Ole Borch

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Ole Borch studied medicine (1644) at Copenhagen University, and attended lectures of the Cartesian Leiden professors Abraham Heidanus, Johannes de Raey and Adriaan Heereboord. He visited the entomologist Jan Swammerdam in Amsterdam (The Letters of Jan Swammerdam, 1975, pp. 5–6), and becaome professor of philology in Copenhagen (1660). A pioneer of experimental science, he authored De ortu et progessu chemiae dissertation, n.p. (Copenhagen, 1668) and Hermetis, Aegyptiorum et chemicorum sapientia ab Hermanni Conringii animadversionibus vindicata, Copenhagen, 1674. See: DBL, vol. 2, pp. 500–8; DSB, vol. 2, pp. 317–8; Jaumann, 2000, p. 122.

As a student in Leiden, Borch kept a lively diary in which he undertakes to give a detailed account of lectures he heard, encounters with learned men, and miscellaneous information on the sciences. Seemingly attracted towards all things novel and exciting, he also made notes about persistent rumours circulating with juicy gossip about radical Dutch free-thinkers and their ‘circles’. Borch made the acquaintance of a certain Höjerus. He not only told him about some of his own determinist theological views, but also put forward rumours about Cartesian atheists in Amsterdam. According to Borch’s account of his conversations of Höjerus, one of these Amsterdam atheists was a Jew, and it is virtually certain that he is hinting at Spinoza. Borch then writes in his travel diary: ‘[It is said that] there are some atheists in Amsterdam, but many of them are Cartesians, among them some Jew who is a shameless atheist’ (17 May 1661, Borch, 1983, vol. 1, p. 128). Personal contacts between Borch and Spinoza are undocumented. Yet, since Borch is reported to have lived under the same roof as Niels Stensen between February 1661 and May 1663, he doubtlessly made Spinoza’s acquaintance.

On September 10 and 24, 1661, Borch jotted two other accounts in his diary relating to Spinoza. The account the 24th also mentions his name and the fact that he resided in Rijnsburg. Borch wrote thus:

[That] Spinoza, a Jew turned Christian and now almost an atheist, lives in Rijnsburg; that he excels in Cartesian philosophy, that he even surpasses Descartes himself in all things, namely in distinct and probable concepts; that, however, many prefer by far Hudde in Amsterdam, who also published a small tract about furcation appended to Descartes’s last geometrical works.

Source: 24 September 1661, Borch, 1983, vol. 1, p. 228.


Alias: Olaus Borrichius.


Jan Swammerdam


Niels Stensen


Adriaan Heereboord


Abraham Heidanus


Johannes Raey, de