Borrowed Terms and Innovative Concepts in Newton’s Natural Philosophy
Kirsten Walsh writes…
In my last two posts, I have discussed my alterations to the 20 theses of our project. In this post, I’ll continue to discuss thesis 8.
In 2011, I claimed that:
- 8. The development of Newton’s method from 1672 to 1687 appears to display a shift in emphasis from experiment to mathematics.
But at the start of this year, I replaced this thesis with a new thesis 8:
- 8. In his early work, Newton’s use of the terms ‘hypothesis’ and ‘query’ are Baconian. However, as Newton’s distinctive methodology develops, these terms take on different meanings.
In my last post, I told you that I decided to remove my original thesis 8 because the methodological differences between Newton’s early papers and Principia aren’t as great as I initially thought. This isn’t to say that I now think that the methodology of the 1672 paper is precisely the same as the methodology displayed in Principia. Rather, I don’t think my original thesis 8 captures what is important about these differences.
In today’s post, I’ll tell you about my new thesis 8.
On this blog, we have argued that the early members of the Royal Society adopted the new experimental philosophy in a Baconian form. Newton initially encountered the experimental philosophy in the early- to mid-1660s through his reading of Boyle, Hooke and the Philosophical Transactions. While he never adopted the Baconian method of natural history, other features of his early methodology resemble the Baconian approach. For example, in Newton’s 1672 paper and the debate that followed, his use of experiment and queries, and his anti-hypothetical stance, were recognised and accepted by the Baconian experimental philosophers. Moreover, his 1675 paper, in which he explored his hypothesis of the nature of light, was recognised by his contemporaries as an acceptable use of a hypothesis.
In Newton’s later work, however, hypotheses and queries look quite different.
Firstly, consider Newton’s Opticks. When the Opticks was published in 1704, it contained no hypotheses, and the introduction explicitly stated that:
- “My Design in this Book is not to explain the Properties of Light by Hypotheses, but to propose and prove them by Reason and Experiments.”
Book III ended with a series of queries, which provided directions for further research, in the style of Baconian queries. E.g.:
- “Query 2. Do not the Rays which differ in Refrangibility differ also in Flexibility…?”
However, in the 1706 and 1718 editions, Newton introduced new queries, which explore the nature of light. E.g.:
- “Qu. 29. Are not the Rays of Light very small Bodies emitted from shining Substances?”
Like the earlier queries, these ones set out a new research program. But they are much more speculative than was acceptable according to the Baconian method.
Now consider Newton’s Principia. There are hypotheses in every edition of Principia, but they look nothing like Newton’s 1675 hypothesis. In particular, they do not explore the nature of things. For example:
- “Hypothesis 1. The centre of the system of the world is at rest.”
I have argued that the hypotheses in Principia provide a specific supportive role to theories. These propositions are temporarily assumed in order to draw out the observational consequences of Newton’s theory of gravitation. They are simplifying assumptions; not assumptions about the nature of gravity.
Previously, I have argued that Newton’s methodology should be seen as a three-way epistemic distinction between theories, hypotheses and queries. I call this an ‘epistemic triad’. I claim that Newton took these, already familiar, terms and massaged them to fit his own three-way epistemic distinction. It is important to recognise, therefore, that the triad is a three-way epistemic division, rather than the juxtaposition of three terms of reference. The terms ‘theory’, ‘hypothesis’ and ‘query’ are simply labels for these epistemic categories.
In fact, this is a feature of many of Newton’s innovative concepts. He borrowed familiar terms and massaged them to fit his own needs. I have shown that he did this with his key methodological terms: ‘theory’, ‘hypothesis’ and ‘query’. Steffen Ducheyne has argued that Newton did this in other aspects of his methodology, such as his dual-methods of analysis and synthesis. This suggests that Newton’s labeling and naming of things was very much post hoc. It seems that, when discussing Newton’s methodology, we should emphasize divisions and functions over definitions.
Defining early modern experimental philosophy (1)
Alberto Vanzo writes…
At the recent Bucharest conference on experiments in early modern philosophy, Mordechai Feingold warned against the attempt to characterize experimental philosophy in atemporal terms. The risk is losing sight of the different ways in which experimental philosophy was practised and understood in the course of time and ending up with a characterization which only applies to some experimental philosophers, or is too general to be helpful. To borrow an expression from Bas Van Fraassen’s book The Empirical Stance, Feingold (as I understood him) warned us not to claim that
- To be an (early modern) experimental philosopher = to believe that E+ (the experimentalist’s dogma).
I agree that being an early modern experimental philosopher did not simply amount to endorsing a certain philosophical claim. I tend to think of early modern experimental philosophy as a movement. We can identify the members of this movement based on at least three features which do not involve the commitment to specific philosophical claims:
1. Self-descriptions: experimental philosophers typically called themselves such. At the very least, they professed their sympathy towards experimental philosophy.
2. Friends and foes: experimental philosophers saw themselves as part of a tradition whose patriarch was Bacon, whose prominent members included Boyle, Locke, later Newton and Hume, and whose opponents were Aristotle and the Scholastics, later Descartes, even later (at least in some quarters) Leibniz.
3. Rhetoric: like the members of many movements, experimental philosophers endorsed a distinctive rhetoric. They praised experiments and observations and they criticized hypotheses and speculations (or certain uses and forms thereof). They called them fictions, romances, or castles in the air.
By conceiving of early modern experimental philosophy as a movement, we can accommodate Feingold’s invitation to take its evolution into account. The identity of movements can evolve in the course of time. This happened to experimental philosophy too. It broadened its scope from the study of nature and medicine to ethics and aesthetics (Hume, for instance, advocated the “application of experimental philosophy to moral subjects”). Its list of friends and foes were progressively extended. Its seventeenth-century members regarded the construction of Baconian natural histories as being central to the success of experimental philosophers. Its eighteenth-century exponents no longer took this to be an important or even useful endeavour.
However, experimental philosophers were also, crucially, committed to a certain method. This is why they placed so much emphasis on experiments and observations, while attacking hypotheses and speculations. They believed that the key to success in the study of the natural world (and, later, of ethics and aesthetics) was the endorsement of a method that involved reliance on experiments and observation and rejection of (certain forms of) hypotheses and speculations.
Of course, I am happy to grant that there were differences among the methods adopted by experimental philosophers. Newton’s method differed in several respects from those of Boyle and other experimental philosophers. However, it would be interesting if we could identify a specific methodological view that was shared by all or most experimental philosophers. To paraphrase Van Fraassen once again, it would interesting if we could state that
- To endorse the method of (early modern) experimental philosophy = to believe that E+ (the experimentalists’ methodical dogma).
But how should we define “E+”? Is there a single statement that we can identify “E+” with and that applies to all or most experimental philosophers? If so, then there still is an “atemporal” component of the commitment to experimental philosophy (in the early modern sense). Otherwise, we might be better off claiming, to quote again Van Fraassen, that the method of experimental philosophy is best seen as a “a stance (attitude, commitment, approach, a cluster of such […])” that, albeit related to belief in propositions like E+ (whatever that may be), will involve “a good deal more, will not be identifiable through the beliefs involved, and can persist through changes of belief”.
What should we identify E+, the the experimentalists’ methodical dogma, with? I will address this question in my next post. In the meanwhile, I would love to hear your thoughts and suggestions. Please leave a comment or send me an email.
Newton on Experiment and Mathematics
Kirsten Walsh writes…
In my last post, I discussed our 20 revised theses and why I altered thesis 5. In this post, I’ll discuss why I replaced thesis 8.
In 2011, I claimed that:
- 8. The development of Newton’s method from 1672 to 1687 appears to display a shift in emphasis from experiment to mathematics.
But at the start of this year, I replaced this thesis with a new thesis 8:
- 8. In his early work, Newton’s use of the terms ‘hypothesis’ and ‘query’ are Baconian. However, as Newton’s distinctive methodology develops, these terms take on different meanings.
Since my new thesis is a replacement of the original thesis, rather than a modification, two explanations are required. So in today’s post, I’ll tell you why I decided to remove my original thesis 8, and in my next post, I’ll tell you about my new thesis 8.
I originally included thesis 8 because there are some obvious differences in the styles of Newton’s early work on optics and his Principia. In Newton’s first paper on optics (1672), there is a strong emphasis on experiment. Experiment drives his research and guides his rejection of various possible explanations of the phenomena under consideration. Ultimately, he presents an Experimentum Crucis as proof for the certainty of his proposition that white light is heterogeneous. In contrast, the Principia (1687) displays a strong emphasis on mathematics. The full title of the work, the Author’s Preface to the Reader, and the fact that Book I opens with 11 lemmas outlining the mathematical framework of the work are just a few features that make it clear that Principia is primarily a mathematical treatise.
I now think that my original thesis 8 is misleading.
Firstly, as I have emphasised on this blog, Newton’s early work had a mathematical style that made it unique among his contemporaries. While they recognised him as an experimental philosopher, his claims of obtaining certainty via geometrical proofs set him apart from the Baconian-experimental philosophers. Moreover, his methodological statements show evidence of a tension between experiment and mathematical certainty. For example, he says that the science of colours,
- “depend[s] as well on Physicall Principles as on Mathematicall Demonstrations: And the absolute certainty of a Science cannot exceed the certainty of its Principles. Now the evidence by wch I asserted the Propositions of colours is in the next words expressed to be from Experiments & so but Physicall: Whence the Propositions themselves can be esteemed no more then Physicall Principles of a Science.”
Secondly, Newton continued to identify as an experimental philosopher until the end of his life. For example, in the General Scholium at the end of Principia, he says:
- “and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy.”
This resembles Newton’s earlier emphasis on grounding propositions on empirical evidence, rather than on speculative conjectures.
Thirdly, in Principia, Newton appears to be negotiating a similar tension between experiment and mathematical certainty that we saw in his early work. For example, in the Scholium to the Laws of Motion he asserts the certainty of his Laws, while at the same time, acknowledging their experimental basis:
- “The principles I have set forth are accepted by mathematicians and confirmed by experiments of many kinds.”
And:
- “By these examples [i.e. the experiments mentioned above] I wished only to show the wide range and the certainty of the third law of motion.”
From these three points, we can see that the methodological differences between Newton’s early papers and Principia aren’t as great as they first appear. But I did not remove my original thesis 8 because I think that the methodology of the 1672 paper is precisely the same as the methodology displayed in Principia. Rather, I don’t think my original thesis 8 captures what is important about these differences.
As I have explained here, my project is to distinguish between those features of Newton’s methodology that changed, and those that stayed the same. Some aspects of Newton’s methodology developed over time. For example, he came to value geometrical synthesis over algebraic analysis. Other aspects of his methodology varied according to context. For example, in Opticks, he employs ‘experiments’ and ‘observations’, but in Principia, he employs ‘phenomena’. But this triumvirate of methodological ideas – experiment, mathematics and certainty – should be considered an enduring feature of Newton’s methodology.
Geminiano Montanari on Natural History and Explanations
Alberto Vanzo writes…
A while ago, I wrote a post on the late seventeenth-century Italian natural philosopher, Geminiano Montanari. I argued that his stints of speculative reasoning were, after all, compatible with his allegiance to the experimental philosophy. In this post, I will focus on another aspect of Montanari’s experimentalism that appears to clash with his natural-philosophical practice: his view that, before even attempting to explain natural phenomena, we should compile a universal natural history.
The problem: disagreements and errors in natural philosophy
Montanari sees the compilation of a universal natural history as way of overcoming disagreements among philosophers. Having noted the many competing views on what “the first principles of natural things” may be, Montanari explains that this variety is due to the excessive self-confidence of “nearly all great minds”. Instead of jumping to first principles,
- It was necessary to start philosophy from particular things, examining the whole of nature one piece after another, and to amass a rich capital of experiences so as to prepare the historical matter on whose basis one should later speculate about the reasons [of those experiences].
The solution: building a universal natural history
We can avoid errors and reach agreement on the principles of things by following Francis Bacon’s suggestion of building a natural history including “all experiences and other certain information that one could get from faithful sources”.
How much information should be gathered before we can discover the first principles of natural things?
- [I]n order to find what the true, first and most universal principles of all things may be, it is not sufficient to make an induction from few terms, but it is necessary first to cognize all natural effects, so that one can later find a common reason which satisfies all experiences. But who can already boast to possess such an universal information?
Montanari’s answer is: nobody. It is still too early to make an induction from the observation of everything to its first cause. We must postpone the task of explaining the whole of nature and focus our strengths on the task of compiling natural histories.
Did Montanari do what he says?
He certainly collected many experiments and observations on manifold phenomena, from the capillary behaviour of liquids to the comets and celestial bodies. But he did not refrain from developing explanations of those phenomena, even though he was aware that his experiences were limited and many phenomena had not yet been observed. It is tempting to conclude that Montanari did not do what he says, that his allegiance to the Baconian view that a comprehensive data collection must precede natural-philosophical explanations was merely verbal, and that he was merely paying lip-service to the Baconian fashion of the time.
I do not think that this is the case. Montanari claims that completing a universal natural history is necessary to establish the “true, first and most universal principles of all things”. However, he does not claim that completing a universal natural history is necessary to explain specific natural phenomena, nor does he think that we must first establish the first principles of all things in order to explain specific phenomena. On the contrary, Montanari thinks that, upon completing a universal natural history, we will have to to advance piecemeal toward the first principles, by formulating explanations of specific phenomena and proceeding to increasingly higher levels of generality.
Montanari’s two-part discussions of specific phenomena follow, on a small scale, his favoured Baconian method that for establishing first principles. Regardless of whether he is discussing the capillary action, the behaviour of hot spheres of glass in water, or the position of a comet, Montanari starts by providing a natural history of the phenomenon at hand in the form of a list of observations and experiments. He then proceeds from the “historical matter” to its “reasons”, that is, he provides natural-philosophical explanations of the phenomena.
These explanations are fallible. Natural histories are inescapably incomplete and it is always possible that future experiments or observations invalidate his explanations. However, Montanari holds that it is possible to “deduce” explanations “with physico-mathematical evidence” from a suitable, even if limited, natural-historical basis. What warrants his explanations is the fact that they “explain all the other effects we have observed.”
In conclusion, Montanari does not violate his claim that we should build a universal natural history before identifying the very first principles of the whole nature. The magnitude of the task suggests that this may be only a regulative ideal and may even warrant a certain scepticism on whether we will ever be able to discover the first principles. However, discovering these principles is not necessary to do science for Montanari. What drives Montanari’s natural philosophy is the fact that he allows for fallible natural-philosophical explanations which are based on small-scale, necessarily incomplete, subject-specific natural histories.
Newton and the ESD
Kirsten Walsh writes…
We rang in 2013 by reconsidering our set of 20 core theses on the emergence and fate of early modern experimental philosophy. While our general theses regarding the distinction between experimental and speculative philosophy (ESD) were unchanged, I altered several of the specific claims about Newton’s methodology. In this post, I’ll focus on thesis 5 and why I changed it.
In 2011, I claimed that:
5. The ESD is operative in Newton’s early optical papers.
By ‘operative’, I mean that Newton appears to frame his methodology in terms of the ESD and aligns himself with the experimental philosophers of the Royal Society. While Newton’s methodology differed from his contemporaries in important ways (for example, unlike his contemporaries, Newton emphasised quasi-mathematical reasoning), it nevertheless reflects some of the key ideas and preferences of the Royal Society. Previously, I have discussed Newton’s early anti-hypothetical stance and Newton’s early use of queries as evidence of this his preference for the experimental philosophy of the Royal Society.
I now have enough evidence to broaden the scope of thesis 5. The ESD is operative in all of Newton’s scientific work; not just his early work:
5. The ESD is operative in Newton’s work, from his early work on optics in the 1670s to the final editions of Opticks and Principia published in the 1720s.
Let’s start with Newton’s Opticks. This book is widely recognised as a work of experimental philosophy. Newton’s experimental focus is made explicit by the opening sentence (which appears in every edition):
- “My Design in this Book is not to explain the Properties of Light by Hypotheses, but to propose and prove them by Reason and Experiments…”
Moreover, the presence of queries and the absence of hypotheses reflect the epistemic commitments of the experimental philosophy.
Commentators often notice that, in later editions of Opticks, Newton’s queries become increasingly speculative. This suggests that, despite his use of ESD-jargon, Newton was not following the experimental philosophy after all. In response to this kind of objection, I have argued that these later queries perform a role that is distinct to that of hypotheses, and that this role is consistent with Newton’s methodology. Moreover, the general features of Newton’s methodology reflect his commitment to experimental philosophy in opposition to speculative philosophy. In short, the ESD is operative in every edition of the Opticks.
Now consider Newton’s Principia. This book is often seen as less a work of experimental philosophy and more a work of mathematics. However, I have argued that the methodological passages in the first edition of Principia, though sparse, make it clear that experiment is an important theme of this work. Moreover, in the ‘General Scholium’, which was introduced in the 2nd edition in 1713, Newton makes his commitment to the experimental philosophy explicit.
Commentators often notice that Newton’s use of hypotheses in Principia, and their changing roles between the three editions, suggest that his methodology changes over time. However, I have argued that, in all three editions, Newton’s use of hypotheses is consistent with his experimental method. Moreover, the late introduction of Rule 4 in 1726 demonstrates that this commitment to experimental philosophy, in opposition to speculative philosophy, is long-lasting. In short, the ESD is operative in every edition of the Principia.
To summarise, the notions of experiment, queries and a decrying of speculative hypotheses that are enduring themes in Newton’s work, from the 1670s to his death in 1727, support my broader thesis 5. Commentators often see Newton’s use of these notions as rhetorical and argue that he failed to follow his own methodology. However, I argue that Newton’s methodology is internally consistent. Moreover, these methodological statements are more than ‘mere’ rhetoric. Rather, to some extent they track his epistemic and ontological commitments.
Do you think my argument is convincing? I’d love to hear what you think about my conclusion.
Empiricism and innate ideas
Alberto Vanzo writes…
The empiricism/rationalism distinction (RED) is still often characterized, at least in part, in terms of the rejection or endorsement of innate ideas. Empiricists like Locke, Berkeley and Hume are said to deny that we have innate ideas, whereas rationalists are said to have endorsed innatism. Empiricists are also said to have rejected, and rationalists to have endorsed, substantive a priori truths. However, I will only focus on innate ideas in this post. Is it plausible to distinguish early modern empiricists from early modern rationalists on the basis of their attitude toward innate ideas? Here are five reasons to doubt that this is plausible.
1. Spinoza. As Luis Loeb noted, “Spinoza is completely silent on the subject of innateness”. He never claimed that we have innate ideas. However, he famously denied that mind and body interact. This may be taken to imply that our ideas, rather than deriving from sense experience, are innate.
2. Berkeley. In his most famous writings, Berkeley did not claim that all of our ideas have sensory origin, nor did he reject innate ideas. He only rejected abstract ideas. But the greatest difficulties for enrolling the “empiricist” Berkeley among the enemies of innatism come from his personal notes. Not only did he write that Locke was “tedious about innate ideas” (Luce/Jessop, 9:153), but he also wrote in his Notebooks (649) that “[t]here are innate ideas i.e. Ideas created with us.” (1, 2).
3. Malebranche. The “rationalist” Malebranche attacked, rather than endorsed, innate ideas. As Nicholas Jolley noted, Malebranche’s rejection of innatism derives from his anti-psychologism. Ideas, “according to Malebranche, are not in the mind at all; indeed, they are not the sort of entities which could be in a mind. So if there are, and could be, no ideas in a mind at any time, a fortiori there are no innate ideas.”
Descartes can reply that ideas are only innate in us in
- the same sense as that in which we say that generosity is “innate” in certain families, or that certain diseases such as gout or stones are innate in others: it is not so much that the babies of such families suffer from these diseases in their mother’s womb, but simply that they are born with a certain “faculty” or tendency to contract them. (Comments on a Certain Broadsheet)
Malebranche rebuts that this form of innatism is trivial and vacuous. Saying that our ideas are innate because our mind has the capacity to form or bring them to consciousness under appropriate circumstances is like saying that we fall asleep because we have a dormitive virtue. What we need to know are the categorical, non-dispositional properties that ground these dispositions.
4. Leibniz. Leibniz was aware of Malebranche’s criticism. When he defends the doctrine of innate ideas (most notably, in the New Essays), he is fighting a battle on two fronts. On the one hand, he counters Locke’s rejection of innatism in the first book of the Essay. On the other hand, he responds to Malebranche, because he too endorses the dispositional account of innate ideas attacked by Malebranche: “This is how ideas and truths are innate in us – as inclinations, dispositions, tendencies, or natural potentialities and not as actions”. So, the standard account of Leibniz’s innatism as a rationalist reply to Locke’s concept-empiricism is too simplistic. Leibniz is opposing the “rationalist” Malebranche as well as the “empiricist” Locke. (As Nicholas Jolley explains in The Light of the Soul, Leibniz replies to Malebranche by identifying the categorical basis of the relevant dispositions with unconscious petites perceptiones).
5. Boyle and the Cimento. Things become even more complicated if we consider less-known authors like Robert Boyle or the Italian natural philosophers who were associated with the Accademia del Cimento. They are usually regarded as empiricists. Yet Boyle mentions “inbred notions” or endorses innatism in various passages (e.g. The Christian Virtuoso, in The Works of Robert Boyle, eds. Hunter/Davis, 11:300-301). The opening of the Cimento’s Saggi di naturali esperienze mentions innate notizie that God has planted in our soul and that we recollect in the course of experience. Passages like these are hard to reconcile with the tendency to take the endorsement or rejection of innate ideas as a criterion to distinguish between early modern empiricists and rationalists.
I agree with Loeb that the empiricism/rationalism distinction is broken-backed. However, if one still wants to use it, one cannot appeal to the endorsement or rejection of innate ideas as scholars have often done. Do you think that this conclusion is convincing? I would love to hear your views in the comments.
CFP: Special issue on Early Modern Baconians
Early Modern Baconians: Science, Politics and Philosophy
This special issue of SOCIETY AND POLITICS aims to gather together articles dealing with the formation, evolution and influence of Francis Bacon’s thought. We are particularly interested in articles exploring the influence of Francis Bacon’s ideas upon seventeenth and eighteenth century European thought: from science to politics, and from religion to the evolution of literary forms and genres. Our purpose is to accommodate a diversity of approaches, coming from different fields. We welcome articles on experiment and experimental science, natural history, medicine of the mind, the Baconian ‘method’, the advancement of learning, religion and theology, politics and the reformation of law, fables and projects for ‘scientific’ or ‘esoteric’ societies (inspired by Francis Bacon’s writings). SOCIETY AND POLITICS welcomes research coming from different fields and strongly encourages cross-disciplinary approaches.
SOCIETY AND POLITICS is a peer-reviewed scholarly journal published by “Vasile Goldiș” Western University of Arad, Romania. Papers no longer than 8,000 words and book reviews no longer than 800 words should be submitted by email to Dana Jalobeanu and Oana Matei by the 10th of February 2013. Guidelines for authors here.
—
Dr Dana Jalobeanu
University of Bucharest
Faculty of Philosophy
Splaiul Independentei 204
Bucuresti
An Update…
Kirsten Walsh writes …
Hello, Readers!
As 2012 draws to a close, we’d like to announce some minor changes to our blog. While our Marsden funding has ended and we are gradually moving onto other new projects, our interest in early modern experimental philosophy continues and so will this blog.
Peter Anstey has moved to the University of Sydney, where he is about to begin a project on ‘The nature and status of principles in early modern philosophy’. His book John Locke and Natural Philosophy has recently been awarded the Journal of the History of Philosophy Book Prize for the best book on the history of Western philosophy published in 2011.
And Alberto Vanzo has moved to the University of Birmingham, where he is a Marie Curie research fellow. He is working on developments in the history of the rationalism and empiricism distinction.
We still have much to study and to blog about – so we will all continue to make regular posts on this blog, along with the occasional guest-blogger. But in the New Year, we will post fortnightly instead of weekly. We value your interest in our blog, and we hope you will continue reading, commenting and criticizing and contributing to our research next year. Our first post of 2013 will appear on 7 January.
We at Early Modern Experimental Philosophy wish you a happy festive season and look forward to hearing from you in 2013!
On a final note, since tomorrow marks 370 years since Newton was born*, I couldn’t resist adding this picture. My apologies to those of you with historically-sensitive eyes!
*Actually, Newton was born on 25 December 1642 on the Julian (‘Old Style’) calendar, which adjusts to 4 January 1643 on the Gregorian (‘New Style’) calendar.
Did Newton Adopt Hypothetico-Deductivism?
Kirsten Walsh writes…
In 1718, Newton published the second edition of Opticks. Query 23 was renamed Query 31, and in this query Newton expanded on his method of analysis. He wrote:
- “If no Exception occur from Phænomena, the Conclusion may be pronounced generally. But if at any time afterwards any Exception shall occur from Experiments, it may then begin to be pronounced with such Exceptions as occur.”
At first glance, this passage suggests that Newton adopted the hypothetico-deductive method, in that the epistemic status of a theory is sensitive to new evidence. However, if we consider how Newton put this methodology into practice, in Principia book III, we will get a different reading of this passage.
In the 3rd edition of Principia, Newton introduced a 4th rule of philosophising:
- “In experimental philosophy, propositions gathered from phenomena by induction should be considered either exactly or very nearly true notwithstanding any contrary hypotheses, until yet other phenomena make such propositions either more exact or liable to exceptions.”
The similarities between this rule and the earlier passage from Query 31 are striking: that new evidence can make a proposition “either more exact or liable to exceptions” is similar to pronouncing the conclusion either “more generally” or “with such Exceptions as occur”. So looking at how this rule was employed should tell us a lot about how to interpret the earlier passage.
In Principia, Newton only explicitly employed rule 4 once: in proposition 5 book III. In this proposition, Newton made his argument for universal gravitation by generalising step-by-step from the motions of the planets around the sun, and the satellites of Saturn and Jupiter around their respective centres, to the forces producing those motions. Newton introduced three corollaries, the third of which states that “all planets gravitate towards one another”.
In the scholium following this corollary, Newton said:
- “Hitherto we have called ‘centripetal’ that force by which celestial bodies are kept in their orbits. It is now established that this force is gravity, and therefore we shall call it gravity from now on. For the cause of the centripetal force by which the moon is kept in its orbit ought to be extended to all the planets, by rules 1, 2, and 4.”
Rules 1 and 2 tell us not to postulate more causes than necessary, and that we should assume that effects of the same kind have causes of the same kind. In this context, rule 4 tells us that, if exceptions to universal gravitation occur, then instead of reducing our credence in the theory, we should reduce the scope of the theory: it is still true, but true of less instances. De-generalising a theory doesn’t reduce its certainty; rather, it reduces the scope of the theory while maintaining its certainty. So according to rule 4:
- In the absence of exceptions, we should take gravity to be universal.
- If exceptions to universal gravitation are found, we should infer that the domain of gravity is limited (i.e. not universal).
- We should not allow our assumptions about matter theory (e.g. the improbability of action at a distance) to have any influence on our epistemic attitude towards universal gravitation.
Instead of reading rule 4 and the passage from Query 31 as accounts of hypothetico-deductivism, we should read them as accounts of what I Bernard Cohen called the ‘Newtonian Style’: a way of modelling the world in a series of increasingly complex and increasingly accurate idealisations (i.e. approximations that would hold exactly in certain specifiable circumstances).
On this blog, I have often discussed Newton’s aim of certainty and his corresponding claims to have achieved this aim. Newton’s youthful aim of certainty places him in a position that is quite isolated from his contemporaries. Most of the experimental philosophers of the Royal Society thought it epistemically irresponsible to make such bold claims. Instead, they had more modest aims: obtaining highly probable theories. Rule 4, and the passage from Query 31, suggest that Newton eventually adopted a version of the hypothetico-deductivism preferred by his contemporaries. I have argued, however, that this is a misleading way of reading these passages. Newton uses rule 4, not to update the epistemic warrant of the theory, but its scope.
CFP: Aristotelian Natural Philosophy in the Early Modern Period
From Lucian Petrescu:
The Sarton Centre for History of Science and the Department of Philosophy and Moral Science, Ghent University announces a conference on
23-24 May 2013
with the theme
Aristotelian natural philosophy in the early modern period
Early modern philosophers liked to debate about Aristotle just as much as medieval scholars. They had different sources to fuel their discussions: from the humanist preoccupation with a pristine Aristotle and a purification of a corpus perceived as corrupted to the very medieval doctors that others sought to forget. This conference aims at reconstructing the various ways in which Aristotle’s natural philosophical books were read and used to nourish various philosophical agendas.
We welcome papers on any topic related to late medieval and early modern natural philosophy (roughly 1300-1700) that can contribute to a better understanding of the reception of Aristotle in the period. Papers focussing on the reception of less prominent books of the /corpus aristotelicum/, such as the /Meteorologica/ or the /Parva Naturalia/, are especially welcome.
For paper submissions, please send an abstract of 500 words by *January 15th*, in English or French, to Lucian Petrescu <lucian.petrescu@ugent.be> and Maarten van Dyck <maarten.vandyck@ugent.be>.
Invited speakers: Daniel Andersson (Oxford University / Babes-Bolyai University Cluj), Roger Ariew (University of South Florida), Paul Richard Blum (Loyola University Maryland), Helen Hattab (University of Houston), Carla Rita Palmerino (Radboud University Nijmegen).
Contact: Lucian Petrescu and Maarten Van Dyck.
