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Cartesianism, experimentalism, and the experimental-speculative distinction

A guest post by Tammy Nyden and Mihnea Dobre.

Tammy Nyden and Mihnea Dobre write…

A while ago, we published an announcement on this blog of our forthcoming edited volume, Cartesian Empiricisms (Springer 2013). A claim in that post – that some Cartesians “seem to escape the ESD distinction” – has been questioned by Peter Anstey in another post. We thank him for the intervention and would like to push forward our claim and discuss it in more detail as this will reveal some of our concerns with the ESD (experimental-speculative distinction).

In his reply, Peter Anstey asked, “Did the Cartesians practise a form of experimental philosophy analogous to that of the Fellows of the early Royal Society?” We would argue that the question itself is problematic, as there are not two practices or worldviews to compare. There is variation among the Cartesians as well as among the fellows of early Royal Society.  In order to gain a nuanced understanding of these historical actors, we suggest a rather different question: “What role did Cartesian philosophy play in the acceptance and spread of experimental practices in late seventeenth-century philosophy?” When we ask this question, we recognize the experiments of Robert Desgabets on blood transfusion, Henricus Regius on liquids, Burchard de Volder’s with air-pumps, etc., and consider how their work improved experimental technologies, influenced a theoretical reflection on the role of experiments and the senses in natural philosophy, and influenced institutional change that was favorable to experimental science.

Because Cartesians took various aspects of Descartes’ system and merged it with various aspects of experimentalism, there is not one ‘Cartesian’ use of experiment, but several. For example, both Regius and de Volder promoted experiment, but Regius rejects Descartes’ theory of innate ideas while de Volder defends it. Many Cartesians came to reject hyperbolic doubt, some defended vortex theory, some did not. Cartesian Empiricisms is not a complete inventory of such views expressed by Descartes’ followers. Rather our goal was to encourage the discussion of the above-mentioned question and to reveal some aspects that have been unfortunately neglected so far by both historians of philosophy and science.

Readers of this blog are familiar with the objection that traditional historiography of science was built on the Rationalist-Empiricist distinction (RED). A consequence is the exclusion of so-called “rationalists” from the histories of science, particularly history of the use, development and acceptance of experiment. This is problematic because recent research (e.g., Ariew, Lennon and Easton, Easton, Schmaltz, Cook, Nyden, Dobre, etc.) shows that many so-called rationalists were deeply involved in the practice and spread of the acceptance of experiment in natural philosophy. Cartesian Empiricisms gives further emphasis to this issue, as it examines several philosophers who identified as committed Cartesians who were deeply involved in experiment. According to historiographies that divide the period into two mutually exclusive epistemologies or methodologies these philosophers either do not exist (i.e., they are overlooked by histories of philosophy and science) or are seen as “not really Cartesian” or “not really experimentalist,” as it would be needed by that particular narrative. Thus, we do share the concern of the authors of this blog, that such binaries as RED force us to fit philosophers into categories that they would not themselves recognize and causes us to misrepresent seventeenth-century natural philosophy. Moreover, we acknowledge that this blog importantly shows the anachronism of the RED, a way of viewing the period that is constructed later by what may be called Kantian propaganda. However, we would like to raise now some of our concerns with the distinction promoted by this blog, the experimental-speculative distinction (ESD) and explain why some Cartesians would escape the ESD. Our worries cover two important aspects of the ESD: the label “speculative” and the actor-category problem.

(1) In a very recent post, Peter Anstey argued that eighteenth-century Newtonians pointed out Cartesian vortex theory as a prime representative of speculative philosophy (our emphasis). We caution against letting eighteenth-century Newtonian propaganda color a historical interpretation of seventeenth-century natural philosophy. Voltaire, d’Alembert and others took great pains to contrast Newtonianism from Cartesianism as two mutually exclusive worldviews who battled it out, with Newton’s natural philosophy as the victor. But the reality is that after Descartes’ death (1650) and before the victory of Newtonianism in the middle of the eighteenth century, followers of both Descartes and Newton had more in common than we are led to believe. More importantly, both “camps” had more diversity than we were ready to accept in the traditional histories. Cartesian Empiricisms draws attention to that diversity within Cartesianism. Perhaps the one thing Cartesians discussed in the chapters of this volume do have in common is that they do both experimental and speculative philosophy, as these two categories are sometimes defined on this blog. But this last claim leads to our second concern with the ESD.

(2) A reader of this blog will find that when ESD is compared to RED, the first advantage highlighted over the latter is that “the ESD distinction provided the actual historical terms of reference that many philosophers and natural philosophers used from the 1660s until late into the 18th century.” While there is no doubt that many early modern philosophers were using this language (i.e., “experimental” and “speculative”) in their writings, it is equally true that such language is not in use by the Cartesians. If one would be very strict with picking up “the actual historical terms of reference,” one will see another pair of terms keep mentioned by various Cartesians, “experience” and “reason.” Of course, one can read this pair as another form of the ESD, but that would be an interpretation, and a problematic one at that. Both the Cartesians and the so-called “experimentalists” were trying to determine the proper relationship between reason and experience and when one looks at their attempts, it becomes even more difficult to draw a clear line between speculative philosophers and experimentalist philosophers.

Our concern is the possible danger of transforming ESD into a new RED. Experimental and speculative may be useful adjectives to describe aspects of a particular philosophy or particular commitments of a philosopher (especially when the two terms are clearly stated in one’s writings). However, they are not useful for dividing philosophers or their natural philosophies, particularly when they are not already conceived as falling within the “experimental philosophy” camp, as is the case for Cartesians at the end of the seventeenth century.

5 thoughts on “Cartesianism, experimentalism, and the experimental-speculative distinction

  1. Thanks for this post. We are interested in establishing exactly how widely the ESD was employed in the early modern period, not to pigeonhole philosophers, but to reconstruct the history of early modern experimental philosophy. To this end, it is useful to know that the Cartesians discussed in your collection cannot be adequately characterized as experimental or speculative. However, it does not follow that the ESD is not useful for dividing philosophers or natural philosophers. Do you take the ESD to be useless because you hold that all experimental philosophers were also, in one way or another, speculative? Or is there another reason for your claim?

  2. Thanks for your comment, Alberto. No one said that the ESD is useless. On the contrary, I find that many of the posts on this blog have convincingly shown that in some specific contexts the ESD is the best way to describe the natural philosophy of some seventeenth-century figures. However, this applies only to specific cases and what Tammy and I wanted to do in the post above was to share with you our concern that the ESD cannot be a general framework in which one should interpret philosophers (or their natural philosophies) in early modern period.

  3. Our claim is not that ESD is useless, it is a distinction that as your blog successively shows, was used by several early modern philosophers. To the extent that ESD is used to bring to light the distinctions those particular philosophers made, it is fine. Our caution is to go beyond that, and use it as an exclusive binary that can be used to divide all early modern natural philosophers. Our book shows that there are also many philosophers who did not use the distinction, nor to whom it would seem to apply as defined on this blog. Our concern is that a new binary might be seen to replace RED, thus again leading us to ignore philosophers who do not neatly fit into the new categories. Our argument is that in addition for looking for those that use such distinctions, it is useful to intentionally look for cases where the distinctions fall apart. Both approaches will show different aspects of the period and improve our understanding of early modern philosophy and the history of science.

  4. In response to your post, I’d like to make two clarificatory points about the experimental philosophers’ critique of Cartesianism, and in particular the Cartesian vortex theory. First, in my view, far from d’Alembert taking great pains to contrast Newtonianism and Cartesianism as two mutually exclusive worldviews, his potted history of experimental philosophy in the ‘Preliminary Discourse’ of the Encyclopédie was the first important attempt to draw a direct trajectory from Descartes to Newton.
    Second, with regard to Cotes’ critique of the Cartesians as speculative philosophers, there is a very real sense that by the time he drafted the Preface to the 2nd edition of the Principia, this was old news. At least since the early 1680s the Cartesian vortex theory had been labeled as speculative philosophy. Moreover, even before the emergence of experimental philosophy in the 1660s in England, Descartes’ natural philosophical methodology had been harshly criticized as speculative by William Petty.

  5. Thank you Peter for clarifying these two points. They are helpful. In this comment I shall refer only to your second point. I find Cotes’ claims about Cartesian philosophy as speculative to be rather late, because by the time when the second edition of Newton’s Principia is published, there are many other things going on in the background with respect to the relation between Cartesian and experimental philosophies. Perhaps the best example is the publication of Jacques Rohault’s Cartesian textbook on physics in a new Latin translation by Samuel Clarke. This textbook is particularly revealing for the context, as it comes in several editions with the text annotated by Clarke. I have discussed the reception of Rohault’s treatise in England in my contribution to the Cartesian Empiricisms, but it is worth stressing here that Cartesian physics is not presented as “speculative.” Moreover, despite his disagreement with some of the fundamental principles of Rohault – which are most of the time contrasted with Newton’s own principles – Clarke does not take any issue with Rohault’s method. For anyone interested in this, I have developed some of these points in a paper that is available here: