Spinoza is often depicted as a solitary rebel. This is a caricature. In fact, he was one of a group of radical thinkers, deeply involved in the new science and in Cartesian philosophy, who gathered around Franciscus Van den Enden. Others included Lodewijk Meyer, Johan Bouwmeester, Pieter Balling, Simon de Vries, and Jarig Jelles. Spinoza participated with others in what was notorious as a Cartesian revolution, the mechanical philosophy. He, like his friends, was committed to determinism, the condition of human passivity, the intellectual love of God, and more.
The Principles of Cartesian Philosophy is the most explicit evidence of Spinoza’s interest and expertise in Descartes. One of two works published by Spinoza during his lifetime, it appeared in 1663. While living in Rijnsburg, Spinoza acted as a professional tutor, and one of his pupils in Cartesian philosophy was a nineteen-year-old Leiden University student, Johannes Caesarius. According to Spinoza’s friend Lodewijk Meyer in his introduction to the 1663 edition, Spinoza’s Amsterdam friends had encouraged him to publish the materials on Descartes that he had dictated to Caesarius. In them, Spinoza had recast Descartes’ philosophical thinking into a synthetic or demonstrative form both to clarify Descartes’ intentions and to secure the details of the system. The result is a work that reveals as much about Spinoza’s own thinking as it does about Cartesian philosophy. It was, after all, written on the heels of the TIE and during a period in which Spinoza was still at work on the Short Treatise, fully in the spirit of the rest of his philosophical and scientific enquiries.
Clearly Spinoza is convinced that mathematics is the exemplary science and that presenting philosophical results in a mathematical or geometrical form best reflects their certitude. Descartes’ Principles of Philosophy, published in 1644, was Descartes’ attempt to present in this form (that is, synthetically) the views he had come to in the 1630s—in the Meditations, Discourse, and essays on optics, astronomy, and geometry—in a more discursive or analytic way. Spinoza’s own presentation advances Descartes’ achievement. Originally it dealt with Part 2 of Descartes’ Principles and the beginning of Part 3. At his friends’ request, Spinoza added a presentation of Part 1. He did it rather quickly, however, and apologized for its haste.
Spinoza was explicit about Caesarius’ shortcomings, at least at this early stage in his education; he was after all only nineteen. For this reason, Spinoza studiously avoided discussion of his own views which he thought too advanced and for which Caesarius was not yet prepared. His comments on Part 1 and indeed the finished product were, in the end, prepared for his friends and associates and others attuned to the new philosophy. Ostensibly a work of pure exposition and clarification, the published book reveals some differences between Spinoza and Descartes as well as Spinoza’s way of clarifying the point of Cartesian philosophy and science. Like John Rawls’ account of Kantian moral philosophy, Principles of Cartesian Philosophy is about both its subject and its author.
When the work was published, Spinoza had already moved from Rijnsburg, near Leiden, to the village of Voorburg, outside The Hague. Shortly after the move, he visited Amsterdam for several weeks in order to prepare the lessons on Descartes for publication. Having spent two weeks writing his account of Part 1, he arranged Lodewijk Meyer’s assistance in editing the book and writing its preface. Eventually Spinoza appended some comments on the metaphysics of Part 1 and his own thoughts on these matters; these were published in an appendix, the “Cogitata Metaphysica,” or “Metaphysical Thoughts.” Meyer was careful in his preface to point out where Spinoza differed from Descartes—for example, on mind as a substance and on the freedom of the will. But Meyer was selective; there were many differences of organization and presentation as well as these central differences in substance.
The Principles of Cartesian Philosophy is an important document for a number of reasons. Spinoza’s exposition of Cartesian philosophy reflects his interest in the details of science as well as in its foundations. Second, his own “Cogitata Metaphysica,” when compared with his exposition of Part 1 and with his later work, expresses the primary role of God in his thinking and the importance of the modal notions of necessity and contingency and the concepts of eternity and duration. Finally, the work confirms Spinoza’s role as an expert in and advocate of Cartesianism and its special character as a model of the new philosophy.
M.L.M.