Correspondence to and from an author can be an invaluable aid to the reconstruction of his life and the understanding of his thought. So it is with Spinoza’s letters. Although the political and ecclesiastical persecution of the time led the original editors of the Opera Posthuma—his friends Lodewijk Meyer, Georg Hermann Schuller, and Johannes Bouwmeester—to delete personal matters and to disregard letters of a personal nature, the letters we have do help to understand Spinoza’s biography. And many include important questions about issues of philosophical, theological, and scientific interest and Spinoza’s responses to those questions. Without the correspondence, the depths of Spinoza’s life and thought would be much more obscure indeed.
The correspondence spans the years from 1661 to 1676 and includes letters to and from a variety of correspondents. The Opera Posthuma (O.P.) contained seventy-four letters in the Latin edition of 1677. The collected works published by J. Van Vloten and J. P. N. Land in 1882 added ten letters and ordered them chronologically; their numbering has become standard. The Gebhardt edition of 1925 added two letters, 30a and 67a, thus bringing the currently accepted total to eighty-six letters.
The period 1661–1665 includes an important correspondence between Spinoza and Henry Oldenburg, who became secretary of the Royal Society in London in 1662. Among the letters is Spinoza’s lengthy discussion of Robert Boyle’s treatise on nitre, which Oldenburg had sent to Spinoza (Ep6), and Spinoza’s critique of the experimentalism that underlay Boyle’s mechanical philosophy. Other letters deal with God, attributes, and additional metaphysical matters, as well as questions about knowledge. In 1665 Spinoza outlines to Oldenburg his reasons for writing a treatise on Scripture and what Oldenburg calls his views on “angels, prophecy and miracles.” Later that fall, on 20 November 1665, Spinoza writes to Oldenburg about parts and wholes and, using the metaphor of a tiny worm living in the blood, he clarifies how and why he holds that both the human body and the human mind are parts of Nature. After a hiatus of about ten years, the correspondence with Oldenburg is revived in 1675 and 1676 and includes a heated discussion of the Theological-Political Treatise, Spinoza’s views expressed in it and in his Ethics, and the implications for moral and religious life.
Oldenburg was a friend, though not as personal or close a one as men like Simon de Vries, Lodewijk Meyer, Pieter Balling, Johan Bouwmeester, and Jarig Jelles. There are letters to and from these more intimate friends as well, dealing with a range of topics. Among them is the famous and important letter “on the infinite” (Ep12), written to Meyer on 20 April 1663. In later years Spinoza came to know Ehrenfried Walther von Tschirnhaus, a German aristocrat studying in Leiden and a person familiar with philosophers and scientists throughout Europe. Their correspondence of nine letters, between 1674 and 1676, discussed, among other topics, the important issue of free will and causal determinism, an issue also treated in the correspondence with Georg Hermann Schuller, the Amsterdam physician who may have introduced Spinoza to Tschirnhaus.
The letters not only cover a wide range of issues and engage a variety of correspondents, from close friends to acquaintances; they also differ in tone and detail. Often Spinoza is asked to clarify or defend himself. In his letters to John Hudde, an Amsterdam friend interested in optics and an elected political official, he discusses the proofs for God’s necessary existence (Ep34–5). The correspondence with J. Louis Fabritius, professor of theology and philosophy at Heidelberg, concerns the offer to Spinoza to teach at that university and his refusal in 1673 (Ep47–8). These letters are respectful and businesslike. Different in tone are the letters from Alfred Burgh and Nicholas Steno, old friends, who wrote to Spinoza in 1675, seeking to convert him to Roman Catholicism, as they themselves had been converted. There is an aggressiveness and edge to these exchanges not present in the more collegial letters among other friends, a tension characteristic too of the earlier correspondence of 1664–1665 with the grain merchant Willem van Blyenbergh, about God, anthropomorphism, and human freedom (Ep18–24).
The technicality and abstractness of Spinoza’s philosophical work have a crystalline power that keeps his personality at a distance. The letters give us access to Spinoza as a man and the concrete reality of his life and work. The Letters confirms what shows through his work only at moments—his personal character and his humanity.
M.L.M.