Leibniz’s early reflections on natural history and experiment
Peter Anstey writes…
G. W. Leibniz visited England in late October 1676. While there he renewed his acquaintance with Henry Oldenburg, Secretary of the Royal Society, and showed him his calculating device. After a week’s visit he boarded a ship bound for the Continent on 29 October, but for various reasons the ship was delayed and he used his time while moored in the Thames to write a dialogue about the nature of motion.
This dialogue, recently translated in full for the first time, has a very interesting preamble about natural philosophical methodology. This preamble may well have been stimulated by his recent visit to London, for it mentions some of the leading ideas of the new experimental philosophy that was practised there and promoted by many Fellows of the Royal Society of which Leibniz was a foreign member.
The dialogue is between Pacidius, aka Leibniz, Gallantius, Theophilus and Charinus. Pacidius opens with a comment about the danger of looking for causes when one does natural history. (I am quoting from the translation of Richard Arthur, G.W. Leibniz: The Labyrinth of the Continuum: Writings on the Continuum Problem, 1672–1686, New Haven: Yale University Press, 2002.) We take it up from Gallantius’ reply:
GALLANTIUS: I have certainly often wished that observations of nature, especially histories of diseases, could be presented to us unadorned and free from opinions, as are those of Hippocrates, and not accommodated to the opinions of Aristotle or Galen or somebody more recent. For we will only be able to revive philosophy when we have solid foundations for it. (p. 133)
Gallantius focuses on natural histories of disease, but his point applies more generally to the project of Baconian natural history (described here) which, as Oldenburg repeatedly claimed, was to provide solid foundations for natural philosophy. Theophilus replies:
THEOPHILUS: I do not doubt that the royal road is through experiments, but unless it is levelled out by reasoning we will make slow progress, and will still be stuck at the beginning after many generations. (p. 133)
Theophilus here raises the issue of the relation between the gleanings from observation and experiments, which is the focus of natural history, and the need to theorise in order to get an understanding of nature. The comment about being ‘stuck at the beginning after many generations’ is prescient because, as we have pointed out before on this blog, one of the reasons that the Baconian program of natural history faltered in the late seventeenth century was because it had delivered so little in the way of stimulus to new natural philosophy. Robert Hooke was sensitive to this very point in his ‘Discourse of Earthquakes’:
tho’ the things so collected [by our natural historians] may of themselves seem but like a rude heap of unpolish’d and unshap’d Materials, yet for the most part they are so qualified as that they may be fit for the beginning, at least of a solid, firm and lasting Structure of Philosophy. (Posthumous Works, London, 1705, p. 329)
Theophilus continues:
… I am amazed at how many excellent observations we have …, at how many elegant experiments the chemists have performed, at what an abundance of things the botanists or anatomists have provided, which philosophers have not made use of, nor deduced from them whatever can be deduced.
PACIDIUS: But there does not yet exist a technique in natural philosophy for deducing whatever can be deduced from the data, as is done according to a definite order in Arithmetic and Geometry. … Once people have learnt to do this in natural philosophy … they will perhaps be surprised that many things were unknown to them for so long––which should not be put down to the laziness of the true method, which alone sheds light. (pp. 133/135)
Here Leibniz reveals that he was aware of the significant progress of the new experimental philosophy as applied in disciplines, such as chemistry, anatomy and botany, and at the same time the lack of progress in using this for developing a philosophy of nature. He puts it down to the lack of a method that is analogous to that in mathematics. The same lack of progress had been noticed by other critics of the new experimental philosophy, particularly the English wits, but rather than viewing this as a methodological deficiency they simply mocked the new natural philosophers in works such as Thomas Shadwell’s play The Virtuoso which appeared in 1676, the very same year as Leibniz’s visit.
Charinus, who speaks next in the dialogue, uses Pacidius’ observations as a segue into a discussion of the nature of motion, and so the methodological reflections tail off at this point. However, the little we do have gives us a fascinating window onto Leibniz’s views of the state and prospects of the new experimental philosophy with its emphasis on natural history in the mid-1670s.
Cartesian Empiricisms – a Reply
Peter Anstey writes …
The forthcoming book Cartesian Empiricisms edited by Mihnea Dobre and Tammy Nyden promises to extend our knowledge of the experimental practices and philosophy of experiment amongst many of Descartes’ followers.
Dobre, however, claims that the book will offer more than a study of these writers. He says in his recent post that what we find in these neo-Cartesians ‘seems to escape the ESD’ (experimental–speculative distinction, my italics). In what sense might it be true that Cartesians doing experiments might escape the ESD? Is it that the ESD cannot explain them? Or, more strongly, is it that their experimental practices contradict the central tenets of the actors’ categories of experimental philosophy and speculative philosophy? And what is the value of persisting with the term ‘empiricism’ to describe the neo-Cartesians’ engagement with experiment?
In my view, the fact that some Cartesians performed experiments is of great interest, but it is also grist for our mill: it actually enriches the evidential base for the claims that we have made on this blog and in recent publications. For it shows that, like all other speculative systems, Cartesian natural philosophy was also subject to the court of experiment.
We have never claimed that proponents of speculative systems like Cartesianism were necessarily opposed to experimental verification of their theories. Nor have we ever claimed that all experimental philosophers were adamantly opposed to speculation: some were, but others, like Robert Boyle and Robert Hooke, were not.
We have claimed that the Cartesian vortex theory came to be regarded by many as the archetypal speculative theory in natural philosophy. Indeed, this was the virtually the standard view in England from the late 1690s when the term ‘our vortex’ starts to disappear and Newton’s arguments against the Cartesian system began to be widely appreciated. But none of this implies that our claims about the ESD need somehow to be modified. In fact, there is evidence that distaste for speculative system building and a belief in the need for the construction of Baconian natural histories were constituents of the general methodological background to mid-seventeenth-century Parisian natural philosophy. The first article of the constitution of the Montmor academy, which met in Paris from the mid-1650s to around the time of the formation of the Académie des Sciences, says:
The purpose of the company shall not be the vain exercise of the mind on useless subtleties (subtiltés inutiles), but the company shall set before itself always the clearer knowledge of the works of God, and the improvement of the conveniences of life, in the Arts and Sciences which seek to establish them.
The anti-speculative element here is hard to miss. (Interestingly, none of the articles mention experiment.) Furthermore, it is well known that Christiaan Huygens recommended to Colbert that the newly formed Adadémie construct natural histories after the manner of Verulam.
Henry Testelin: Etablissement de l'Academie des sciences et fondation de l'observatoire (1666)
What I am hoping to glean from Cartesian Empiricisms is an answer to the following question:
Did the Cartesians practise a form of experimental philosophy analogous to that of the Fellows of the early Royal Society?
This question is important for a number of reasons. The work of Trevor McClaughlin on Rohault, for example, has shown that early Cartesians carried out experiments. Yet we still lack a detailed assessment of the nature, theory and practice of experiments amongst the neo-Cartesians in the three decades after Descartes’ death. There is no doubt that they performed experiments for illustrative purposes and repeated many classic experiments for pedagogical purposes. But did they engage in experimental programs with a view to acquiring new knowledge of nature and to modifying and developing natural philosophical knowledge?
What makes this issue particularly pressing is that there is evidence from the late 1650s and early 1660s that the natural philosophers who met in the Parisian academies, such as the Montmor academy which included several prominent Cartesians, performed experiments, but were not really practising experimental natural philosophy. Henry Oldenburg reported to Michaelis in April 1659 that the philosophical academies in Paris: ‘are rich in promises, few in performance’ (Corresp. of Oldenburg, 1: 241). Three months later Oldenburg wrote to Boyle from Paris saying:
we have severall meetings here of philosophers and statists which I carry your nevew to, for to study men as well as books; though the French naturalists are more discursive, than active or experimentall. (Corresp. of Oldenburg, 1: 287)
My hope, therefore, is that Cartesian Empiricisms will answer this very pressing question.
