Are Newton’s Laws Experimentally Confirmed?
Kirsten Walsh writes…
Previously on this blog, I have argued that the combination of mathematics, experiment and certainty are an enduring feature of Newton’s methodology. I have also highlighted the epistemic tension between experiment and mathematical certainty found in Newton’s work. Today I shall examine this in relation to Newton’s ‘axioms or laws of motion’.
In the scholium to the laws, Newton argues that his laws of motion are certainly true. In support, however, he cites a handful of experiments and the agreement of other mathematicians: surprisingly weak justification for such strong claims! In this post, I show how Newton’s appeals to experiment justify the axioms’ inclusion in his system, but not with the certainty he claims.
Newton begins:
- “The principles I have set forth are accepted by mathematicians and confirmed by experiments of many kinds.”
Newton expands on this claim, discussing firstly, Galileo’s work on the descent of heavy bodies and the motion of projectiles, and secondly, the work conducted by Wren, Wallis and Huygens on the rules of collision and reflection of bodies. He argues that:
- The laws and their corollaries have been accepted by mathematicians such as Galileo, Wren, Wallis and Huygens (the latter three were “easily the foremost geometers of the previous generation”);
- The laws and their corollaries have been invoked to establish several theories involving the motions of bodies; and
- The theories established in (2) have been confirmed by the experiments of Galileo and Wren (which, in turn confirms the truth of the laws).
These claims show us that Newton regards his laws as well-established empirical propositions. However, Newton recognises that the experiments alone are not sufficient to establish the truth of the laws. After all, the theories apply exactly only in ideal situations, i.e. situations involving perfectly hard bodies in a vacuum. So Newton describes supplementary experiments that demonstrate that, once we control for air resistance and degree of elasticity, the rules for collisions hold. He concludes:
- “And in this manner the third law of motion – insofar as it relates to impacts and reflections – is proved by this theory [i.e. the rules of collisions], which plainly agrees with experiments.”
This passage suggests that the rules of collisions support a limited version of law 3, “to any action there is always an opposite and equal reaction”, and that the rules themselves appear to hold under experimental conditions. However, this doesn’t show that law 3 is universal: which Newton needs to establish universal gravitation. This argument is made by showing how the principle may be extended to other cases.
Firstly, Newton extends law 3 to cases of attraction. He considers a thought experiment in which two bodies attract one another to different degrees. Newton argues that if law 3 does not hold between these bodies the system will constantly accelerate without any external cause, in violation of law 1, which is a statement of the principle of inertia. Therefore, law 3 must hold. As the principle of inertia was already accepted, this supports the application of law 3 to attraction.
Newton then demonstrates law 3’s application to various machines. For example, he argues that two bodies suspended from opposite ends of a balance have equal downward force if their respective weights are inversely proportional to the distances between the axis of the balance and the points at which they are suspended. And he argues that a body, suspended on a pulley, is held in place by a downward force which is equal to the downward force exerted by the body. Newton explains that:
- “By these examples I wished only to show the wide range and the certainty of the third law of motion.”
What these examples in fact show is the explanatory power of the laws of motion – particularly law 3 – in natural philosophy. Starting with collision, which everyone accepts, Newton expands on his cases to show how law 3 explains many different physical situations. Why wouldn’t a magnet and an iron floating side-by-side float off together at an increasing speed? Because, by law 3, as the magnet attracts the iron, so the iron attracts the magnet, causing them to press against one another. Why do weights on a balance sometimes achieve equilibrium? Because, by law 3, the downward force at one end of the balance is equal to the upward force at the other end of the balance. These examples demonstrate law 3’s explanatory breadth. But these examples do not give us a compelling reason to think that law 3 should be extended to gravitational attraction (which seems to require some kind of action, or attraction, at a distance).
Newton, clearly, is convinced of the strength of his laws of motion. But this informal, discussion of the experiments he appeals to shows that he ought not be so convinced. As I see it, Newton has two projects in relation to his laws:
1) The specification of the laws as the axioms of a mathematical system; and
2) The justification of laws as first principles in natural philosophy.
I suggest that the experiments discussed give strong support for the laws in limited cases. This justifies their application in Newton’s mathematical model, but it does not justify Newton’s claims to certainty. In modern Bayesian terms, we might say that Newton’s laws have high subjective priors. In my next post, I shall sketch an account in which Newton’s laws gain epistemic status by virtue of their relationship to the propositions they entail.
Joseph Priestley on experimental philosophy and empiricism
![Joseph Priestley Rembrandt Peale [Public domain], via Wikimedia Commons](https://blogs.otago.ac.nz/emxphi/files/2014/04/256px-PriestleyPeale.jpg)
Joseph Priestley
Rembrandt Peale [Public domain], via Wikimedia Commons
Joseph Priestley is one of the most celebrated chemists of all time because of his role in the discovery of oxygen. So highly was he regarded that in 1922 the American Chemical Society named their most prestigious medal ‘The Priestley Medal’.
Priestley was born in 1733 and died in 1804. Thus, he flourished in the latter decades of the era of early modern experimental philosophy and a survey of his writings reveals that he embraced experimental philosophy. Indeed, by the late eighteenth century the experimental approach to natural philosophy was virtually without a rival in Britain. When analysing his writings on natural philosophy there is no sense that he believed that experimental philosophy needed to be defended or justified at all. To be sure, one finds the usual rhetoric of experimental philosophy, such as his comment in his Experiments and Observations relating to various Branches of Natural Philosophy (London, 1779) that:
Speculation without experiment has always been the bane of true philosophy. (Preface, vii)
Yet when one turns to his Heads of Lectures on a Course of Experimental Philosophy (London, 1794) the term ‘Experimental Philosophy’ in the title is entirely unselfconscious. He opens Lecture I with a statement of the aim of the discipline:
The object of experimental philosophy is the knowledge of nature in general, or more strictly, that of the properties of natural substances, and of the changes of those properties in different circumstances. This knowledge can only be attained by experiment, or observation. (p. 1)
He goes on to mention one of the ‘rules of philosophizing’ in this discipline: ‘to admit no more causes than are necessary to account for the effects’ (p. 3). Of course, this is Newton’s first rule of philosophizing from the second edition of the Principia and it is hardly surprising that Priestley goes on to claim that given the ‘power of gravity’ ‘we are authorized to reject the Cartesian Vortices’ (ibid.).
One might, therefore, regard Priestley’s writings as not having anything to teach us about early modern experimental philosophy. And yet there is at least one point that is worth highlighting, for, Priestley was the second person to use the term ‘empiricism’ in the title of a book in English. The first was Francis Guybon in his An Essay concerning the Growth of Empiricism; or the Encouragement of Quacks, London, 1712 which was an attack on medical quacks.
Then in 1775 Priestley published a book entitled Philosophical Empiricism: containing Remarks on a Charge of Plagiarism respecting Dr H––. He had been attacked by the Irish physician Bryan Higgins who had accused him of plagiarism and Priestley defended himself, attacking many claims in Higgins’ lectures and concluding:
These and suchlike long-exploded, and crude notions (so many of which I believe were never thrown together into the same compass since the age of Aristotle or Cartesius) are delivered in a manner and phrase so quaint, and a tone so solemn and authoritative, as gives me an idea that I cannot express otherwise than by the term Philosophical Empiricism. (p. 59)
What is interesting here is that ‘empiricism’ is used as a pejorative and is loosely associated with Descartes! This all predates the Kantian Rationalism and Empiricism distinction –– the RED. It is even tempting to claim that it shows the inappropriateness of foisting the term ‘empiricism’ in its Kantian sense on eighteenth century thinkers when it already had strong currency in eighteenth-century English with an entirely different meaning.
Testimony and evidence from the scriptures
Juan Gomez writes…
For those familiar with the rhetoric and methodology of Early Modern Experimental Philosophy (the faithful readers of this blog among them) it is no surprise that the emphasis on facts, observation, and experiment as the only solid grounds of knowledge was highlighted in almost every published text by the promoters of the experimental method. Within natural philosophy, the relevant facts and experiments were confined to nature and its workings. However, pinpointing the relevant facts and observations for knowledge in areas outside of natural philosophy was a more delicate matter. As we have argued for in this blog, the methodology of Early Modern Experimental Philosophy was adopted by many eighteenth-century figures in areas traditionally contained under moral philosophy, such as ethics, aesthetics, and theology. But which sort of facts and observations entitled them to apply the same methodology that had contributed so much to the progress of mankind and our knowledge of the natural world?
George Turnbull (the philosopher, teacher, and theologian who has many times been the subject of our posts) thought that introspection could give us access to facts about the anatomy of our mind, and that paintings provided in moral philosophy the same role experiments did in natural. But what about facts and observations regarding religious thought? A couple of years ago I commented on Turnbull’s ‘experimental theism.’ We saw how Turnbull argued that the miracles performed by Jesus Christ serve as the samples and experiments that prove that he truly was the son of God and possessed knowledge of a more perfect stage in nature. However, the only evidence we have of those miracles is found in the gospels of the apostles, so why is it that those accounts of miracles count as proper evidence? David Hume’s rejection of miracles was based precisely on the claim that evidence from testimony would never be stronger than evidence from experience, and so belief in miracles from testimony of them is not justified. Turnbull, on the other hand, believed that the testimony given in the gospels was in fact enough evidence, and it is his argument that I want to focus on for the rest of today’s post.
In the conclusion to his Principles of Christian Philosophy (1749) Turnbull claims that he will show that “the christian revelation gives a very proper, full, and truly philosophical evidence for the truth of that doctrine concerning God, providence, virtue, and a future state. As I mentioned earlier, Jesus and his apostles had a first hand access to the evidence, i.e. the works and miracles of Jesus Christ. But what we have access to is testimony of that evidence, and not the evidence itself. This being the case, we must wonder if testimony is reliable enough. In an earlier section of his book, Turnbull argues that testimony, whether of the senses, or of introspection, or of whatever kind, must be examined under the same criteria:
- “[E]xperiences taken upon testimony, must all of them, whether concerning objects of the outward senses, or inward sentiments, operations, and affections of the mind, be tried, examined, and admitted, or repelled by the very same criteria, or rules of moral evidence.”
So the testimony from the gospels should be examined the same way we examine any testimony of experiments in natural philosophy. Turnbull then claims that we have no reason to doubt the testimony whether of Jesus or the apostles, just as we wouldn’t doubt the testimony of a skilled scientist:
- “For surely, one who had admitted the truth of a proposition in geometry, or of an experiment in natural philosophy, upon the testimony of one skill’d in these arts, in whom he had reason to confide, has no ground to doubt such testimony, when having made further advances in geometry or experimental philosophy, he comes to see the truths he had formerly received upon testimony, as it were, with his own eyes. And must not the same hold true with respect to moral truths?”
It seems that Turnbull does not confront the issue of the reliability of testimony as proper evidence. Of course, he could argue that we do not have any reason to doubt the account given by the apostles because they are characterized as having a virtuous moral character, and so is Jesus. But these accounts come from the gospels themselves, so unless we have an external account of the moral character of those giving the testimony, it seems that we might have grounds to doubt them.
Turnbull, however, seems to think that this is not an issue and that in fact “the enemies of Christianity have in no age ever attacked the evidence” for the history of Jesus Christ. In particular, Turnbull argues that the main reason to accept the evidence from testimony is the fact that it is not inconsistent with the knowledge we gain from our observation of the natural world. The main purpose of Turnbull’s text is to show that revealed religion confirms the knowledge accessed from natural religion, and it is in this sense that the former is useful. So as long as testimony agrees with experience, there is no reason to reject it.
- “Surely it cannot be said, that because one kind of evidence for a truth is good, that therefore another kind of evidence is not good. And therefore the evidence in such a case must stand thus. ‘Here is a double evidence for certain truths; an evidence from the nature of things; an intrinsick evidence; and likewise an extrinsick evidence, or an evidence from testimony, upon which there is a sufficient reason to rely independently of all other considerations.'”
It appears then that the testimony of the gospels is just a different kind of evidence for the Christian doctrines, and since it confirms the claims we have deduced from our experience of the world, then such testimony is reliable. Turnbull can only claim that testimony is reliable after proving the doctrines from natural religion, i.e. by examining the world and the workings of our mind. So Turnbull’s strategy is not to argue for the reliability of testimony itself, but rather to claim that since it is not inconsistent with what we have learnt from experience, then there is no reason to reject it.
The demise of Spinozism and the rise of Dutch experimental philosophy
A guest post by Wiep van Bunge.
Wiep van Bunge writes…
Rienk Vermij has demonstrated quite convincingly that the first Dutch Newtonians were actively engaged in countering the threat Spinoza posed (Vermij 2003). A crucial moment in the simultaneous demise of Spinozism and the rise of experimental philosophy was Bernard Nieuwentijt’s publication, in 1715, of his famous Het regt gebruik der wereldbeschouwingen – translated into English, French and German. Nieuwentijt specifically marked out Spinoza’s atheism as his main target, inspiring many dozens of countrymen and many others abroad to discern the providential reign of a supernatural Creator, who was not to be identified with Nature in the way the Spinozists had been doing for several decades.
More interesting, however, is his posthumous Gronden van zekerheid, in which he further developed a number of comments on mathematics made by one of Spinoza’s earliest critics, the linguist and philosopher Adriaen Verwer in his 1683 refutation of Spinoza’s Ethics. Verwer had warned his readers against Spinoza’s confusion of entia realia, things that really exist, and entia rationis, things we can talk about coherently but which are only supposed to exist even though we are able to conceive of them clearly and distinctly. Spinoza’s fundamental error, according to Verwer, consisted in supposing that once a clear and distinct idea has been formed, the ideatum conceived of in the idea really exists (Verwer 1683; 1–5).
In Gronden van zekerheid Nieuwentijt first elaborates on the distinction between ‘imaginary’ (denkbeeldige) and ‘realistic’ (zakelijke) mathematics, that is between a mathematics concerned with abstract notions without any corresponding objects in reality, and a mathematics concerned with objects the reality of which has been established by experience. Thus Nieuwentijt attempts to ensure that the use of mathematical reasoning is reserved for the behaviour of natural, observable objects. After having demonstrated the benefits of a ‘realistic’ use of mathematics, Nieuwentijt in the fourth part of Gronden van zekerheid accuses Spinoza of being merely an ‘imaginary’ mathematician, who just made it look as if his abstract metaphysics had anything to do with the real world. In reality, or so Nieuwentijt felt, Spinoza was only talking about his own, private ideas. What is worse, Spinoza consciously refused to acknowledge the need to ascertain the correspondence of these ideas to any external reality, as is evident, Nieuwentijt continued, from Spinoza’s conception of truth. Neither was he prepared to check the truth of his ‘deductions’ against any empirical evidence, which led him to preposterous conclusions, such as regarding the human intellect as being a part of God’s infinite intellect as well as an idea of an existing body (Nieuwentijt 1720: 244ff).
Throughout Gronden van zekerheid Nieuwentijt points to the obvious alternative to Spinoza’s ‘figments of the imagination’: the experiential ‘realistic mathematics’ adopted by the Royal academies of Britain, France and Prussia as well as by countless serious scientists across Europe. Philosophy, Nieuwentijt contended in the fifth and final part of his book, should become a ‘realistic metaphysics’ (sakelyke overnatuurkunde), which rests on the same foundations that realistic mathematicians build on: faith in the revealed Word of God and experience, to which he adds that philosophers are often best advised to suspend judgment because we simply lack the data necessary for answering many of the question traditionally raised by metaphysicians (Nieuwentijt 1720: 388ff). Newton, ‘the mathematical Knight’, had shown the way by setting up experiments in order to confirm the truth of conclusions arrived at by means of deduction and by making sure that the general principles from which these conclusions derived were the result of ‘empirical’ induction (Nieuwentijt 1720: 83–84; 188 ff). In addition, Nieuwentijt was happy to confirm that Newton’s work clearly established the providential reign of the Creator over His creation, making it an ideal weapon in the fight against atheism (Nieuwentijt 1720: 228).
It would seem, then, that in Nieuwentijt’s eyes, and Verwer appears to have been of the same opinion, Spinozism was actually a philosophical instance of ‘enthusiasm’ – not unlike the German theologian Buddeus’ earlier suggestion (Buddeus 1701: 15–16). Both were appalled to read that according to Spinoza ideas were true to the extent that he himself felt them to be true, instead of checking their correspondence to the world as we know it. Thus Nieuwentijt continued an Aristotelian and humanist tradition according to which ‘contemplative philosophy’ represented a type of ‘philosophical enthusiasm’ (Heyd 1995: Ch. 4).
Buddaeus, I.F., Dissertatio philosophica de Spinozismo ante Spinozam (Halle, 1701).
Heyd, Michael, ‘Be Sober and Reasonable’. The Critique of Enthusiasm in the Seventeenth and Early Eighteenth Centuries (Leiden, 1995).
Nieuwentijt, Bernard, Het regt gebruik der wereldtbeschouwingen, ter overtuiginge van ongodisten en en ongelovigen aangetoont (Amsterdam,1715).
–, Gronden van zekerheid, of de regte betoogwyse der wiskundigen, So in het denkbeeldige als in het het zakelyke (Amsterdam, 1720).
Vermij, Rienk, ‘The Formation of the Newtonian Natural Philosophy. The Case of the Amsterdam Mathematical Amateurs’, The British Journal for the History of Science 36 (2003), 183–200.
Verwer, Adriaen,’t Mom-Aensicht der atheisterij afgerukt door een verhandeling van den aengeboren stand der menschen (Amsterdam, 1683).
Workshop: Early Eighteenth-century Experimental Philosophy in the Dutch Republic
The VUB’s Centre for Logic and Philosophy of Science and the National Committee for Logic, History and Philosophy of Science are proud to announce the international workshop:
Early Eighteenth-century Experimental Philosophy in the Dutch Republic.
Date: 7 July 2014
Venue: The Royal Academies for Science and the Arts of Belgium, Rubenszaal
Organizers: Steffen Ducheyne and Jip van Besouw
Programme:
8.15-8.40 a.m.: Welcome and coffee
8.40-8.45 a.m.: Introduction by Steffen Ducheyne (Free University Brussels)
8.45-9.30 a.m.: Lecture by Gerhard Wiesenfeldt (University of Melbourne): ‘Local traditions in the making of Dutch Newtonianism’
9.30-10.15 a.m.: Lecture by F. J. Dijksterhuis (University of Twente): ‘German traces in Dutch experimental philosophy’
10.15-10.45 a.m.: Coffee break
10.45-11.30 a.m.: Lecture by Steffen Ducheyne (Free University Brussels) ‘Aspects of Petrus van Musschenbroek’s appropriation of Newton’s natural-philosophical methodology’
11.30-12.00 a.m.: Presentation by Jip van Besouw (Free University Brussels) of the FWO-funded research project ‘In the footsteps of Isaac Newton? W. J. ’s Gravesande’s scientific methodology’
12.00-13.45 p.m.: Lunch break
13.45-14.30 p.m.: Lecture by Anne-Lise Rey (Université de Lille I): ‘Probability, moral certainty and evidence in Willem ’s Gravesande’s natural philosophy’
14.30-15.15 p.m.: Lecture by Tammy Nyden (Grinnell College, Iowa) ‘Experiment’s journey at Leiden: From compromise to justified scientific method’
15.15-15.45 p.m.: Coffee break
15.45-16.30 p.m.: Lecture by Ad Maas and Tiemen Cocquyt (Boerhaave Museum, Leiden): ‘The truth in a layer of clay: A replication of ’s Gravesande’s vis viva experiment’
16.30-17.00 p.m.: Concluding remarks by Eric Jorink (Huygens Institute for the History of the Netherlands and Leiden University)
Abstracts: download PDF here.
Attendance is free, but registration is mandatory. To register please send an e-mail to jip.van.besouw@vub.ac.be before 1 July.
Understanding Newton’s Experiments as Instances of Special Power
Kirsten Walsh writes…
In my last few posts, I have been discussing the nature of observations and experiments in Newton’s Opticks. In my first post on this topic, I argued that Newton’s distinction between observation and experiment turns on their function. That is, the experiments introduced in book 1 offered individual, and crucial, support for particular propositions, whereas the observations introduced in books 2 and 3 only supported propositions collectively. In my next post, I discussed the observations in more detail, arguing that they resemble Bacon’s ‘experientia literata’, the method by which natural histories were supposed to be generated. At the end of that post, I suggested that, in contrast to the observations, Newton’s experiments look like Bacon’s ‘instances of special power’, which are particularly illuminating cases introduced to provide support for specific propositions. Today I’ll develop this idea.
Note, before we continue, that there are two issues here that can be treated independently of one another. One is establishing the extent of Bacon’s historical influence on Newton; the other is establishing the extent to which Bacon’s methodology can illuminate Newton’s. In this post I am doing the latter – using Bacon’s view only as an interpretive tool.
Identifying ‘instances of special power’ (ISPs) was an important step in the construction of a Baconian natural history. ISPs were experiments, procedures, and instruments that were held to be particularly informative or illuminative. These served a variety of purposes. Some functioned as ‘core experiments’, introduced at the very beginning of a natural history, and serving as the basis for further experiments. Others played a role later in the process. They included experiments that were supposed to be especially representative of a certain class of experiments, tools and experimental procedures that provided interesting shortcuts in the investigation, and model examples that came very close to providing theoretical generalisations. In some cases, a collection of ISPs constituted a natural history.
The following features were typical of ISPs. Firstly, they were considered to be particularly illuminating experiments, procedures or tools. For example, a crucial instance, or a particularly clear or informative experiment, or experimental procedure. Secondly, they were supposed to be replicated. On Bacon’s view, replication was not merely an exercise for verifying evidence; it was an exercise for the mind, ensuring that one had truly grasped the phenomenon. Thirdly, they were versatile, in that they could be used in several different ways. As we shall see, the experiments of book 1 display these essential features.
In book 1 of the Opticks, Newton employed a method of ‘proof by experiments’ to support his propositions. Each experiment was introduced to reveal a specific property of light, which in turn proved a particular proposition. We know that Newton conducted many experiments in his optical investigations, so why did he present the experiments as he did, when he did? When we consider Newton’s experiments alongside Bacon’s instances of special power, common features start to emerge.
Firstly, for each proposition he asserted, Newton introduced a small selection of experiments in support – those that he considered to be particularly illuminating or, in his own words, “necessary to the Argument”. Unlike in his first paper, in the Opticks, Newton did not label any experiments ‘experimentum crucis’. But his use of terms such as ‘necessary’ and ‘proof’ make it clear that these experiments were supposed to provide strong support: just like ISPs.
Secondly, Newton usually provided more than one experiment to support each proposition. These were listed in order of increasing complexity and were carefully described and illustrated. That Newton took this approach, as opposed to just reporting on their results, suggests that these experiments were supposed to be an exercise for the reader: they were about more than just proof or confirmation of the proposition. The reader was supposed either to be able to replicate the experiment, or at least to understand its replicability. Starting with the simplest experiment, Newton led his reader by the hand through the relevant properties of light, to ensure that they were properly grasped. Like Bacon’s ISPs, then, Newton’s experiments were intended to be replicated.
Thirdly, Newton’s experiments were recycled in a variety of roles in the Opticks. For example, the experiments he used to support proposition 2 part II were experiments 12 and 14 from part I. Newton introduced and developed these experiments in several different contexts to illuminate and support different propositions. Again, this is typical of Bacon’s ISPs.
And so, Newton’s experiments in the Opticks play a role analogous to Bacon’s instances of special power, and thinking of them as such explains why they are presented as they are. They are particularly illuminating cases that are introduced to provide support for specific propositions. Newton selected the experiments which best functioned as ISPs for inclusion in the Opticks. Moreover, seen in this light, the seemingly disparate set of experiments start to look like a far more cohesive collection, or a natural history.
Many commentators have emphasised the ways that Newton deviated from Baconian method. Through this sequence of posts, I have argued that the Opticks provides a striking example of conformity to the Baconian method of natural history.
Workshop: Mathematics and methodology from Newton to Euler
University of Sydney
20 March, 2014
9:15-5:30
Program:
- 9.15 Katherine Dunlop (Texas): ‘Christian Wolff on Newtonianism and Exact Science’
- 10.45 Coffee
- 11.00 Peter Anstey (Sydney): ‘From scientific syllogisms to mathematical certainty’
- 12.30 Lunch
- 2.00 Kirsten Walsh (Otago): ‘Newton’s method’
- 3.30 Stephen Gaukroger (Sydney): ‘D’Alembert, Euler and mid-18th century rational mechanics: what mechanics does not tell us about the world’
- 5.00 Wind up
Location: Common Room 822, Level 8, Brennan MacCallum Building
Contact: Prof Peter Anstey
Phone: 61 2 9351 2477
Email: peter.anstey@sydney.edu.au
RSVP: Here
Margaret Cavendish: speculative philosopher
Peter Anstey writes …
Two years ago on this blog I addressed the ‘Straw Man Problem‘ for the distinction between experimental and speculative philosophy. The apparent problem, according to some critics of the ESD, is that there were no speculative philosophers in the early modern period. In my response to that problem I listed The Duchess of Newcastle, Margaret Cavendish, as one of the few advocates of speculative philosophy in seventeenth-century England and in this post I want to explore her views in a little more depth.
Cavendish wrote the most sustained critique of experimental philosophy in the seventeenth century. Her Observations upon Experimental Philosophy, comprising 318 pages, was first published in 1666 and went into a second edition in 1668. In this work Cavendish gives a critical reading of many works of the new experimental philosophy in order to justify her own speculative natural philosophy. Within her sights are Robert Boyle’s Sceptical Chymist (1661), Henry Power’s Experimental Philosophy (1664) and Robert Hooke’s Micrographia (1665).
It is interesting to compare Cavendish’s views in this work with those of the young Robert Boyle a decade earlier. As I pointed out in my last post, in his ‘Of Naturall Philosophie’ of c. 1654, Boyle claims that there are two principles of natural philosophy, the senses and reason. He plumps for the senses. Cavendish in her Observations acquiesces in the very same principles, but takes the opposing line: for her, reason trumps the senses.
What is important for our interests here is not only the direct contrast with Boyle’s embryonic experimental philosophy, but the manner in which, for Cavendish, the terms of reference for the choice are between experimental and speculative philosophy. The following extracts give a feel for her position:
I say, that sense, which is more apt to be deluded than reason, cannot be the ground of reason, no more than art can be the ground of nature: … For how can a fool order his understanding by art, if nature has made it defective? or, how can a wise man trust his senses, if either the objects be not truly presented according to their natural figure and shape, or if the senses be defective, either through age, sickness, or other accidents … And hence I conclude, that experimental and mechanic philosophy cannot be above the speculative part, by reason most experiments have their rise from the speculative, so that the artist or mechanic is but a servant to the student. (Cavendish, Observations, ed. O’Neill (Cambridge), p. 49, emphasis added)
experimental philosophy has but a brittle, inconstant, and uncertain ground. And these artificial instruments, as microscopes, telescopes, and the like, which are now so highly applauded, who knows but they may within a short time have the same fate; and upon a better and more rational enquiry, be found deluders, rather than true informers (ibid., p. 99)
And toward the end of a long discussion of chemistry and chemical principles she reiterates her conclusion:
if reason be above sense, then speculative philosophy ought to be preferred before the experimental, because there can no reason be given for anything without it (ibid., p. 241)
Cavendish’s Observations first appeared at a very sensitive time for the Royal Society, for it had been the subject of much criticism from without and was in the process of securing an apologetical History of the Royal-Society by Thomas Sprat.
Now, there is no doubt that some of the more prominent Fellows of the Society are in view in her critique. Yet, it is important that we do not over-extend the target of the Observations, for, it is very much aimed at experimental philosophy and hardly makes reference to the Royal Society at all. Within a year of its publication the Duchess was to make a famous visit to the Society and the correspondence that ensued does not suggest that Henry Oldenburg and others regarded her as a hostile critic of the Society. This reinforces the view that her focus was more specific, namely, experimental philosophy.
Interestingly, after Cavendish’s death the following lines appeared in A Collection of Letters and Poems (London, 1678) written in her honour:
Philosophers must wander in the dark;
Now they of Truth can find no certain mark;
Since She their surest Guide is gone away,
They cannot chuse but miserably stray.
All did depend on Her, but She on none,
For her Philosophy was all her own.
She never did to the poor Refuge fly
Of Occult Quality or Sympathy.
She could a Reason for each Cause present,
Not trusting wholly to Experiment,
No Principles from others she purloyn’d,
But wisely Practice she with Speculation joyn’d. (A Collection, p. 166, emphasis added)
This poem in which these lines appear was penned by the poet Thomas Shadwell, author of The Virtuoso. Shadwell presents the Duchess as holding to a more balanced view of the relative value of practice and speculation than is warranted from her writings. But the fact that he has singled this out is indicative of just how central was this issue to thinkers of the day.
History: “a school of morality to mankind”
Juan Gomez writes…
Throughout the last few years we have presented a number of posts on education and experimental philosophy in the Early Modern period. Peter Anstey and Alberto Vanzo have commented on teaching experimental philosophy (Desaguliers, Adams, and Meiners), Gerard Wiesenfelt delighted us with two posts on universities in seventeenth-century Europe (Sturm and de Volder), and I have discussed education in Aberdeen (Fordyce and Gerard) and England (Bentham). Today I want to contribute to our research on education by discussing Turnbull’s ideas on learning and virtue.
Even though scholars have recognized that there were significant developments in educational theory in the Early Modern Period, almost all of their accounts are French-centred and the only British author they refer to is Locke, due to his influential Some Thoughts Concerning Education (1693). Of course, the bulk of the educational treatises of the eighteenth century were produced by French authors (Voltaire, Rollins, Diderot, Condorcet, etc.), but this does not mean that important works on education were not being produced outside of France. Turnbull’s Observations upon Liberal Education (1742) is a salient example here. Turnbull (with the exception of a recent article by Tal Gilead) is hardly even mentioned in scholarly accounts of education in the eighteenth-century, despite the fact that his book on education had a considerable impact at the time. Besides having a clear influence on Alexander Gerard and the educational reforms in the Aberdeen universities after 1750, Turnbull also appears as a major influence in Benjamin Franklin’s Proposals Relating to the Education of the Youth in Pennsylvania (1749). Further, even though many of the ideas in Turnbull’s Education also appear in Locke and Rollins’ work, Turnbull’s commitment to the experimental methodology gives his text a unique feature among the educational works of the time.
Turnbull, like Locke and Rollins before him, firmly believes that the main goal of education is the teaching of virtue. This popular idea of the time takes on a unique development in Education, where Turnbull applies the experimental method to his pedagogical theory:
- …as with regard to the culture of plants or flowers, sure rules can only be drawn from experiment; so for the same reason, there can be no sure rules concerning education but those which are founded on the experimental knowledge of human nature.
So where are we to find the experiments Turnbull hints at? If the aim of education is the achievement of virtue, then those experiments must contribute to this same purpose. We have already discussed that paintings can take on this role. However, in Education the role of experiments is taken up by the example of teachers and of historical characters. Turnbull refers to Horace to illustrate this method of educating:
- For ’tis by examples that good and bad conduct, with their various effects and consequences, the strength and grace to which men, by proper diligence, may arrive, and the baseness and misery into which vice plunges, most strongly appear…This, indeed, is the moral lesson every more exalted example in the records of human affairs presents to us in the most striking light, and to which cannot be too early or too forcibly inculcated from fact and experience… The characters of the more considerable personages of moral history, will afford, to a judicious instructor, excellent opportunities of enforcing, of deeply riveting this important lesson upon young minds.
History takes a primary role in Turnbull’s theory of education, given that it furnishes us with the experiments that allow us to direct the mind towards virtue. In another of his texts, a preliminary discourse to a translation of Justin’s History of the world (1742), Turnbull paraphrases Rollin to illustrate the priority of teaching history:
- History therefore, when it is well taught, becomes a school of morality to mankind, of all conditions and ranks. It discovers the deformity and fatal consequences of vices, and unmasks false virtues; it disabuses men of their popular errors and prejudices; and despoiling riches of all its enchanting and dazzling pomp and magnificence, demonstrates by a thousand examples, which are more persuasive than reasonings, that there is nothing truly great or praise-worthy, but untainted honour and probity.
Rollin and Turnbull share this belief in the supreme importance of history for teaching virtue, but unlike the former’s, Turnbull’s theory stands on his belief that the experimental method is the proper way of gaining any kind of knowledge. One of Turnbull’s original and interesting contributions to eighteenth-century educational theory is his interpretation of historical accounts as proper examples that provides us with adequate facts and observations for the instruction of virtue, in the same way experiments allow us to construct our conclusions in natural philosophy. Of course, the question of the accuracy of historical reports springs up; can inaccurate or false historical reports still contribute to the instruction of virtue? For example, an historical account that somehow illustrates that greed leads to happiness and the progress of society would not, presumably, be of service to the goal of education that Turnbull wishes. However, by insisting on the importance of the experimental method Turnbull has a way out: only those historical accounts that are founded on facts and observations are to be considered in the education of our youth. Turnbull did not deal with this issue in enough detail in Education, but he did discuss the issue of the reliability of historical reports in another context (religious testimony) which we will explore in my next post.
The formation of Boyle’s experimental philosophy
Peter Anstey writes …
It is not entirely clear when Robert Boyle (1627–1691) first used the term ‘experimental philosophy’, but what is clear is that his views on this new approach to natural philosophy began to form in the early 1650s, some years before the term came into common use.
Boyle’s earliest datable use of the term is from his Spring of the Air published in 1660. The reason for the lack of clarity about Boyle’s first use of the term arises from the fact that what appears to be a very early usage survives only in a fragment published by Thomas Birch in his ‘Life of Boyle’ in 1744: no manuscript version is extant. The context of Boyle’s reference to experimental philosophy in this text suggests that this fragment is associated with his ‘Essay of the Holy Scriptures’ composed in the mid-1650s. Boyle speaks of:
those excellent sciences, the mathematics, having been the first I addicted myself to, and was fond of, and experimental philosophy with its key, chemistry, succeeding them in my esteem and applications …
(Works of Robert Boyle, eds Hunter and Davis, London, vol. 12, p. 356)
However, the question of the precise dating of Boyle’s use of the term is hardly as significant as the formation of his views on his distinctive form of natural philosophy. And on this point we have some fascinating and chronologically unambiguous evidence, namely, Boyle’s outline of a work ‘Of Naturall Philosophie’ which dates from around 1654. This short manuscript in Boyle’s early hand survives among the Royal Society Boyle Papers in volume 36, folios 65–6. (It is transcribed in full in Michael Hunter, Robert Boyle 1627–1691: Scrupulosity and Science (Woodbridge, 2000), 30–1.)
In it Boyle outlines the two ‘Principles of naturall Philosophie’. They are Sense and Reason. As for Sense, in addition to its fallibility, Boyle stresses that:
it is requisite to be furnished with observations and Experiments.
Boyle then proceeds to give a set of seven ‘Directions concerning Experiments’. These directions provide an early adumbration of his later experimental methodology. They include the following:
1. Make all your Experiments if you can your selfe [even] though you be satisfyed beforehand of the Truth of them.
3. Be not discouraged from Experimentinge by haveing now & then your Expectation frustrated
5. Get acquainted with Experimentall Books & Men particularly Tradesmen.
7. After you have made any Experiment, not before, reflect upon the uses & Consequences of it either to establish truths, detect Errors, or improve some knowne or give hints of some new Experiment
As for the principle of Reason, Boyle gives five considerations concerning it. What is striking here is that each of them concerns the relation between Reason and experiments:
- That we consult nature to make her Instruct us what to beleeve not to confirme what we have beleeved
- That a perfect account of noe Experiment is to be looked for from the Experiment it selfe
- That it is more difficult then most men are aware of to find out the Causes of knowne effects
- That it is more difficult then men thinke to build principles upon or draw Consequences from Experiments
- That therefore Reason is not to be much trusted when she wanders far from Experiments & Systematical Bodyes of naturall Philosophie are not for a while to be attempted
Note here the caution about the difficulty of building natural philosophical principles from experiments and the warning about wandering from experiments and premature system building, points that were to become key motifs of the experimental philosophy that blossomed in the 1660s.
It may well be that the movement of experimental philosophy did not emerge until the early 1660s, but the conceptual foundations of its most able exponent were laid nearly a decade before.
Are there any parallel cases of natural philosophers who worked out an experimental philosophy in the early 1650s or was Boyle the first?
