ARTICLE SE NIHIL DATURUM –DESCARTES’S UNPUBLISHED JUDGEMENT OF COMENIUS’S PANSOPHIAE PRODROMUS (1639) Jeroen van de Ven and Erik-Jan Bos * The municipal archives of The Hague hold a small collection with personal papers of the Leiden physician Cornelis van Hogelande (1590–1662). Among Van Hogelande’s papers we found the copies of two letters by his close friend Rene´ Descartes. The first letter is without question the most important discovery: the letter was completely unknown and contains Descartes’s unpublished judgement on a work by the Czech reformer Jan Amos Comenius. 1 Both copies lack an address, but there can be no doubt that the original letters were sent to Van Hogelande, because the second of the two letters was – for the greater part – already known and can be found in the standard edition of the correspondence by Adam and Tannery (AT III, 721–4). Addressed to Van Hogelande on 8 February 1640, it contains Descartes’s judgement on a broadsheet by the English mathematician John Pell. 2 However, compared to the text published in AT, the copy in The Hague has an additional paragraph. Moreover, in it Descartes refers to the *We wish to thank the Gemeentearchief in The Hague for the kind permission to publish the letters of Descartes. We are much obliged to John Cottingham who readily agreed to translate the Latin letters into English. We also thank Theo Verbeek for his helpful comments on earlier drafts of this article. The edition of Descartes’s works by Charles Adam and Paul Tannery (Paris: Vrin, 1964–74) is abbreviated AT. The Correspondance du P. Marin Mersenne (Cornelis de Waard, et al. (eds), Paris: PUF/CNRS, 1945–86) is abbreviated CM. AT and CM are followed by volume and page number. The abbreviation CSMK is used for The Philosophical Writings of Descartes, vol. III, The Correspondence, trans. by John Cottingham, Robert Stoothoff, Dugald Murdoch and Anthony Kenny (Cambridge: Cambridge University Press, 1991). 1 Johannes Amos Comenius (1592–1670) was the last bishop of the Reformed Church of Moravia. As a philosopher and theologian he expanded his educational and pansophic ideas, building a large network of relations with many intellectuals, like Hartlib. Comenius published mainly on universal wisdom (Pansophiae prodromus, 1639; Conatuum pansophica- rum dilucidatio, 1644) and education (Labyrint, 1623; Opera didactica, 1657–58; Janua linguarum reserata, 1633). See Milada Blekastad, Comenius. Versuch eines Umrisses von Leben, Werk und Schicksal des Jan Amos Komensky (Oslo: Universitetsforlaget, 1969); Daniel Murphy, Comenius. A critical reassessment of his life and work (Dublin: Irish Academic Press, 1995). 2 The English mathematician John Pell (1611–85) worked on algebra and number theory but never published anything substantial in the field. Being a member of the Hartlib circle (see British Journal for the History of Philosophy 12(3) 2004: 369–386 British Journal for the History of Philosophy ISSN 0960-8788 print/ISSN 1469-3526 online ª 2004 BSHP http://www.tandf.co.uk/journals DOI: 10.1080/0960878042000253060