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Author Archives: Peter Anstey

A response to Anstey’s ‘Experimental Philosophy before the Restoration’

A guest post by Mordechai Feingold.

Mordechai Feingold writes …

I thank Peter Anstey for drawing attention to my ‘“Experimental Philosophy”: Invention and Rebirth of a Seventeenth-Century Concept’, and for giving me the opportunity to correct certain misunderstandings of my argument.

Anstey begins: ‘Feingold has done us a real service by trawling through the Hartlib Papers and uncovering every use of the term “experimental philosophy” in them.’ The unsuspecting reader of the blog may conclude that the paper is devoted in its entirety to such minute study; in fact, only a third is given over to the Hartlib papers. More serious, however, is Anstey’s insinuation that on the basis of such a survey I conclude: ‘there was no such thing as experimental philosophy before 1660’. I make no such claim. As both the title and the content of my article make abundantly clear, I argue explicitly that it was the concept of ‘experimental philosophy’, not the practices that would be identified later under such term, that was absent before the Restoration.

Anstey pivots to my claim that when John Aubrey, John Wallis, and Anthony Wood described, two decades and more after the events, the activities carried out at Oxford during the 1650s, they anachronistically projected the term ‘experimental philosophy’ onto such activities—thereby leading historians to assume that the term had been in use already back then. Anstey disagrees. ‘As early as 1659 in his Seraphic Love’, he writes, ‘Boyle had been described by the anonymous author … of the Advertisement to the ‘Philosophicall Readers’ as a lover of ‘Experimentall Philosophy’. I was aware of this reference. However, since the first edition of Seraphic Love was published in late September 1659, and since it is not at all clear whether the anonymous second advertisement was actually included in the initial printing of the book, I considered the following statement sufficient to denote Boyle’s centrality to the revamping of the concept: ‘By early 1660 Boyle added “experimental philosophy” to his rhetorical repertoire, thereby becoming intimately involved in refitting the meaning of the phrase’. I documented the statement by citing the very expressions from New Experiments Physico-Mechanical, Touching the Air that Anstey cites against my interpretation. In particular, Anstey claims, the context in which Boyle referred to John Wilkins as the ‘Great and Learned Promoter of Experimental Philosophy’ is ‘entirely experimental’—thereby implying that I denied the existence of experimental activity before 1660. Anstey further contends that ‘Boyle could hardly have been anachronistic here, for this was written before 1660 about the very recent past, and yet his comments square almost exactly with those of Wallis, Aubrey and Wood’. I don’t see the problem here. The reference to Wilkins was obviously added to the discussion of the twentieth experiment when Boyle prepared the manuscript for press in early 1660. Thus, the inclusion of the term coheres perfectly with the other references to ‘experimental philosophy’ in the book.

Ultimately, whether Boyle started using the term in late 1659 or in early 1660 is of no great matter. What is important, and this is the point I insist on, is that Boyle and other members of the Royal Society—with the notable exception of William Petty whom I discuss at some length in my article—had previously used terms other than ‘experimental philosophy’ to describe their scientific activities. And in view of my pronounced aim to probe the changing fortunes of a concept, I’m puzzled by Anstey’s characterization of my undertaking as a denial of the historical relations furnished by Aubrey, Wallis, Wood, and Boyle concerning the existence of a flourishing experimental activity at Oxford during the 1650s. My intent was to show why it was only around 1660 that Boyle and his Royal Society colleagues decide to appropriate the term ‘experimental philosophy’ to describe their activities, thereby imbuing it with a fixed conceptual and polemical meaning. Given Anstey’s divergent understanding of the meaning and fortunes of ‘experimental philosophy’, it is understandable why he is reluctant to accept my argument or my periodization. This divergence notwithstanding, however, ultimately Anstey and I share much more in common than we disagree.

Experimental Philosophy before the Restoration

In a recent article, Mordechai Feingold has done us a real service by trawling through the Hartlib Papers and uncovering every use of the term ‘experimental philosophy’ in them. His conclusion after surveying them all is that the term was used without a common determinate referent. This raises the question: Did experimental philosophy exist in England before the Restoration of the monarchy in 1660? Feingold argues that there was no such thing as experimental philosophy before 1660 and that those in later years who claimed that there was were being anachronistic: they were projecting the experimental philosophy of the 1660s or even the 1670s back into the late 1650s.

What evidence does he adduce for his claim of anachronism? First, there is the comment by John Aubrey from the 1680s which describes John Wilkins in the 1650s as ‘the principal reviver of experimental philosophy … at Oxford, where he had weekly an experimentall philosophy clubbe …’. Second, there are the comments of Anthony Wood from later years, such as his description of Lawrence Rooke moving to Oxford because he was ‘much addicted to experimental philosophy’. Third, there is John Wallis’ defense of himself in 1678 against the charges of William Holder. Like Aubrey, Wallis refers to the meetings at Oxford in the 1650s. Wallis is concerned to correct Holder’s own recollection of events in 1659 and so is almost certainly trying to recollect accurately. He claims, correcting Holder:

the Set Meetings for such a purpose (which had before been there [i.e. at Wadham College]) were then dis-used, and had been for a good while. And, what was of this nature at Oxford (about Experimental Philosophy) in those days, was rather at Mr. Boyl’s Lodgings, than at Wadham-Colledge. (Wallis, Defence of the Royal Society, London, 1678, p. 5)

So we have (1) Aubrey in the 1680s mentioning an experimental philosophy club and describing Wilkins as the ‘principal reviver of experimental philosophy’; (2) Wood many years after the event describing Rooke as moving to Oxford because he was addicted to experimental philosophy; (3) Wallis in 1678 describing the Oxford meetings as being held at Boyle’s lodgings and being ‘about Experimental Philosophy’. Taken at face value, these might all be backward projections onto the meetings of the late 1650s in Boyle’s lodgings.

However, when these comments are juxtaposed with a contemporaneous account they look quite different. As early as 1659 in his Seraphic Love Boyle had been described by the anonymous author (perhaps Boyle himself) of the Advertisement to the ‘Philosophicall Readers’ as a lover of ‘Experimentall Philosophy’ (Boyle, Works, 1: 60). But the most interesting uses of the term appear in his Spring of the Air. The experiments in Boyle’s Spring of the Air were begun in 1657 and the work was completed by 20 December 1659. He tells us as much in the work itself. Negotiations with the printer were well underway as early as 26 January 1660 (Robert Sharrock to Boyle, 26 Jan 1660, Boyle, Correspondence, 1: 399). In Spring of the Air Boyle uses the term ‘experimental philosophy’ three times. For example, he speaks of ‘my grand Design of promoting Experimental and Useful Philosophy’ and he makes the following comment in passing when discussing Experiment 20 on the question as to whether, like the air, water has a kind of spring:

And, on this occasion, it will not perhaps be amiss to acquaint Your Lordship here (though we have already mention’d it in another Paper, to another purpose) with another Expedient that we made use of two or three years ago, to try whether or no Water had a Spring in it. About that time then, That Great and Learned Promoter of Experimental Philosophy Dr. Wilkins, doing me the Honor to come himself, and bring some of his inquisitive Friends to my Lodging … (Boyle, Works, 1: 207)

The context of the recollection from c. 1657 is entirely experimental. Note the reference to Wilkins as ‘That Great and Learned Promoter of Experimental Philosophy’. This is similar to Aubrey’s claim that Wilkins was the ‘principal reviver of experimental philosophy’. Note too the claim that the meeting was in Boyle’s lodging, the same location, indeed the same term as used by Wallis. Boyle could hardly have been anachronistic here, for this was written before 1660 about the very recent past, and yet his comments square almost exactly with those of Wallis, Aubrey and Wood.

Where does this leave Feingold’s case for anachronism? In my view Boyle’s contemporaneous comments provide persuasive corroborating evidence that the claims of Wallis, Aubrey and Wood are accurate recollections of the pre-Restoration Oxford meetings. That is, Boyle’s comments should be used to shed light on what Aubrey, Wallis and Wood meant by the term in the decades following the Oxford meetings rather than the other way around. According to Boyle in 1659, those meetings were in his lodgings and concerned experimental philosophy, just as the others later claimed. The case for the anachronistic reading is, therefore, seriously weakened in the light of Boyle’s testimony. It seems far more likely that there was an activity carried out by a small group in the late 1650s in Boyle’s Oxford rooms that was and still is aptly described as experimental philosophy.

Experimental Philosophy and Early Modern Ethics: Turnbull and Fordyce

Alberto Vanzo writes …

Experimental philosophy is often portrayed as an exciting or controversial new development in philosophy. Yet, some have claimed that the practice of experimental philosophy is traditional and that it ‘began to flourish’ in the early modern period. Is it true that the practices and methods of current-day experimental philosophy is a traditional philosophical practice?

To shed light on this question, I will focus on George Turnbull, David Fordyce and (in my next post) David Hume. As Juan has shown (e.g. here and here), these authors stressed that their ethics derives from ‘plain uncontroverted Experiments’ and ‘reasoning from experiment’. Do Turnbull and Fordyce ethics adopt the practices and methods of current-day experimental philosophers?

Two practices are especially relevant to this question:

  • Experimental philosophers object to the practice of developing philosophical arguments on the basis of intuitions, without assessing how widely those intuitions are shared and whether they are influenced by factors such as ethnic background, gender, or philosophical training. Accordingly, experimental philosophers engage in systematic investigations of people’s intuitions.
  • More broadly, experimental philosophy can be characterised as the practice of systematically relying on empirical evidence in attempting to answer philosophical questions.

There are two reasons to think that Turnbull’s and Fordyce’s ethics is not an early instance of experimental philosophy.

1. The buck-passing strategy

Much of Turnbull’s and Fordyce’s ethics depends on their account of people’s feelings and behaviour. For instance, Fordyce outlines the passions that people experience at various stages of their lives: infants’ affection for their parents, children’s ‘Love of Action, of Imitation’, and so on. In support of his portrayal of human passions, Fordyce writes:

Whether this historic Draught of Man … be just or not, is a Matter, not so much of Reasoning, as common Sense and common Experience. Therefore let every one consult his Experience of what he feels within, and his Knowledge of what is transacted abroad, in the … World in which he lives; and by that Experience, and that Knowledge, let the Picture be acknowledged Just, or pronounced the Contrary.

Here and elsewhere, instead of detailing their observations, Turnbull and Fordyce appeal to a generic ‘common experience’ and pass the buck to their readers, inviting them to consult their own experience. This may be construed as a merely rhetorical move, or as an appeal to their readers’ intuitions. Either way, it is a far cry from experimental philosophers’ systematic provision of actual, specific experiences in support of their claims.

2. Thought Experiments

Turnbull and Fordyce often rely on intuitions elicited by thought experiments. They invite their readers to imagine a scenario and ponder a question, to elicit a judgement that is used as evidence for a philosophical claim. For instance, Turnbull asks his readers to imagine that someone paid them to have a sentiment of approbation for an instance of ‘villany’ or ‘treachery’. Would this bribery be successful? Turnbull expects his readers to answer that it wouldn’t, because they cannot bring themselves to have sentiments of approbation for such actions.

This is the procedure that armchair philosophers adopt when they appeal to intuitions in support of their claims. Like armchair philosophers, Turnbull and Fordyce take it for granted that, by reflecting on given cases, readers will elicit the very same judgements that their own reflection has elicited. They assume that people’s moral intuitions are uniform. They never suggest that an empirical inquiry might be necessary to confirm this assumption. In fact, Turnbull and Fordyce display little interest for cross-cultural moral divergences.

In sum, Turnbull’s and Fordyce’s appeals to a generic common experience and their armchair reliance on intuitions make them unlikely predecessors of current-day experimental philosophers. In my next post I will turn to Hume. Which other early modern moral philosophers should I focus on to establish if experimental philosophy is a traditional philosophical practice? I would appreciate your suggestions in the comments or via email.

Voltaire: Experimental Philosopher

Voltaire, détail du visage (château de Ferney)

Voltaire, détail du visage (château de Ferney)

Peter Anstey writes …

The French Philosophe Voltaire played an important role in the transmission of experimental natural philosophy to France in the 1730s. That Voltaire regarded the emergence of experimental philosophy as a pivotal moment in history is seen in his history of The Age of Louis XIV (1751). In the Introduction to this work he speaks of the Italians of the Renaissance being ‘in possession of everything that was beautiful, excepting music, which was then in but a rude state, and experimental philosophy, which was everywhere unknown’.

The decisive moment came in the early seventeenth century in the writings of Francis Bacon. For, in his Letters Concerning the English Nation (Oxford, 1994) that appeared in English and French in 1734, Voltaire credits Bacon with being the first experimental philosopher:

He is the Father of experimental philosophy … no one, before the Lord Bacon, was acquainted with experimental Philosophy, nor with the several physical Experiments which have been made since his Time. (pp. 51–2)

But did Voltaire himself take up experimental philosophy or was he merely a herald and conduit for this movement to the French reading public?

Two works suggest that Voltaire fully embraced the new experimental philosophy that he had encountered in England in the 1720s. The first is his Treatise on Metaphysics that he wrote in 1734, the year in which his Letters appeared but which was published posthumously. This work bears the marks of someone who had imbibed the methodological position of the new experimental philosophy both in its rejection of speculative philosophy and hypotheses and the priority it gives to observation and experiment. For example, he says:

It is clear that one should not make hypotheses. We ought not to say ‘Let us begin by inventing some principles with which we will try to explain everything’, but we ought to say, ‘Make an exact analysis of things and then we will try with great diffidence whether they are related to certain principles’.

He goes on to claim ‘when we can help ourselves with neither the compass of mathematics, nor the torch of experiment and natural philosophy, it is certain that we are not able to do anything’ (ibid., p. 301).

The second work is his ‘Essay on the nature of fire and its propagation’, an essay he submitted for the Académie des sciences prize in 1738. As things turned out Leonhard Euler’s essay won the prize, but Voltaire’s submission and that of Madame du Châtelet were published alongside Euler’s winning essay in the Recueil des pieces qui ont remporté le prix de l’Académie royale des sciences in 1739. This is Voltaire’s only serious foray into experimental natural philosophy.

In the Part One of the essay, the part that addresses the nature of heat, he uses the experiments of others to argue for an Aristotelian theory of heat as an element. In doing so he cites the experimental work of Boyle, Newton and Boerhaave. However, in the second article of Part Two of the essay, on the subject of how fire acts on other bodies, Voltaire relates a whole series of experiments that he had performed himself. This is with a view to establishing certain laws by which fire acts, the second of which purported laws is an inverse square law analogous to Newton’s law of gravitational attraction! (p. 201) At one point he tells us:

the comparative degrees of heat of fluids of minerals and of vegetables can, I believe, be known with the aid of a single thermometer constructed on the principles of Mr de Réaumur.

There is only one precaution to take, and this is that the spirit of wine should not boil in the thermometer. To achieve this I plunged only up to half of the ball of the thermometer in the boiling liquors. (p. 207)

Much more could be said about this fascinating essay, but the key point of interest here is that it is a demonstration of Voltaire’s commitment to and practice of experimental natural philosophy.

He may never have experimented again, yet he continued to refer to experimental philosophy, alluding to his essay on heat in his Metaphysics of Newton (La métaphysique de Neuton, Amsterdam, 1740, p. 49) and, most famously, referring to experimental philosophy in his literary works, including Candide (1759) and Micromégas (1752).


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.

The ESD and the Berlin Académie

Peter Anstey writes …

One good indicator of the wide dissemination of experimental philosophy in the early modern period is the extent to which it manifested itself in the institutions of the time.

The first chair in experimental philosophy was the Plumian Chair in Experimental Philosophy and Astronomy that was established at the University of Cambridge in 1707. The first incumbent of the Chair was Roger Cotes who went on to edit the second edition of Newton’s Principia. We have also mentioned Abbé Nollet before on this blog and the fact that he was appointed Professor Royale de physique expérimentale at the Collège de Navarre in Paris in 1753.

It is of great interest, therefore, to note that the important restructuring of the Académie Royale des Sciences at Belles Lettres in Berlin in the 1740s also reflected the central place that was now accorded to experimental philosophy in Europe.


Pierre Louis Moreau de Maupertuis (Public Domain)

King Frederick II of Prussia sought to reinvigorate the institution by appointing the prominent French savant Pierre-Louis Moreau de Maupertuis as President of the Académie in 1746 and restructuring it into four classes. In the ‘Rules of the Academy’ from 1746, which are the official position of the Académie, the nature of these four classes is spelt out as follows:

The Academy will continue as it is, divided into four classes

  1. The class of Experimental Philosophy, including chemistry, anatomy, botany and all sciences that are founded on experiment.
  2. The class of Mathematics, including geometry, algebra, mechanics, astronomy and all the sciences which have as their object the abstract and numbers
  3. The class of Speculative Philosophy which will apply to logic, metaphysics and morals
  4. The class of literature will include antiquities, history and languages.

(Histoire de l’Académie Royale des Sciences et Belles Lettres, 1748, pp. 3–4)

There are a number of striking features of these classes. First, note that Experimental Philosophy is here grouped with Speculative Philosophy. It is clear that a form of experimental-speculative distinction is part and parcel of the Academicians’ conception of natural philosophy.

Second note that anatomy and botany are included in Experimental Philosophy. This is striking because it is closer to the manner in which experimental philosophy in Britain in the seventeenth century was understood in so far as it encompasses disciplines that were often regarded as part of natural history. In the mid-eighteenth century in France, by contrast, Nollet regarded physique expérimentale and natural history as distinct disciplines.

We note also that astronomy and mechanics, two sciences in which Maupertuis excelled, are grouped under Mathematics. This is in spite of the fact that they required observation and experiment. Indeed, Maupertuis’s fame rested in large part on his Lapland expedition of 1736 on which he was able to establish experimentally that the Earth is an oblate spheroid. Yet this had implications for both mechanics and astronomy.

Furthermore, it is worth highlighting that morals is considered to be a speculative science. This provides an interesting contrast to the situation in mid-eighteenth-century Scotland where there was a concerted attempt, as David Hume put it ‘to introduce the experimental method of reasoning into moral subjects’.

We can obtain a clearer sense of just what each class encompassed by examining the Histoire de l’Académie two years later. Here is how experimental philosophy is described:

Experimental Philosophy includes all natural history, all knowledge for which one has need of eyes, of hands, and of all the senses. It considers the bodies of the universe covered with all their sensible properties. It compares these properties linking them together and deducing one from another. This science is all founded on experiment. Without it reason is always in danger of falsehoods and losing itself in systems that it denies. However, experiment also has need of reason; it saves the natural philosopher time and pains; it makes him grasp all at once certain relations that deliver him of several useless operations; and it permits him to turn all his focus towards those phenomena that are decisive. (Histoire de l’Académie, 1750, p. 118)

By contrast speculative philosophy is that which ‘considers those objects that don’t have any properties of bodies. The supreme being, the human mind, and all that which belongs to the mind is the object of this science. The nature of bodies themselves, as represented by our perceptions, even if they are things other than these perceptions, they are in its remit’ (Histoire de l’Académie, 1750, p. 120).

Interestingly, speculative philosophy here is not a method that begins with hypotheses and principles and constructs natural philosophical systems. Rather it includes subject matter that is beyond the scope of natural philosophy, what we would call metaphysics. Of course, metaphysics had long been associated with speculative philosophy. Newton’s railing against metaphysics is a case in point. However, for Newton the hypothetical or speculative philosophers allowed metaphysics to intrude into their natural philosophical reasoning. Here, by contrast, speculative philosophy is clearly demarcated from the study of material bodies.

Is this indicative of a shift towards regarding speculative philosophy as pertaining to metaphysics rather than to natural philosophy in mid-eighteenth-century Europe? I would be keen to know of parallel definitions of speculative philosophy.



Experimental Philosophy and Mechanical Philosophy II: The Case of Robert Boyle

Peter Anstey writes …

What is the precise relation between experimental philosophy and mechanical philosophy in the seventeenth century? In my last post I showed how neither Henry More nor Henry Stubbe were particularly clear about this. In this post I examine the view of Robert Boyle.

Boyle is sometimes credited with coining the English term ‘mechanical philosophy’* and he was certainly the first person to use the term ‘experimental philosophy’ in a book title. In 1663 he published Of the Usefulness of Experimental Philosophy which was soon followed by Henry Power’s Experimental Philosophy of 1664.

If we look at frequencies of use in Boyle’s writings, it turns out that he used the term ‘experimental philosophy’ roughly twice as often as ‘mechanical philosophy’ or ‘mechanical hypothesis’. This raw fact is in itself rather telling for those recent historiographical debates over the nature and status of mechanical philosophy in early modern philosophy that almost entirely ignore experimental philosophy. However, the key question is: Were the terms synonyms for Boyle or did they denote two different things?

The best early statement of Boyle’s view of the content of experimental philosophy is in the ‘Proemial Essay’ to Certain Physiological Essays first published in 1661. He starts with a criticism of previous natural philosophers such as Aristotle and Campanella:

they have too hastily, and either upon a few Observations, or at least without a competent number of Experiments, presum’d to establish Principles, and deliver Axioms. (Works of Robert Boyle, 1999–2000, 2: 13)

What experimental philosophers should do instead is:

set themselves diligently and industriously to make Experiments and collect Observations, without being over-forward to establish Principles and Axioms, believing it uneasie to erect such Theories as are capable to explicate all the Phaenomena of Nature, before they have been able to take notice of the tenth part of those Phaenomena that are to be explicated. (Works of Robert Boyle, 2: 14)

This clearly has to do with the role of observation and experiment in relation to theory in the acquisition of knowledge about nature. Now let’s see how Boyle defines the mechanical philosophy. In The Excellency and Grounds of the Mechanical Hypothesis (aka the mechanical or corpuscular philosophy) Boyle states the kernel of the view as follows:

the Universe being once fram’d by God, and the Laws of Motion being setled and all upheld by His incessant concourse and general Providence; the Phænomena of the World  thus constituted, are Physically produc’d by the Mechanical affections of the parts of Matter, and what they operate upon one another according to Mechanical Laws. (Boyle Works, 8: 104)

The mechanical affections referred to here are the shape, size, motion and texture of corporeal bodies.

Now this is really quite different from experimental philosophy. For, it is the sort of theory that one should arrive at as a result of practising experimental philosophy. This is why Boyle’s book The Origin of Forms and Qualities has a ‘speculative part’, which outlines the theoretical content of the mechanical philosophy, and a ‘historical (or experimental) part’, which provides experimental support for the speculative theory. Here is how he describes the relation between the two parts:

it was very much wish’d, that the Doctrines of the new Philosophy (as tis call’d) [i.e. mechanical philosophy] were back’d by particular Experiments; the want of which I have endeavour’d to supply, by annexing some, whose Nature and Novelty I am made believe will render them as well Acceptable as Instructive.

Thus, for Boyle, experimental philosophy and mechanical philosophy are entirely distinct: the former provides the evidential grounds of the latter. This is why, as Dmitri Levitin has shown, Boyle prefers Democritus to Epicurus. In Boyle’s view, the former based his atomism on experimental philosophy, the latter on speculative philosophy. (Levitin, ‘The experimentalist as humanist: Robert Boyle on the history of philosophy’, Annals of Science, 71, 2014, 149–82).

It may be that some philosophers and even natural philosophers conflated experimental philosophy with mechanical philosophy, but in Boyle’s mind they were distinct.


* Actually, the question turns out to be slightly more complicated than it looks because Henry More used the term ‘mechanical hypothesis’ in 1653 (An Antidote against Atheism, 44) and when Boyle first introduces the term in 1661 in Certain Physiological Essays, he uses ‘Mechanical Hypothesis or Philosophy’ (Boyle Works, 2: 87).


Experimental Philosophy and Mechanical Philosophy I: The Case of Henry More and Henry Stubbe

Peter Anstey writes …

The mechanical philosophy, at least since the work of Marie Boas Hall and E. J. Dijksterhuis, has played a prominent role in the historiography of early modern natural philosophy. By contrast, experimental philosophy has been largely absent. Take, for example, Richard Westfall’s The Construction of Modern Science (Wiley, 1971). It has a whole chapter dedicated to the mechanical philosophy whereas the term ‘experimental philosophy’ appears only once in the entire book –– on the penultimate page –– and this is in a quote from Newton’s ‘General Scholium’ in a discussion of Newton’s concept of force and the term’s presence is irrelevant to Westfall’s narrative. It is also rather telling that the term ‘experimental philosophy’ does not even appear in the 662 pages of Floris Cohen’s The Scientific Revolution: A Historiographical Inquiry (Chicago, 1994).

It is interesting to reflect, therefore, that the English terms ‘experimental philosophy’ and ‘mechanical philosophy’ came into common use around about the same time, in the late 1650s. Moreover, when the new experimental philosophy emerged in England in the 1660s it was frequently associated with and even conflated with the mechanical philosophy. (Experimental philosophy was also commonly identified with corpuscular philosophy, though this is not our concern here.) Robert Hooke famously spoke of ‘the real, the mechanical, the experimental Philosophy’ in the Preface to Micrographia of 1665. By the end of the seventeenth century, however, the two had come to be fairly clearly demarcated. The Newtonian John Keill, for instance, lists four ‘sects’ of his day, two of which are the experimental philosophers and the mechanical philosophers (Introductio ad verum physicam, Oxford, 1702, p. 2).

The process by which this ‘decoupling’ occurred is quite convoluted and this is the first in a series of posts that will attempt to set out some points of reference from which we can understand how experimental philosophy and mechanical philosophy came to be clearly demarcated.

Let us begin with two Henrys, Henry More and Henry Stubbe. More was not a practitioner of experimental philosophy: in fact, he was not a natural philosopher at all. He was, however, a Fellow of the Royal Society. Stubbe was a physician and critic of the Royal Society and experimental philosophy. Now when Henry Stubbe attacked the Royal Society, and in particular its apologist Joseph Glanvill, he claimed that Henry More had given up his association with the Society because of the Society’s commitment to the mechanical philosophy which tended to atheism (Stubbe, Legends no Histories, London, 1670, p. 173).

More responded to Stubbe’s claims in a letter to Glanvill (c. 1671):

he [Stubbe] looks upon that Mechanick Philosophy which I oppose, to be the Philosophy the Royal Society doth profess, or would support. But the Philosophy which they aim at, is a more perfect Philosophy, as yet to be raised out of faithful and skilful Experiments in Nature, which is so far from tending to Atheism, that I am confident, it will utterly rout it and the Mechanical Philosophy at once, in that sense which I oppose, namely, as it signifies a Philosophy that professeth, That Matter having such a Quantity of Motion as it has, would contribute it self into all those Phaenomena we see in Nature. (Glanvill, A Praefatory Answer to Mr Henry Stubbe, p. 155)

More opposes a mechanical philosophy that is competent to explain everything and leaves no place for a deity. But this does not mean that he opposes mechanical explanations tout court. Alluding to a passage that Stubbe quotes from Thomas Sprat’s History of the Royal-Society of London he says:

I believe indeed most of us, I am sure my self does conceive, that Generation, Corruption, Alteration and all the Vicissitudes of corporeal Nature are nothing else but Unions and Dissolutions … of little Bodies or Particles of differing Figures, Magnitudes, and Velocities. But this thus bounded is not the Mechanical Philosophy, but part of the old Pythagorick or Mosaick Philosophy … (p. 156)

More is happy to acquiesce in corpuscular explanations, so long as their limitations are recognised. He goes on:

I think it is plain, what Mechanical Philosophy that is, that may incline Men to Atheism, and that is not the experimental Philosophy, which the Royal Society professes. (p. 157)

Clearly More accepts both the corpuscular explanations of a mitigated form of mechanism and experimental philosophy. Just how he conceives the relation between the two, however, is not clear from this letter.

When we turn to Stubbe we find a similar lack of differentiation. For example, earlier in Legends no Histories, Stubbe claims that no prince has ever been called great because he used ‘any knick-knacks of Experimental or Mechanical Philosophy alone’ (p. 4).

What these passages show is that for some writers the relation between mechanical philosophy and experimental philosophy was not clearly defined. They also illustrate how tempting it would be for those scholars who view the emergence of modern science through the lens of mechanism to reduce experimental philosophy to mechanical philosophy.

It may even be that part of the explanation of the relative neglect of experimental philosophy in the historiography of early modern natural philosophy is the tendency to conflate it with mechanical philosophy. In my next post I shall examine Robert Boyle’s view of the relation between mechanical and experimental philosophy.


James Bradley’s Lectures on Experimental Philosophy

Peter Anstey writes …

In my last post I discussed the astronomer James Bradley who taught experimental philosophy in Oxford from 1729 until 1760. Since then I have examined Bradley’s extant lectures in the Bodleian Library, Oxford.

One of the most interesting features of the lectures is the manner in which the distinction between experimental and speculative philosophy is presented at the very beginning of his opening lecture. Bradley commences with a general reference to the laws of nature:

/1/ … these are no otherwise to be discovered than by experiments & observation & examining the Phaenomena & finding from them by what /2/ laws their motions are ordered & regulated. which is properly the Business & scope of Natural & Experimental Philosophy. (Bodleian Library MS Bradley 1, p. 1 (Used with permission of Bodleian Libraries, University of Oxford)

This view of natural philosophy is interesting in so far as it places laws of nature and experiment to the fore in a manner that was not possible before the advent of Newton’s Principia. Bradley continues:

But then our principal endeavour must be to learn the true & real manner in which the operations of Natur are actually performd & not content ours[elves] with framing Hypoth[eses] to explain how such Phaenom[ena] may be perform’d tis on this account that Reasoning much from Hypotheses in Natural Phil[osophy] is apt to lead people into mistakes and there is no likelier a method to avoid error than having recourse to experiments & trials (Bodleian Library MS Bradley 1, p. 2 (Used with permission of Bodleian Libraries, University of Oxford)

Note here the rhetoric of experimental philosophy: the warning against ‘framing Hypotheses’ which can lead to error, and the emphasis on experiment and observation. Bradley then expresses a form of fallibilism in his claims about the epistemic status of knowledge acquired by the method of ‘experiments & trials’:

/3/ Tho this is no doubt the most likely method of coming at the truth yet even in this manner of proceeding we must not expect to meet with Proof in Natural Philosophy so absolutely convincing as in pure mathematics because the Ideas we have to do with in Mathematics are the Productions of the mind itself & therefore we may have a more full adequate knowledge of them than of those we have in natural Philosophy which being fram’d from things without us they may not be just & consequently our deductions & reasonings about these may be liable to some uncertainty & leave some scruple upon the mind. (Bodleian Library MS Bradley 1, p. 3 (Used with permission of Bodleian Libraries, University of Oxford)

Bradley is honest in his claim that one should not expect mathematical certainty in matters of experimental natural philosophy. Yet he also believes that there are measures that one can take to assure us that our inferences from experiments are secure:

In order to remove all scruple as much as possible & that the mind may assent to the conclusions drawn from facts & experiments in searching into the operations of nature Sir I. Newton lays down the following Rules of Arguing in Natural Philosophy. (Bodleian Library MS Bradley 1, p. 3 (Used with permission of Bodleian Libraries, University of Oxford)

He then summarises the four rules of philosophising that Newton first published in the second edition of the Prinicpia.

What Bradley is providing in his very first lecture is a methodological statement that reveals his conception of natural philosophy and the means by which one acquires the knowledge of nature. This is what generations of students were taught at Oxford when they enlisted in his courses in the Old Ashmolean Museum. Now there are some scholars who question the value of the experimental/speculative distinction as terms of reference for understanding early modern British natural philosophy. It is necessary, however, to ask what more it would take for the ESD to be taken seriously than a lecture on natural philosophy that was repeated at least 79 times over twenty-one years to inquisitive university students at Oxford University who were paying to be taught experimental philosophy by an eminent practitioner. This is not empty ‘method talk’, this is not the RED, the rationalism/empiricism distinction, in disguise. These are the actors’ terms of reference, and they are not in polemical writings, or in promotional puffs prefacing controversial works in natural philosophy, but in ordinary undergraduate lectures.

Teaching Experimental Philosophy V: the case of James Bradley

Peter Anstey writes …

James Bradley (c. 1692–1762) was one of the leading English astronomers of the eighteenth century, being appointed to the Savilian Chair in Astronomy at Oxford in 1721 on the death of John Keill, before being appointed as Astronomer Royal in 1742 on the death of Edmund Halley. He announced his discovery of the phenomenon of nutation in the movement of the Earth in 1748 and was subsequently awarded the Royal Society’s Copley Medal.

Our interest in Bradley, however, lies in his teaching of experimental philosophy at Oxford for over thirty years. We have already discussed on this blog the roles of John Keill and Jean Theophilus Desaguliers in the teaching of experimental philosophy at Oxford (and in the case of Desaguliers in London). Keill began teaching around 1700 and was succeeded by Desaguliers in 1713. After a hiatus of three or four years it seems that John Whiteside of Christ Church began to lecture on experimental philosophy (his lectures survive in Cambridge University Library) and he was replaced in 1729 by Bradley. Bradley gave a staggering 79 (at least) courses on experimental philosophy from 1729 to 1760. Thus, apart from a short break experimental philosophy was constantly taught in Oxford University for the first six decades of the eighteenth century. This was in spite of the fact that, unlike Cambridge University, there was no Chair in experimental philosophy.

Interestingly, a register of all those who attended Bradley’s lectures from April 1746 to April 1760 survives. It is reproduced as Appendix E of volume XI of Gunter’s Early Science in Oxford (Oxford, 1937) and shows the name and college affiliation of every student who attended the lectures. Each course averaged 57 students. The lectures were given in the Old Ashmolean Museum, which today is the History of Science Museum. Happily some of Bradley’s lecture notes survive in the Bodleian Library.

Since there was no Chair in experimental philosophy at Oxford, Bradley had to secure some source of income for his lectures. We know that for his last 33 courses he charged two guineas for the first lecture and one gineau for the second lecture. It must have been a handy little earner. According to the Memoirs of Bradley, thirty-one pounds had been set aside each year for a reader in experimental philosophy by convocation in 1731 from the estate of the late Bishop of Durham, Nathaniel Crewe, but Bradley didn’t see any of this money until 1749.

Bradley’s lectures were similar in content to those of Desaguliers and of Roger Cotes and William Whiston in Cambridge. The syllabus remained fairly static for sixty years. It included the laws of nature, mechanics, hydrostatics and optics. What this shows us is that the term ‘experimental philosophy’ didn’t only refer to a method of acquiring knowledge of nature, but also to the actual knowledge acquired through the application of this method. This may not seem a particularly deep historical insight, but it does reflect the success of experimental philosophy of the seventeenth century. The teaching of natural philosophy had come a very long way from its emergence in the 1660s to the time that an average of over 50 undergraduates were signing up for courses in it from 1746!