editing René Descartes (section)

==== France ====
In 1620, Descartes left the army. He visited [[Basilica della Santa Casa]] in Loreto, then visited various countries before returning to France, and during the next few years, he spent time in Paris. It was there that he composed his first essay on method: ''Regulae ad Directionem Ingenii'' (''[[Rules for the Direction of the Mind]]'').<ref name="Durandin"/> He arrived in [[The Hague|La Haye]] in 1623, selling all of his property to invest in [[Bond (finance)|bonds]], which provided a comfortable income for the rest of his life.{{sfn|Gaukroger|1995|page=132}}<ref name=":8" />{{Rp|94}} Descartes was present at the [[siege of La Rochelle]] by [[Cardinal Richelieu]] in 1627 as an observer.<ref name=":8">Shea, William R. 1991. ''The Magic of Numbers and Motion''. Science History Publications.</ref>{{Rp|128}} There, he was interested in the physical properties of the great dike that Richelieu was building and studied mathematically everything he saw during the siege. He also met French mathematician [[Girard Desargues]].<ref>{{Cite book |last=Aczel |first=Amir D. |url= |title=Descartes's Secret Notebook: A True Tale of Mathematics, Mysticism, and the Quest to Understand the Universe |date=2006-10-10 |publisher=Crown |isbn=978-0-7679-2034-6 |pages=127 |language=en}}</ref> In the autumn of that year, in the residence of the papal [[nuncio]] [[Giovanni Francesco Guidi di Bagno|Guidi di Bagno]], where he came with [[Marin Mersenne|Mersenne]] and many other scholars to listen to a lecture given by the alchemist, Nicolas de Villiers, Sieur de Chandoux, on the principles of a supposed new philosophy,<ref>Matton, Sylvain, ed. 2013. ''Lettres sur l'or potable suivies du traité De la connaissance des vrais principes de la nature et des mélanges et de fragments d'un Commentaire sur l'Amphithéâtre de la Sapience éternelle de Khunrath'', by Nicolas de Villiers. Paris: Préface de Vincent Carraud.</ref> Cardinal [[Pierre de Bérulle|Bérulle]] urged him to write an exposition of his new philosophy in some location beyond the reach of the Inquisition.<ref>Moote, A. L. 1989. ''Louis XIII, the Just''. [[Oakland, California|Oakland]]: [[University of California Press]]. [https://books.google.com/books?id=ya0wDwAAQBAJ&pg=PA271 pp. 271–72] {{Webarchive|url=https://web.archive.org/web/20210816214232/https://books.google.com/books?id=ya0wDwAAQBAJ&pg=PA271 |date=16 August 2021 }}.</ref>