Theodorus Ryckius

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Theodorus Ryckius matriculated as a student (1660) of literature and philosophy in Leiden. He was rector of the Latin School in Kampen. He was professor of history and eloquence in Leiden (1672–90), and had a large correspondent network (Epistolae ineditae, 1843). He published the notes and corrections of the Vatican librarian Lucas Holste (1596–1661), on the work of Stephanus Byzantinus (1684), and the complete works of Cornelius Tacitus (1687). See Van der Aa, 1852–78, vol. 16, p. 604.

In a letter to Oldenburg of late 1675, Spinoza refers to rumours circulating about the upcoming publication of his Ethica (cf. 1675.[8–10].00, Ep 68). He also informs his London correspondent that several theologians had alarmed the stadholder and the magistracy about the treatise. Strong suggestion that disquietous individuals indeed notified contacts high-up about the work can be found in a letter of Ryckius dated 14 August 1675. That letter is addressed to one of his regular correspondents, Adriaen Adriaensz van Blijenburg.The Dordrecht patrician was deeply embedded in networks of ruling politicians in The Hague, and from an early stage, he had been a faithful supporter of William III. One of the subjects raised in Ryckius’s letter to Van Blijenburg is the persistent rumour about the upcoming printing of Spinoza’s Ethica, but it remains further unclear who was the source of that delicate information. Ryckius informs his correspondent that ‘the author of Tractatus Theologico Politicus’ wants to publish a book ‘on God and Reason’. There is no doubt, he states, that such a book is even much more dangerous than his first work which had also ravaged the Dutch Republic by openly undermining ‘our holy belief’. Ryckius therefore urgently asks Van Blijenburg to remain vigilant and use his political power and that of his ruling friends to stop the book form being published: 

There is a rumour among us that the author of ‘Tractatus theologico-politicus’ is about to issue a book on God and the mind, one even more dangerous than the first. It will be up to you and those who, with you, are occupied with governing the Republic, to make sure that this book is not published. For it is incredible how much that man, who has striven to overthrow the principles of our most holy belief, has already harmed the Republic.

Source: Epistolae ineditae, 1843, p. 6.

It is unknown if and also what the latter answered Ryckius and whether he was in any way involved in the decision to stop the posthumous writings in the placard against it that was issued on June 25, 1678.


Henry Oldenburg


Benedictus Spinoza, de


Adriaen Adriaensz Blijenburg, van