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Early Modern Experimental Philosophy
A project of the Early Modern Thought Research Theme at the University of Otago

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

Peter Anstey writes …

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

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

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

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

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

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

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

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

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

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

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

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

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

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


Kant’s Campaign against the Synthesis of Empiricism and Rationalism

This is a guest post by Timmy de Goeij. Timmy is part of a research project “Thinking classified – Structuring the world of ideas around 1800”, based at Utrecht University. We are grateful to Timmy for sharing his current research on our blog.

Kant is generally considered to be the first philosopher who synthesized early modern rationalism and empiricism, and who, with this synthesis, set the terms of reference for much of nineteenth and twentieth century philosophy. Contrary to this view, I am currently writing a paper wherein I argue, first, that Kant never thought of himself as providing a synthesis of rationalism and empiricism but as providing a middle road between dogmatism and scepticism, and, second, that this middle road is provided precisely by rejecting the syntheses of rationalism and empiricism that he saw present in the dogmatic and skeptical traditions. Although the second of these theses is certainly more exciting, I will first need to shortly elaborate on the first thesis, and postpone a discussion of the second one to a later post.

A couple of simple searches through the works of Kant will reveal immediately that he never explicitly characterized his philosophy in terms of a synthesis of rationalism and empiricism. As has been argued on this blog, it was Reinhold who first propounded this reading of Kant’s critical philosophy – a reading which was then probably adopted by Wilhelm Gottlieb Tenneman in his History of Philosophy, but which actually took a far longer period of time to become the standard narrative in the historiography of philosophy. In “Kant on Empiricism and Rationalism”, Alberto Vanzo emphasized the fact that there are many passages spread throughout Kant’s works wherein he more or less explicitly sides with the rationalist tradition in his theoretical philosophy, ethics and aesthetics. However, important in this regard is Kant’s distinction between an immodest or dogmatic empiricism and a more moderate or scientific form of empiricism.

Immodest empiricism adopts “a principle of pure empiricism, not only in the explanation of appearances in the world, but also in the dissolution of the transcendental ideas of the world-whole itself” (A466/B494), whereas modest empiricism only adopts a principle of empiricism in the explanation of the phenomena in the sensible world and limits our speculative knowledge (Wissen) to this domain of sensible objects (A470-471/B498-499). Kant’s doctrine of the categories alone already implies a rejection of the immodest form of empiricism. However, Kant does not reject the modest form of empiricism (ibid.). My hypothesis is that he reconciled empiricism and rationalism neither by synthesizing them, nor by finding a middle road between them, but by relocating and limiting their principles and methods to different domains of objects and knowledge. The claim of modest empiricism that our knowledge must follow the guidance of experience is valid for the phenomena in the sensible world, which is the proper domain of theoretical scientific knowledge. But empiricism must withhold from making any dogmatic claims about non-sensible objects and the transcendental conditions of the possibility of experience, because this is the pure domain of philosophy proper. In this way Kant conceptually prepares the separation between the empirical sciences and rational philosophy proper, guaranteeing the autonomy of both. Accordingly, Kant’s real battle was never with empiricism as such, nor with rationalism, but with the dogmatic forms of both empiricism and rationalism.

Throughout his works Kant also argues that scepticism itself was merely a reaction to dogmatism, and he situates his own philosophy as the middle road between dogmatism and scepticism (see, for example, Kant’s unfinished Progress of Metaphysics and the introductions to the third and eight parts of Metaphysik Vigilantius). In my view, then, Kant does not reject empiricism as such, nor is he concerned with synthesizing empiricism and rationalism; his critical philosophy tries to walk the middle road between dogmatism and scepticism. Moreover, my further hypothesis is that according to Kant’s own diagnosis, the failures of the dogmatic and skeptical traditions derive from mixing up empirical cognitions with rational cognitions, so that it “is of the utmost importance to isolate cognitions that differ from one another in their species and origin, and carefully to avoid mixing them together with others with which they are usually connected in their use” (A842/B870), and that this critical project is precisely meant to counter the syntheses of rational elements with empirical elements that were prevalent in both traditions. But that would be a topic for a later post.

Currently, I am still in the process of writing the paper, so I would appreciate any comments or suggestions either on the blog or via email.

Astrology and the novatores, part 2

Following my previous post on the status of astrology in early modern Spain, I want to give a more detailed account of the debate between Martin Martinez and Diego Torres de Villaroel. In today’s post I want to focus on the specifics of Martinez´s rejection of astrology in Juicio final de la astrologia (the final judgment of astrology).

As I commented last time, Martinez directs his attack against Diego Torres de Villaroel, a scholastic mathematician and astrologist famous for his almanacs. Martinez attacks the use of astrology on three fronts: its application in natural philosophy, in morals, and in politics. Let’s focus only on the first of these aspects here.

Martinez complains that, in order to enhance the reach of their discipline, astrologers have placed celestial bodies as the cause of almost all natural effects:

    …they [astrologers] confer to them [celestial bodies] the rains, winds, and all other alterations of the air. There is no metal in the depths of the earth that escapes their influence; they say Mars rules iron; the Moon rules silver, Jupiter rules tin, Saturn rules lead, Venus rules copper, and Mercury rues quicksilver… There is no animal, whether terrestrial, aquatic, or airborne, whose birth, life, and death does not depend on the judgment of the Celestial Bodies…even today, one or another Physician is possessed by this mistake, fixing to each celestial body its special qualities without ever experimenting them; just on their devotion, they make some hot and other cold; just on their word they make some dry and other wet; they assign a Planet to each body part: the Sun to the heart, the Moon to the brain, Mars to the liver, Saturn to the spleen, Venus to the kidneys, Jupiter to the uterus, and Mercury to the lungs…

Martinez first points out that, not being founded on experience, the conjectures of the astrologists lead to disagreements between them. One astrologist assigns the five moons of Jupiter to the fingers, while another assigns them to the five upper left teeth. Mocking the astrologists for the inconsistencies among their unfounded conjectures is only an initial stab at them, but Martinez has a more substantial philosophical argument behind it. The thrust of Martinez’s argument is that, given the presence of evident qualities, any reference to occult qualities can be nothing more than a fiction. The sun, the weather, and the observation of nature here on earth are enough to explain natural effects. There is no need to look for a connection between the celestial bodies and the ailments of the human body or the best times for harvest. The former are explained through medicine and the latter through natural philosophy, but astrology does not play any role in either.

To illustrate this, Martinez draws from natural phenomena and shows that natural philosophy always offers a better explanation than astrology. He refers to a particular event where we experience some warm days during winter as well as fresh days during summer. He emphasizes that not even the sun is a necessary cause of the seasons, but rather a sign of them. If the sun truly was the cause, then the temperature would gradually rise and decrease between the two solstices, and every year our summers and winters would be identical, given that the position of the sun is the same each year. So how do we explain the phenomenon? Astrologists, Martinez says, say that “the cold that we experience during summer is caused by the influence of the very cold Saturn, and the warm days during winter are due to the influence of raging Mars.” But if this were true, then this effect would be the same all across the globe, which is clearly false. Martinez refers to the different observations in Madrid and Valencia to illustrate the implausibility of the astrologists’ conjecture.

Natural philosophy offers a better explanation of this phenomenon: “the cause of these alterations is the variety of situations between Countries, and the variety of winds specific to each of them; since when the Austral blows in winter there is warmth, and when the Boreal blows in summer there is fresh climate…it is always necessary to refer to the specific constitution of the regions, and the diverse fermentations and other elemental alterations, in order to explain these phenomena, and reject the musings of the astrologists as unnecessary.”

Martinez drives the argument home by commenting on the superfluousness of consulting the stars when it comes to harvest:

    Of the rains and storms I say the same, since when there is an evident cause, it is not philosophical to refer to obscure causes…We must think in the same manner regarding the infertility and abundance of harvests: for if the farmer, by manuring a ground which is watered promptly by rain, collects a bountiful harvest, we must not look at any Celestial body for the cause but rather to his diligence and the prompt rain; in the same manner we must account for the infertility of harvest by a defectuous watering, small crops, the locust plague, or other evident causes; but it is never necessary to refer to Celestial Bodies to explain such events.

In essence, Martinez appeals to the astrologists’ unfounded conjectures and their appeal to obscure causes to reject the application of astrology in our explanation of natural phenomena. However, the popularity of almanacs in Spain and the confidence and reputation of figures like Torres de Villaroel meant that Martinez was facing a fierce opposition. In my next post we will examine Torres de Villaroel’s defence of astrology and his subsequent attack on the novatores.

Newton the empiricist?

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:

  1. 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.
  2. 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.
  3. 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…

James Bradley’s Lectures on Experimental Philosophy

Peter Anstey writes …

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

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

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

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

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

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

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

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

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

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

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

Astrology and the novatores

Juan Gomez writes…

In one of my previous posts regarding early modern Spain I referred to Martin Martinez, a physician who was an avid promoter of the experimental method. Today I want to examine a debate he had regarding the rejection of astrology. In this blog we have provided many illustrations of the methodological statements typical of those who promoted and adopted experimental philosophy. We have shown the insistence in rejecting the work of those that rely solely on speculation, but we have not yet seen any examples of the work of speculative philosophers. The case of astrology in 1720s Spain can shed some light on the kind of speculative science rejected by experimental philosophers like Feijoo and Martinez.

Besides the comments he added supporting Feijoo’s work, Martinez wrote a whole essay (Juicio final de la astrologia (The final judgment of astrology)) rejecting astrology in 1727. He distinguished between astronomy and astrology: while in the former “the regular movement of the stars is observed…times are computed, lunar cycles determined, and eclipses are predicted”, in the latter astrologists “feign a volume (only intelligible to them) in the heavens where they find written mundane events, wars, famine, pests, shipwrecks, harvests, diseases, and all other fortunes of human life.”

In the comments he makes defending Feijoo’s work, Martinez clarifies that the problem with astrology is that it is not founded in observation and experience:

“Upon reflection, according to what reasoning, or experience, do the astrologists found their imagined influxes of the stars and planets? On what grounds do they know that Mars burns, and Saturn cools? They probably say, because Mars is red and Saturn grey: though according to this they should also say that carnations burn and quicklime cools; and if they say they experience heat coming from Mars, I do not understand how they know it comes from it, and not from another cause.”

Martinez goes on listing a number of claims astrologists make, in particular related to the effects the movement of the planets and stars, eclipses, and comets have on the health of individuals. But Martinez is directing his claims to one individual in particular, Diego de Torres Villaroel, a mathematician and astrologist who published yearly almanacs with predictions under the pseudonym “el gran Piscator de Salamanca”. Leaving the calendars aside, Torres also published an essay containing his ideas on the nature of the earth and the heavens. The text was first published in 1724 under the title Viaje fantastico del gran Piscator de Salamanca (The fantastic journey of the great Piscator of Salamanca), and then again in 1739 as Anatomia de todo lo visible e invisible (Anatomy of all that is visible and invisible). It is this book that Martinez targets, and will serve as our illustration of the kind of speculative philosophy the novatores rejected.

Torres’ essay gives an account of the structure and composition of the earth and the heavens, all this prompted by an eclipse which occurred on May 22, 1724. The explanation of the constitution of both spheres of the universe (heaven and earth) is given through a story where the great Piscator travels to the depths of the earth and then upwards to the heavens, illustrating to his fellow travellers all the details of both spheres. As is clear from various passages, Torres’ claims are never supported by observations, but only by the musings of his mind and astrological calculations. The opening lines of the dedicatory epistle highlight the speculative nature of the work:


“Hand over hand the soul, without resorting to the use of the external senses, and reason, in arms of a jobless idleness, let fantasy to its word, and running through the spaces of imagination it recited in their theatre the following story.”

Torres acknowledges that he writes from his imagination, but asserts that he reaches the same conclusions others (like Kepler, who studies “the cosmic machine”) have:

“With no other guide but my imagination, and sleeping like a log, I have completed the same journeys [as Kepler and Kircher].”

Although lines like the ones just quoted give the impression that Torres must be speaking metaphorically, it seems that his ‘discoveries’ had no other foundation that the inspiration he got from studying astrology. In the opening lines of the story, a character contrasts the method of astrologists like Torres to those who studied the eclipse by means of observation:

“How is it that you, Mr. Astrologist, in an eclipse whose nature and effects have excited the North and their less lazy Observers have been writing about, you do nothing other than note down in your Prediction the simple calculation of the time and the day?”

Torres defends himself, and convinces his companions to go on a journey through the earth and the heavens in order to understand the nature of eclipses and their effects on human events. In their journey through the earth the astrologist points out where hell and purgatory reside deep down where there is no influence of the heavenly bodies. Then they travel upwards to the heavens, where the astrologist explains the different levels, how all is made of ether, and its effects on the earth. He explains how when a comet is “of the nature of Saturn”, it “causes colds, leprosy, haemorrhoids, paralyses, and chronic diseases”; if it is dominated by Mars on the other hand, it causes “cruel dysentery, rotten fevers, delirium, haemorrhages…”

I could go on drawing on passages from Torres’ book, but the ones quoted above are enough to illustrate the opposition to astrology that the Spanish novatores insisted on. It is important to remember that figures like Feijoo and Martinez had a genuine worry regarding the influence of astrology. Unlike our present time, in the early decades of the eighteenth century astrology was still considered by many as a genuine science, and it was this (more than the almanacs) that motivated the novatores to call for a ban on astrology.

Colloquium: Principles in Early Modern Thought

University of Sydney

27–29 August 2014



Engraved word map by Leonhard Euler

  • Professor Peter Anstey (Sydney), ‘Principles: the Contours of a Concept’ & ‘Principles of Religion’
  • Mr Joe Campbell QC (Sydney), ‘Principles & the Development of English Equity Law’
  • Professor James Franklin (UNSW), ‘Early modern Mathematical Principles’
  • Professor Daniel Garber (Princeton), ‘Principles in Leibniz’s Philosophy’
  • Professor Michael LeBuffe (Otago), ‘Principles of Spinoza’s Philosophy’
  • Professor William R. Newman (Indiana), ‘Chymical Principles’
  • Professor Sophie Roux (ENS, Paris), ‘Principles in French Philosophy’
  • Professor Kiyoshi Shimokawa (Gakushuin, Tokyo), ‘A Conflict of Principles: Hume versus Modern Natural Lawyers’
  • Dr Alberto Vanzo (Warwick), ‘Principles in Italian Natural Philosophy’
  • Ms Kirsten Walsh (Otago and Calgary), ‘Principles in Newton’s Natural Philosophy’


Colloquium Sponsors:

This colloquium forms part of Professor Peter Anstey’s ARC Future Fellowship project on ‘The nature and status of principles in early modern philosophy’. It is sponsored by the School of Philosophical and Historical Inquiry and the Sydney Centre for the Foundations of Science.


Colloquium Organisers:

  • Professor Peter Anstey
  • Professor Stephen Gaukroger


Places are limited.

Click here to register


Program (Download PDF of the program here):

Wednesday 27 August:

9.00           Peter Anstey, ‘Principles: the Contours of a Concept’

10.30         Coffee Break

11.00         James Franklin, ‘Early modern Mathematical Principles’

12.30         Lunch

1.30           Joe Campbell, ‘Principles & the Development of English Equity Law’

3.00           Break

3.30           William Newman, ‘Chymical Principles’

5.00           End of Day


Thursday 28 August:

9.00           Sophie Roux, ‘Principles in French Philosophy’

10.30         Coffee Break

11.00         Kiyoshi Shimokawa, ‘Principles of Natural Jurisprudence’

12.30         Lunch

1.30           Alberto Vanzo, ‘Principles in Italian Natural Philosophy’

3.00           Break

3.30           Peter Anstey, ‘Principles of Religion’

5.00           End of Day


Friday 29 August:

9.00           Michael LeBuffe, ‘Principles of Spinoza’s Philosophy’

10.30         Coffee Break

11.00         Kirsten Walsh, ‘Principles in Newton’s Natural Philosophy’

12.30         Lunch

1.30           Daniel Garber, ‘Principles in Leibniz’s Philosophy’

3.00           Conclusion

7.00           Colloquium Dinner


Location:   Darlington Centre H07, Boardroom

Contact:    Prof Peter Anstey

Phone:       61 2 9351 2477


Register: Here

‘Epistemic amplification’ and Newton’s laws


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.

To begin, recall that Newton has two projects in relation to the 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.

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?



An Update…

Hello, Readers!

On 23rd August 2010, we published our first post, presenting our research project to the world.  As ‘newbies’ to blogging, we weren’t quite sure how effective it would be.  Four years later, there is no trace of those initial doubts.  The capacity to regularly share new research has helped us to be productive, to keep abreast of each other’s work, and to grow as a team. Most of all, it has allowed us to engage with the wider community, and to receive feedback at a very early stage in our research.

In light of the project’s development, the nature of the blog will change somewhat. Our Marsden grant ended two years ago, and we have all gradually moved onto other new projects:

    Peter Anstey continues to work on early modern experimental philosophy, though he now has an additional cognate project on ‘The nature and status of principles in early modern philosophy’. He is currently an ARC Future Fellow at the University of Sydney where his principles project is based. He also continues to work on Locke, Boyle and Bacon.
    Alberto Vanzo is now a research associate at the Department of Philosophy at the University of Warwick. He is working on early modern experimental philosophy, Kant and the historiography of philosophy.
    Juan Gomez is still at the University of Otago, working as a casual lecturer and continuing his research on Early Modern Spain. He is in the process of developing an extensive research project regarding the introduction of experimental philosophy in Spain in the second half of the seventeenth century and the unique Spanish take on the methodological debate of the period.
    Kirsten Walsh is now a research associate at the University of Calgary. She continues to work on Newton’s methodology, both from a historical perspective and also relating this work to current debates in the philosophy of science.

Early modern experimental philosophy continues to be a research interest for all of us – we still have heaps to study and to blog about – so we will continue to contribute to this blog, along with the occasional guest-blogger. But in July we will start mostly to blog monthly instead of fortnightly. We value your interest in our blog, and we hope you will continue reading, commenting and criticising our research. Our posts will appear on the first Monday of every month.

We at Early Modern Experimental Philosophy thank you for your continued interest in our project.

Teaching Experimental Philosophy V: the case of James Bradley

Peter Anstey writes …

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

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

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

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

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