Kirsten Walsh writes…
Recently, Zvi Biener and Eric Schliesser’s long-awaited volume, Newton and Empiricism, appeared on the shelves. The book is an excellent collection of papers, which makes a significant new contribution to the field. Today I want to focus on one aspect of this volume: the decision to frame the collection in terms of empiricism rather than experimental philosophy.
Over the last four years, we have provided many arguments for the superiority of the ESD over the RED. An important line of argument has been to show that ‘experimental philosophy’ and ‘speculative philosophy’ were the key terms of reference used by the actors themselves, and that they characterised their own work in terms of this division. For example, I have argued here, here, here and here that Newton is best understood as an experimental philosopher.
In their introduction, Biener and Schliesser explain their decision. They acknowledge the ‘Otago School’, and argue that, while in general there may be some good reasons to prefer the ESD to the RED, they see various problems with labelling Newton an ‘experimental philosopher’. Their concerns amount to the following: labelling Newton an ‘experimental philosopher’ obscures the idiosyncrasies of his approach to natural philosophy. They argue, firstly, that the label belies the significant influence of non-experimental philosophers on Newton’s methodology, for example those who influenced his mathematical focus. Secondly, that the label unhelpfully groups Newton with Boyle and Locke, when many features of his work support a different grouping. For example, Newton’s mathematical-system building suggests that his work should be grouped with Descartes’. Thirdly, they argue that the fact that Newton did not employ the label himself until after the publication of the first edition of the Principia suggests that he did not fully identify with the label.
These are important issues about the ESD and Newton’s place in it. So today I want to reflect on the broad problem of Newton’s idiosyncratic position. I argue that Newton’s divergence from Baconian tradition of the Royal Society is best seen as a development of experimental philosophy.
On this blog, I have sketched many features of Newton’s natural philosophical methodology. I have argued that, if we look at Newton from within the framework of the ESD, he can be neatly and easily identified as an experimental philosopher. His use of queries, his cautious approach to hypotheses, and his many methodological statements decrying the construction of metaphysical systems, suggest that this is a label that Newton would have been comfortable with. However, there is an important caveat to note: while Newton was clearly influenced by the Baconian experimental tradition, he did not consider himself a Baconian experimental philosopher.
In the earliest statements of his mathematico-experimental approach, Newton set up his position in opposition to the Baconian experimental philosophers. In these passages, one feature of Newton’s methodology stands out in explicit rejection of the Baconian method: his claims to certainty. This feature, in itself, is not very significant – many experimental philosophers believed that, in the end, natural philosophy would be a form of scientia, i.e. a system of knowledge demonstrated from certain axioms. Indeed, Bacon shared this ideal of certainty. He thought that his method of induction could get around the problems usually associated with ampliative inference and deliver knowledge of the essences of things. Thus, Bacon’s method of natural history was ultimately supposed to provide the axioms on which scientia could be founded. The challenge, which everyone agreed on, was to discover those axioms on which the system would be built.
Newton and the Baconians seem to diverge on their responses to this challenge. Baconian experimental philosophers recommended that one should have all the facts before formulating generalisations or theories. In contrast, Newton thought that a few, or even just one, well-constructed experiment might be enough – provided you used it in the right way. This shows that Newton took a different view of the role of evidence in natural philosophy. This divergence amounts to three key differences between Newton and the Baconian experimental philosophers:
- Where the Baconian experimental philosophers advocated a two-stage model, in which construction of natural histories preceded theory construction, Newton appeared to reject this two-stage approach. Newton commenced theory-building before his knowledge of the facts was complete.
- Related to (1), the Baconian experimental philosophers conceived of phenomena as immediate facts, acquired via observation, and hence pre-theoretic. In contrast, Newton’s phenomena were generalised regularities, acquired via mediation between observation and theory.
- For the Baconian experimental philosophers, queries were used to give direction and define the scope of the inquiry. But Newton’s queries were more focussed on individual experiments.
There is strong textual evidence that the ESD was operative in Newton’s early natural philosophical work. We have good reason to suppose that Newton regarded his natural philosophical pursuits as experimental philosophy. This becomes clearer in Newton’s later work. For instance, in the General Scholium to the Principia (1713), Newton explicitly described his work as ‘experimental philosophy’ – indeed, Peter Anstey has noted that Roger Cotes also recognised this feature of Newton’s work. We also have good reason to suppose that, in important ways, Newton saw his work as aligned with the Royal Society and, by extension, with the Baconian movement. But Newton was also a mathematician, and he saw a role for mathematical reasoning in experimental philosophy. In many ways, it was this mathematical approach that led to his divergence from the Baconian experimental philosophy.
Biener and Schliesser are right to draw attention to the ways in which Newton’s position diverged from the experimental tradition of the Royal Society. However, they fail to recognise that Newton’s position diverged in a way that should be viewed as a development of this tradition. Indeed, the ‘Newtonian experimental philosophy’ eventually replaced the experimental philosophy of Boyle, Hooke and the other early members of the Royal Society. The label ‘empiricism’ has no such historical relevance. But, more on this another time…
Kirsten Walsh writes…
In my last post, I considered the experimental support Newton offers for his laws of motion. In the scholium to the laws, Newton argues that his laws of motion are certainly true. However, in support he only cites a handful of experiments and the agreement of other mathematicians. I suggested that the experiments discussed do support his laws, but only in limited cases. This justifies their application in Newton’s mathematical theory, but does not justify Newton’s claims to certainty. In this post, I will speculate that the laws of motion were in fact better established than Newton’s discussion suggests. I introduce the notion ‘epistemic amplification’ – suggesting that Newton’s laws gain epistemic status by virtue of their relationship to the propositions they entail. That is, by reasoning mathematically from axioms to theorems, the axioms obtained higher epistemic status, and so the reasoning process effectively amplified the epistemic status of the axioms.
I am not arguing that epistemic amplification captures Newton’s thinking. In fact, Newton explicitly stated that epistemic gain was not possible. For him, the best one could achieve was avoiding epistemic loss. (I have discussed Newton’s aims of certainty and avoiding epistemic loss here and here.) I suggest that, objectively speaking, the epistemic status of Newton’s laws increases over the course of the Principia.
- The specification of the laws as the axioms of a mathematical system; and
- The justification of laws as first principles in natural philosophy.
Let’s consider the first project. In addition to the support of mathematicians and the experiments that Newton cites, it is plausible that the epistemic status of the laws increases by virtue of their success in the mathematical system: in particular, by entailing Keplerian motion. Kepler’s rules and Newton’s laws of motion have independent evidence: as we have seen, Newton’s laws are weakly established by localised experiments and the ‘agreement of mathematicians’; Kepler’s rules are established by observed planetary motion and were widely accepted by astronomers prior to the Principia. Newton’s laws entail Kepler’s rules, which boosts Newton’s justification for his laws. Moreover, Newton’s laws provide additional support for Kepler’s rules, by telling us about the forces required to produce such motions. The likelihood of the two theories is coupled: evidence for one carries over to the other. So Newton’s laws also boost the justification for Kepler’s rules. Thus, Newton achieves epistemic gain: the epistemic status of the laws, qua mathematical axioms, has increased by virtue of their relationship to Kepler’s rules.
Now let’s consider the second project – the application of the laws to natural philosophy. Again, the discussion in the scholium justifies their use, but not their certainty. I now suggest that these laws, as physical principles, gain epistemic status through confirmation of Newton’s theory. This occurs in book 3, when Newton explicitly applies his mathematical theory to natural phenomena. As I have previously discussed, the phenomena (i.e. the motions of the planets and their moons) are employed as premises in Newton’s argument for universal gravitation. However, the phenomena also support the application of the mathematical theory to the physical world: they show that the planets and their moons move in ways that approximate Keplerian motion. As we saw above, the laws of motion entail Kepler’s rules. So, since the phenomena support Kepler’s rules, they also support the laws of motion. So this is a straightforward case of theory-confirmation.
There is also scope for theory-testing in book 1. Each time Newton introduces a new factor (e.g. an extra body, or a resisting medium), the mathematical theory is tested. For instance, the contrasting versions of the harmonic rule in one-body and two-body model systems provides a test: it allows the phenomena to empirically decide between two theories, one involving singly-directed central forces, the other involving mutually-interactive central forces. Similarly, the contrasting two-body and three-body mathematical systems provide a test: they allow the phenomena to select between a theory involving pair-wise interactions and a theory involving universal mutual interaction. Moreover, in the final section of book 2, Newton shows that, unlike his theory, Cartesian vortex theory does not predict Keplerian motion. Thus, the phenomena seem to support his theory, and by extension the laws of motion, and to refute the theory of vortices. Again, the laws seem to gain support by virtue of their relationship to the propositions they entail.
To summarise, Newton claims that his laws are certainly true, but the support he gives is insufficient. Here, I have sketched an account in which Newton’s laws gain epistemic status by virtue of their relationship to the propositions they entail. ‘Epistemic amplification’ is certainly not something which Newton himself would have had truck with, but the term does seem to capture the support actually acquired by Newton’s laws in the Principia. What do you think?
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?
Juan Gomez writes…
In a number of posts in this blog we have examined how some philosophers in the eighteenth century were carrying out moral enquiries by following the experimental method that had achieved so much for natural philosophers. The subtitle of Hume’s famous Treatise clearly states the “attempt to introduce the experimental method in morals,” and we know that Turnbull, Butler and Hutcheson were also using this method in their arguments regarding morality, the human mind, and the existence of God. Regarding this latter issue, theistic philosophers like Butler and Turnbull argued that the order and perfection of the natural world (deduced from facts and observation) was clear proof of the wisdom and goodness of God. In this post I want to examine one of such arguments given not by a moral philosopher, but by a famous physician and mathematician: Dr. John Aburthnot.
Dr. Arbuthnot was a fellow of the Royal Society and Physician to the Queen, a fellow Scriblerian of Swift and Pope, a mathematician and a very interesting figure in general. Best known for his work in medicine and his satires, this fascinating polymath wrote a short paper that appeared in the Philosophical Transactions for 1710 titled “An Argument for Divine Providence, Taken from the Constant Regularity Observ’d in the Births of Both Sexes.” He explains how probability works in a situation involving a two-sided dice, and then proceeds to argue that the number of males and females born in England from 1629 to 1710 shows that it was not mere chance, but rather Divine Providence that explains the regularity between the sexes. Let’s examine his argument in more detail.
Arbuthnot begins by considering the purely mathematical aspect of an event where we want to find out the chances of throwing a particular number of two-sided dice (or a coin for that matter). The simplest case is that of 2 coins, where we have that there is one chance of both coins landing on heads, one chance of both coins landing on tails, and two chances where each of the coins lands on a different side. The mathematical details need not detain us here; the main conclusion drawn form this exposition is that the chances of getting an equal number of heads and tails grows slimmer as the number of coins augments. For example, the chances of this happening with ten coins is less than 25%. If instead of coins we consider all human beings which, Arbuthnott assumes, are born either male or female, the chances of there being equal number of each of the sexes are very, very low.
However, Arbuthnot acknowledges that the physical world is not equivalent to the mathematical, and this changes his calculations. If it was just mere chance that operated in the world, the balance between the number of males and females would lean to one or the other, and perhaps even reach extremes. But this is not the case. In fact, or so Arbuthnott argues, nature has even taken into account the fact that males have a higher mortality rate than females, given that the former “must seek their Food with danger…and that this loss exceeds far that of the other Sex, occasioned by Diseases incident to it, as Experience convinces us.” The wisdom of the Author of nature is witnessed in this situation, as the tables of births in England show that every year slightly more males than females are born, in order to compensate for the loss mentioned above and keep the balance. For example in 1629, Arbuthnot’s table list 5218 males to 4683 females; in 1659, 3209 males to 2781 females; in 1709, 7840 males to 7380 females; and so on for all the years recorded.
Arbuthnot concludes that from his argument “it follows, that it is Art, not Chance , that governs,” and adds a scholium where he states that polygamy is contrary to the law of nature.
What can we make of Arbuthnot’s paper? Instead of discussing how effective the argument is (I leave that for the readers to discuss with us in the comments!!), I want to focus on the fact that Arbuthnot’s argument illustrates the call for the use of mathematics in natural philosophy. Philosophers like Arbuthnot and John Keill thought that the use of mathematics had been neglected in natural philosophy and believed that it should play a greater role. From the 1690’s onwards the work of experimental philosphers reveals this use of mathematics in natural philosophical reasoning. The structure of Arbuthnot’s argument resembles that of the natural philosophers who, like Newton, were using mathematics to explain natural phenomena. The mathematical calculation is extrapolated to the case of human births (in this case). Arbuthnot recognizes an issue central to the application of maths in natural philosophy: while the former deals with abstract objects, the latter deals with the natural world. However, in this particular case Arbuthnot uses the asymmetry between the mathematical and physical realms to show that Divine Providence is a better explanation than mere chance when it comes to the balance and regularity of human births. I would like to hear what our readers think of arguments like the one constructed by Arbuthnot.
Peter Anstey writes…
In my last post I introduced Roger Cotes’ famous Preface to the second edition of Newton’s Principia in order to show its importance as an expression of a commitment to experimental philosophy. In that post I focused on Cotes’ critique of the Cartesian vortex theory and the manner in which this attack on the archetypal speculative philosophy formed the bookends of the Principia. In this post I will discuss the role of experiment in Cotes’ comments on experimental philosophy.
The Preface is actually quite a complex essay that has both polemical and expository agendas. On the one hand, Cotes uses it to give a summary of the main theses of the Principia centred around Newton’s theory of gravity. On the other hand, Cotes uses it to defend the theory of gravity against the charge that it is an occult quality, to defend Newton’s system of the world against the Cartesian vortex theory, and to defend the methodology of the work against rival approaches.
On this latter point, Cotes begins by claiming that Newton’s method is ‘based upon experiment’ (The Principia, eds I.B. Cohen and A. Whitman, Berkeley: University of California Press, 1999, p. 386). One might expect here that Cotes will give a list of the sorts of experimental results that Newton achieved or some reference to crucial experiments, but instead he introduces another set of methodological notions: phenomena, principles, hypotheses, analysis and synthesis. It is only later when appealing to various laws, principles and axioms in his summary of Newton’s system of the world that Cotes refers to experiments.
Here is a summary of Cotes’ account of the method of the Principia. Natural philosophy attempts to derive the causes of all things from the simplest of principles and not from contrived hypotheses. These principles are derived from the phenomena by a two-step process of analysis and synthesis. From select phenomena the forces and simpler laws of these forces are ‘deduced’ by analysis. Then by synthesis ‘the constitution of the rest of the phenomena’ is given. In the case of the Principia the relevant force is gravitational attraction and the relevant law is the inverse square law. Though Cotes throws in the laws of planetary motion claiming that ‘it is reasonable to accept something that can be found by mathematics and proved with the greatest certainty’ (p. 389). He also claims, after presenting a summary of the system of the world, ‘the preceding conclusions are based upon an axiom which is accepted by every philosopher, namely, that effects of the same kind –– that is, effects whose known properties are the same –– have the same causes, and their properties which are not yet known are also the same’. Indeed, ‘all philosophy is based on this rule’ (p. 391).
Where then do experiments fit in this picture? The first mention of experiments is in relation to the law of fall. Cotes refers here to pendulum experiments and to Boyle’s air-pump. Next, Huygens’ pendulum experiments are referred to in the discussion of the determination of the centripetal force of the moon towards the centre of the Earth (p. 389). They then appear in the elaboration of the ‘same effect, same cause’ axiom and its application to the attribution of gravity to all matter. Cotes says ‘[t]he constitution of individual things can be found by observations and experiments’ and from these we make universal judgments (p. 391). Thus, ‘since all terrestrial and celestial bodies on which we can make experiments or observations are heavy, it must be acknowledged without exception that gravity belongs to all bodies universally. … extension, mobility, and impenetrability of bodies are known only through experiments’ and so too is gravity. Finally, in recapping the Newtonian method near the conclusion of the Preface Cotes repeats that ‘honest and fair judges will approve the best method of natural philosophy, which is based on experiments and observations’ (p. 398).
What are we to make of the role of experiments here? First, notice how experiments are appealed to in the establishment of laws and the ‘same effect, same cause’ axiom. Second, it is worth pointing out that the ‘same effect, same cause’ axiom is Newton’s second rule of philosophizing: indeed, Cotes uses the very same example as Newton, namely, the falling of stones in America and Europe (see p. 795). Third, notice how without any explanation Cotes extends experiments to experiments and observations. He begins by saying that there are those ‘whose natural philosophy is based on experiment’ and he ends by saying that ‘the best method of natural philosophy, … is based on experiments and observations’. This is not an equivalent expression and while it is consistent with many other methodological statements by experimental philosophers, it still calls out for explanation.
Has Cotes really given an adequate summary of the method of experimental philosophy and has he captured the manner in which experiments are used in Newton’s reasoning in the Principia? In my view he has not. I’d be interested to hear your views?
Tammy Nyden and Mihnea Dobre write…
A while ago, we published an announcement on this blog of our forthcoming edited volume, Cartesian Empiricisms (Springer 2013). A claim in that post – that some Cartesians “seem to escape the ESD distinction” – has been questioned by Peter Anstey in another post. We thank him for the intervention and would like to push forward our claim and discuss it in more detail as this will reveal some of our concerns with the ESD (experimental-speculative distinction).
In his reply, Peter Anstey asked, “Did the Cartesians practise a form of experimental philosophy analogous to that of the Fellows of the early Royal Society?” We would argue that the question itself is problematic, as there are not two practices or worldviews to compare. There is variation among the Cartesians as well as among the fellows of early Royal Society. In order to gain a nuanced understanding of these historical actors, we suggest a rather different question: “What role did Cartesian philosophy play in the acceptance and spread of experimental practices in late seventeenth-century philosophy?” When we ask this question, we recognize the experiments of Robert Desgabets on blood transfusion, Henricus Regius on liquids, Burchard de Volder’s with air-pumps, etc., and consider how their work improved experimental technologies, influenced a theoretical reflection on the role of experiments and the senses in natural philosophy, and influenced institutional change that was favorable to experimental science.
Because Cartesians took various aspects of Descartes’ system and merged it with various aspects of experimentalism, there is not one ‘Cartesian’ use of experiment, but several. For example, both Regius and de Volder promoted experiment, but Regius rejects Descartes’ theory of innate ideas while de Volder defends it. Many Cartesians came to reject hyperbolic doubt, some defended vortex theory, some did not. Cartesian Empiricisms is not a complete inventory of such views expressed by Descartes’ followers. Rather our goal was to encourage the discussion of the above-mentioned question and to reveal some aspects that have been unfortunately neglected so far by both historians of philosophy and science.
Readers of this blog are familiar with the objection that traditional historiography of science was built on the Rationalist-Empiricist distinction (RED). A consequence is the exclusion of so-called “rationalists” from the histories of science, particularly history of the use, development and acceptance of experiment. This is problematic because recent research (e.g., Ariew, Lennon and Easton, Easton, Schmaltz, Cook, Nyden, Dobre, etc.) shows that many so-called rationalists were deeply involved in the practice and spread of the acceptance of experiment in natural philosophy. Cartesian Empiricisms gives further emphasis to this issue, as it examines several philosophers who identified as committed Cartesians who were deeply involved in experiment. According to historiographies that divide the period into two mutually exclusive epistemologies or methodologies these philosophers either do not exist (i.e., they are overlooked by histories of philosophy and science) or are seen as “not really Cartesian” or “not really experimentalist,” as it would be needed by that particular narrative. Thus, we do share the concern of the authors of this blog, that such binaries as RED force us to fit philosophers into categories that they would not themselves recognize and causes us to misrepresent seventeenth-century natural philosophy. Moreover, we acknowledge that this blog importantly shows the anachronism of the RED, a way of viewing the period that is constructed later by what may be called Kantian propaganda. However, we would like to raise now some of our concerns with the distinction promoted by this blog, the experimental-speculative distinction (ESD) and explain why some Cartesians would escape the ESD. Our worries cover two important aspects of the ESD: the label “speculative” and the actor-category problem.
(1) In a very recent post, Peter Anstey argued that eighteenth-century Newtonians pointed out Cartesian vortex theory as a prime representative of speculative philosophy (our emphasis). We caution against letting eighteenth-century Newtonian propaganda color a historical interpretation of seventeenth-century natural philosophy. Voltaire, d’Alembert and others took great pains to contrast Newtonianism from Cartesianism as two mutually exclusive worldviews who battled it out, with Newton’s natural philosophy as the victor. But the reality is that after Descartes’ death (1650) and before the victory of Newtonianism in the middle of the eighteenth century, followers of both Descartes and Newton had more in common than we are led to believe. More importantly, both “camps” had more diversity than we were ready to accept in the traditional histories. Cartesian Empiricisms draws attention to that diversity within Cartesianism. Perhaps the one thing Cartesians discussed in the chapters of this volume do have in common is that they do both experimental and speculative philosophy, as these two categories are sometimes defined on this blog. But this last claim leads to our second concern with the ESD.
(2) A reader of this blog will find that when ESD is compared to RED, the first advantage highlighted over the latter is that “the ESD distinction provided the actual historical terms of reference that many philosophers and natural philosophers used from the 1660s until late into the 18th century.” While there is no doubt that many early modern philosophers were using this language (i.e., “experimental” and “speculative”) in their writings, it is equally true that such language is not in use by the Cartesians. If one would be very strict with picking up “the actual historical terms of reference,” one will see another pair of terms keep mentioned by various Cartesians, “experience” and “reason.” Of course, one can read this pair as another form of the ESD, but that would be an interpretation, and a problematic one at that. Both the Cartesians and the so-called “experimentalists” were trying to determine the proper relationship between reason and experience and when one looks at their attempts, it becomes even more difficult to draw a clear line between speculative philosophers and experimentalist philosophers.
Our concern is the possible danger of transforming ESD into a new RED. Experimental and speculative may be useful adjectives to describe aspects of a particular philosophy or particular commitments of a philosopher (especially when the two terms are clearly stated in one’s writings). However, they are not useful for dividing philosophers or their natural philosophies, particularly when they are not already conceived as falling within the “experimental philosophy” camp, as is the case for Cartesians at the end of the seventeenth century.
Kirsten Walsh writes…
In my last post, I considered the phenomena in book 3 of Newton’s Principia. Newton’s decision to label these propositions ‘phenomena’ is puzzling, as they do not seem to fit any standard definition of the term. In this post, I’ll consider Bogen & Woodward’s (1988) distinction between data, phenomena and theories, and suggest that it sheds light both on Newton’s use of ‘phenomena’ and on the connection between his methodology in Opticks and Principia.
Bogen & Woodward (B&W) have argued for a 3-level picture of scientific theories in which:
- ‘Data’ are records produced by measurement and experiment that serve as evidence or features of phenomena. E.g. bubble chamber photographs, and patterns of discharge in electronic particle detectors.
- ‘Phenomena’ are features of the world that in principle could recur under different contexts or conditions. E.g. weak neutral currents, and the decay of a proton.
- ‘Theories’ are explanations of the phenomena.
B&W argue that theories explain phenomena, but not data. Data usually reflect many causal influences besides the explanatory target, while phenomena typically reflect single, or small, manageable numbers of causal influences. For example, General Relativity explains the phenomenon of bending light, but doesn’t explain the workings of the cameras, optical telescopes, etc. that causally influence the data.
Can we characterise Newton’s phenomena in terms of these three levels of theory? Let’s consider phenomenon 1:
- “The circumjovial planets, by radii drawn to the centre of Jupiter, describe areas proportional to the times, and their periodic times – the fixed stars being at rest – are as the 3/2 powers of their distances from that centre.”
In his discussion of this phenomenon Newton explained, “This is established from astronomical observations.” He provided the following table:
These observations are not data in the ‘pure’ sense that B&W discuss. Rather, they are generalisations: average distances and calculated periods of orbit. Moreover, the bottom row contains the average distances calculated from the period and the Harmonic rule (that the periods are as the 3/2 power of the semidiameters of their orbits). These calculations illustrate the ‘fit’ between the expected distance and the observed distance. Nevertheless, they provide a good example of how we might get from a set of data to a phenomenon. So perhaps we can think of them as ‘data’ in a methodological sense: they are records from which phenomenal patterns can be drawn.
I have another reason for considering these calculations ‘data’ in B&W’s sense of the term. In his discussion of phenomenon 1, Newton indicated that these calculations reflect a number of causal influences besides gravity. For instance, he explained that the length of the telescope affected the measurement of Jupiter’s diameter, because
- “the light of Jupiter is somewhat dilated by its nonuniform refrangibility, and this dilation has a smaller ratio to the diameter of Jupiter in longer and more perfect telescopes than in shorter and less perfect ones.”
This is a nice illustration of B&W’s notion of the shift from data to phenomena. By attending to his theory about telescopes, Newton was able to manipulate the data to control for distortion.
Now let’s consider the role of phenomenon 1 in Principia. Phenomenon 1 is employed (in conjunction with proposition 2 or 3, book 1, and corollary 6 to proposition 4, book 1) to support proposition 1, theorem 1, book 3:
- “The forces by which the circumjovial planets are continually drawn away from rectilinear motions and are maintained in their respective orbits are directed to the centre of Jupiter and are inversely as the squares of the distances of their places from that centre.”
This theorem doesn’t contain any information about the sizes or positions of the satellites of Jupiter, or about the workings of telescopes. So, while it explains the phenomenon, it gives no direct explanation of the data. This suggests that, in the Principia, data and phenomena are methodologically distinct.
B&W’s distinction between ‘data’ and ‘phenomena’ reveals two methodological features of Newton’s phenomena:
Firstly, Newton’s phenomena are explananda, but not appearances. Traditionally, ‘phenomenon’ seems to have been synonymous with both ‘appearance’ and ‘explanandum’. For example, the ancient Greeks were concerned to construct a system that explained and preserved the motions of the celestial bodies as they appeared to terrestrial observers. 2000 years later, Galileo and Cardinal Bellarmine argued over which system, heliocentric or geocentric, provided a better fit and explanation of these appearances. This suggests that, traditionally, there was no real difference between phenomena and data. For Newton, however, these come apart. The six phenomena of Principia describe the motions of celestial bodies, but not as they appear to terrestrial observers. In this sense, they are not appearances, but they do require an explanation.
Secondly, this reveals a continuity in Newton’s methodology. The point of Newton’s articulation of ‘phenomena’ in Principia is the same as his experiments in Opticks. Both identify and isolate a pattern or regularity. In the Opticks, Newton isolated his explanatory targets by making observations under controlled, experimental conditions. In Principia, Newton isolated his explanatory targets mathematically: from astronomical data, he calculated the motions of bodies with respect to a central focus. Viewed in this way, Newton’s phenomena and experiments are different ways of achieving the same thing: isolating explananda.
These considerations are admittedly speculative, so I’m keen to hear what our readers think. Does this look like a good way of characterising Newton’s phenomena?
A guest post by Michael Bycroft, a PhD Student at Cambridge.
Michael Bycroft writes…
In a recent post Peter Anstey asked: “When did the French embrace experimental philosophy?” In this post I want to do two things. One is to draw attention to two Frenchmen who practised experimental natural philosophy (ENP) well before Jean-Antoine Nollet began teaching this method in the mid-late 1730s. These men were René Réaumur and Charles Dufay. My other task is to try to explain why these men, who did so much to practice ENP, did so little to explicitly define or defend their practice.
René Réaumur (1683-1757) was arguably the most active and influential member of the Académie des Sciences in the first half of the eighteenth century. Nowadays he is known for his research on insects, steel-making, and thermometry, but his interests were truly encyclopaedic. Charles Dufay (1698-1739) is known to historians of physics as a student of electricity, but his research interests were nearly as broad as those of Réaumur, his patron and collaborator.
There is no doubt that these two men practiced ENP. It is true that they were Cartesians, in the sense that their chief theoretical resources were vortices and subtle fluids. But they wore their theory lightly, and they saw themselves primarily as experimenters rather than as system-builders. This pair was at least as committed to ENP, and in some cases more so, than their French colleague Nollet or their English counterparts Francis Hauksbee the Elder and John Desaguliers.
Yet it is hard to find clear, succinct, accessible endorsements of the key tenets of ENP in the writings of Dufay and Réaumur. Such endorsements do exist, but they are invariably buried in the middle of one or other of the many papers they published in the Académie’s journal, the Mémoires de l’Académie Royale des Sciences. Here is an example from one of Réaumur’s first papers, on the growth of shells, published in the 1709 volume of the Mémoires:
- But conjectures such as these [ie. the ones Réaumur had just advanced in the first part his paper] are not enough in true natural philosophy. Experiments performed on the matters at hand are the only sound basis for our reasoning…It is to experiments that I shall turn to decide whether I have correctly described the manner in which nature behaves, or whether [instead] everything I have said is merely a trick of the imagination.
- Mais de pareilles conjectures ne suffisent point en bonne Physique. Les seules expériences faites sur les choses dont il est question, y doivent servir de bases à nos raisonnemens. … C’est aux experiences que je vais rapporter à faire voir, si j’ai véritablement décrit la maniere dont la Nature agit, ou si l’on doit regarder tout ce qu’on vient d’avancer comme un simple jeu d’imagination.
This statement is clearly in the spirit of ENP, and similar statements can be found elsewhere in Réaumur’s papers, and in Dufay’s. But they are fleeting asides rather than stand-alone manifestos. Why were these men so reticent?
An important part of the answer is that the stand-alone manifestos of Nollet, Hauksbee and Desaguliers appear in the prefaces of their natural philosophy textbooks, and Dufay and Réaumur did not write textbooks. They did not need to. They were independently wealthy, drew sizeable pensions from the Academy, and were well-rewarded by the state for their research on French industries such as steel and textiles.
Perhaps it is also relevant that Bernard le Bovier de Fontenelle, the Perpetual Secretary of the Academy, did much to define and defend the Academy’s activities on behalf of its members.
Another factor may be that Dufay and Réaumur were more concerned to defend the application of natural philosophy to industry (against skeptical artisans and ministers) than they were to defend the application of experiment to natural philosophy (against speculative philosophers). At any rate, the former concern dominated the preface to Réaumur’s first book, L’art de convertir le fer en acier (1722).
Finally, as we have seen, Dufay and Réaumur dispensed methodological advice in the course of the papers they published in the Academy. Perhaps they considered this the best forum for expressing their views on ENP, even though this choice makes their views harder for the historian to identify than if they had written textbooks or dictionary entries instead.
This is not to say that Dufay and Réaumur had no connections with earlier and later textbook writers on ENP in France. On the contrary. They both learned much of their physics from Jacques Rohault’s Traité de physique, and in their turn they taught Nollet much of what he knew about experimentation (Nollet assisted both Dufay and Réaumur in their laboratories in the early 1730s). These connections reinforce the broader lesson of this post, which is that the leading practitioners of ENP were not always its most explicit promoters.
Alberto Vanzo writes…
In my last post, I raised the question as to whether there is any methodological view that was shared by all or most early modern experimental philosophers. To paraphrase Bas Van Fraassen, is there any statement E+ such that
- To endorse the method of (early modern) experimental philosophy = to believe that E+ (the experimentalists’ methodical dogma)?
As those of you who have followed this blog for a while will know, early modern experimental natural philosophers claimed that we should reject hypotheses and speculations (that is, roughly, natural-philosophical claims and theories) and rely instead on experiments and observations. In this post, I will discuss whether this claim, suitably understood, is the experimentalists’ methodical dogma. What does their rejection of hypotheses amount to?
The statement that we should reject hypotheses does not mean that we should avoid learning natural-philosophical claims and theories. On the contrary, according to Robert Hooke, learning hypotheses is beneficial because it helps us to devise new explanations and raise questions:
- the Mind will be somewhat more ready at guessing at the Solution of many Phenomena almost at first Sight, and thereby be much more prompt at making Queries, and at tracing the Subtilty of Nature, and in discovering and searching into the true Reason of things […]
Experimental philosophers also allow us to entertain claims and theories for the sake of testing them. Robert Boyle states in a letter to Oldenburg that natural histories should include “Circumstances” such that their “tryal or Observation” is “necessary or sufficient to prove or to invalidate this or that particular Hypothesis or Conjecture”.
Boyle’s statement makes clear that he allows for the acceptance of a natural-philosophical claims that are proven by “tryal [experiment] or Observation”. The claims in question must be those that are expressed by substantive or – in Kantian terms – synthetic a posteriori statements. Experiments and observations cannot prove analytic a priori statements. These are hardly the kind of statements that concerned experimental philosophers. Assuming that the analytic/synthetic distinction is tenable, accepting analytic a priori statements as true seems to be a harmless move anyway.
In the light of this, we may be tempted to paraphrase the rejection of hypotheses as follows:
- [A] Only commit to those substantive (as opposed to analytic) claims and theories that are warranted by experiments or observations.
[A] is in line with experimental philosophers’ rejection of arguments from authority, epitomized by the motto of the Royal Society: “nullius in verba“, which can be loosely translated as “take no man’s word for it”. [A] entails the rejection not only of arguments from authority, but also any kind of a priori arguments for substantive natural-philosophical claims – for instance, the arguments that Descartes used in the Principles of Philosophy to establish that material objects are made up of corpuscles. [A] has the welcome effect of classifying Descartes where, in my view, he belongs: outside of the movement of experimental philosophy, even though he too gathered natural-philosophical observations and performed some experiments.
However, [A] is inconsistent with the fact that many experimental philosophers were committed to substantive claims, like the corpuscularian and mechanist hypotheses, that were hardly warranted by the then extant empirical evidence. Boyle or Montanari did not seem to be concerned to provide detailed empirical arguments for corpuscularism or mechanism. However, they did not regard their acceptance of these views as being inconsistent with their commitment to experimentalism.
In view of this, I suggest replacing [A] with [B]:
- [B] Only firmly commit to those substantive claims and theories that are warranted by experiments and observations
and claiming that experimental philosophers like Boyle and Montanari did not firmly commit to corpuscularism and mechanism. They only weakly, tentatively, provisionally commit to these views, even though they were confident that future discoveries would dispel any doubt on their truth.
Is it correct to say that experimental philosophers’ commitments to mechanism and corpuscularism was typically weak, provisional, tentative? Are there other claims on the natural world that experimental philosophers firmly endorsed, even though the then available empirical evidence did not warrant them? Can a clear distinction between weak, provisional, tentative and strong, definitive, firm commitments be drawn, and if so, how? If you have any suggestions on how these questions should be answered, please let me know in the comments or get in touch. Answering these questions is important to establish if my suggestion that [B] represents a suitable candidate for the experimentalists’ methodical dogma is persuasive.
Peter Anstey writes …
In my last post we met the instrument maker and promoter of experimental philosophy Francis Hauksbee the Elder. Hauksbee, however, wasn’t the first lecturer to give public lectures in England on the exciting new developments in natural philosophy. That honour rests with a Scotsman called John Keill.
John Keill (1671–1721) came under the tutelage of the first Newtonian David Gregory in Edinburgh. He followed Gregory to Oxford in 1691 and by 1699 was giving lectures. Around 1704/95, according to his student John Theophilus Desaguliers, Keill became ‘the first who publickly taught Natural Philosophy by Experiments in a mathematical Manner’ (A Course of Experimental Philosophy, Volume 1, 1734, Preface). His lectures were published in Latin in 1702 and in English translation in 1720 under the title of An Introduction to Natural Philosophy: or, Philosophical Lectures read in the University of Oxford Anno Dom. 1700.
It is not clear, however, that Keill saw himself as teaching experimental philosophy. Some scholars have claimed that Keill was appointed as a lecturer in experimental philosophy at Oxford in 1704 and that he was the first to teach experimental philosophy there. Indeed, in 1707 The Oxford Intelligencer advertised his ‘Course of Mechanical and Experimental Philosophy’. Moreover, in the preface to his Introduction to Natural Philosophy he does express his opposition to speculative natural philosophy, particularly Cartesianism, singling out the Cartesian theory of gravity for particularly harsh treatment (pp. iv–vii).
Hence, one might naturally assume that he is a straightforward advocate of experimental philosophy, and yet this is not the case. For, in the first lecture Keill proceeds to distinguish four ‘Sects of Philosophers’: the Pythagoreans and Platonists; the Peripatetics; those who ‘proceed upon Experiments; and the Mechanical’ (pp. 1–3). He then informs the reader that ‘Amongst these various ways of Philosophizing, there is no particular one, wherein we do intirely acquiesce’ (p. 3). In fact, Keill saw himself as pursuing, not the new experimental philosophy, but what he calls ‘Mathematical Philosophy’ inspired by Newton and characterized by ‘applying Geometry to Natural Philosophy’.
As for experimental philosophy, Keill warns that:
- many of the Experiments that the third Sect of Philosophers [experimental philosophers] have delivered down to us, must be made use of: tho this ought not to be done without great Caution; for we are well apprised how fond these Gentlemen are of their Theories, how willing they are that they should be true, and how easily they deceive both others and themselves, in trying their Experiments (p. 7).
It is clear from this passage that Keill’s conception of what constitutes an experimental philosopher differs from that of Boyle and others, for Keill finds them too fond of their theories, whereas what characterises the experimental philosophers throughout the latter decades of the seventeenth century is their extreme caution in making any theoretical commitments until the observational and experimental data is assembled. Keill’s experimental philosopher would be foreign to most who aligned themselves with the movement.
The method that Keill follows instead is that of ‘The great Philosopher of this age, the most Ingenious and Incomparable Mr. Newton’ who ‘by his great and deep skill in Geometry’ was able to show the inconsistencies of Descartes’ vortex theory. Keill’s opponents in natural philosophy were not the speculative philosophers but ‘our ungeometrical Philosophers’ (p. 24). Thus Keill is representative of the first generation of those, like John Arbuthnot and John Harris who, inspired by Newton, adopted a straightforwardly mathematical approach to natural philosophy. Surprisingly, Keill’s reservations about experimental philosophy were completely ignored by the likes of Hauksbee the Elder and Desaguliers who preferred to see their efforts in promoting experimental philosophy as following Keill’s example and, in Desaguliers’ case, even recycling some of his lectures.