Spinoza: Scientist and Theorist of Scientific Method

Abstract

Two questions concern me in this paper. First, what is the place and importance of Spinoza's work as a practising scientist? Second, what did Spinoza think were the right rules to follow in carrying out specific scientific investigations? I Coupling these two questions will, I believe, throw some new light on Spinoza's work and thought. Our second question will occupy the larger part of this paper, since the answer depends upon Spinoza's theory of the necessary inadequacy of the human mind and our almost total ignorance of how things are "linked together in the universal system of nature (totiusque naturae ordinem et cohaeren-tiam)" (Tractatus Theologico-Politicus, Gebhardt III, p. 191). In order to focus the discussion of the second question, I will introduce it by pointing to an apparent contradiction in what Spinoza wrote concerning the study of the emotions. In a well known passage in the Ethics he appears to take an a priorist stand, while in an echoing passage in the Tractatus Politicus he appears to take an empiricist position. The resolution of this apparent contradiction is central to an understanding of Spinoza's theory of scientific method. First, then, what is the importance of Spinoza's work as a practising scientist? Let me consider the evidence, item by item. In his correspondence with Boyle, via Oldenburg, Spinoza described some chemical and physical experiments he had undertaken. The experiments appear to have been ad hoc, conducted in order to examine critically the work that Boyle had done. There is no evidence that Spinoza was interested in carrying on a continuing program of chemical and physical experimental research. The experiment on pressure described in Letter XLI (Gebhardt IV, pp. 202-206) to Jelles likewise appears to have been carried out in order to reply to a question that Jelles had asked "first by word of mouth and then in writing". Spinoza was an expert lens grinder and a student of optics. He was on the periphery of Huygens's circle, and in his letters Huygens showed considerable respect for Spinoza's knowledge and practical skill in 95 Marjorie Grene and Debra Nails (eds.), Spinoza and the Sciences, 95-123.