Posts Tagged ‘natural philosophy’
Monday, July 22nd, 2013 | Comments Off
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.
Thursday, November 29th, 2012 | Comments Off
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 <firstname.lastname@example.org> and Maarten van Dyck <email@example.com>.
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.
Monday, August 6th, 2012 | Comments Off
Kirsten Walsh writes…
During the debate following the publication of Newton’s first paper, Newton provided a set of eight queries, in an attempt to steer the debate towards a satisfactory conclusion. When Henry Oldenburg, Secretary of the Royal Society and Editor of the Philosophical Transactions, published Newton’s queries, he added the following introduction:
- A Serie’s of Quere’s propounded by Mr. Isaac Newton, to be determin’d by Experiments, positively and directly concluding his new Theory of Light and Colours; and here recommended to the Industry of the Lovers of Experimental Philosophy, as they were generously imparted to the Publisher in a Letter of the said Mr. Newtons of July 8. 1672.
However, Newton didn’t describe his own work as ‘experimental philosophy’ until 1713, when he added the General Scholium to the Principia. He wrote:
- … and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy. In this experimental philosophy, propositions are deduced from the phenomena and are made general by induction.
In 1672, would Newton have been comfortable with Oldenburg’s label ‘experimental philosopher’? Or did he consciously avoid the label, as Alan Shapiro suggests, in order to distance himself from the methodology of the early Royal Society?
Oldenburg on ‘Experimental Philosophy’
To begin, what did Oldenburg mean by ‘experimental philosophy’? Let’s look at his prefaces to each issue of the Philosophical Transactions.
Firstly, Oldenburg was talking about the Baconian experimental philosophy. In the 1672 Preface, Oldenburg chose to adopt Bacon’s term, ‘Operative Philosophy’, which he used interchangeably with the term ‘Experimental Philosophy’. And he wrote:
- But, when our renowned Lord Bacon had demonstrated the Methods for a perfect Restauration of all parts of Real knowledge … The success became on a sudden stupendious, and Effective philosophy began to sparkle, and even to flow into beams of bright-shining Light, all over the World.
Moreover, in 1671, Oldenburg advocated Abraham Cowley’s Baconian-vision for the Royal Society. In his book, Proposition for the Advancement of Experimental Philosophy, Cowley proposed that the Royal Society appoint professors who were:
- bound to study and teach all sorts of Natural, Experimental Philosophy, to consist of the Mathematicks, Mechanicks, Medicine, Anatomy, Chymistry, the History of Animals, Plants …. and briefly all things contained in the Catalogue of Natural Histories annexed to My Lord Bacon’s Organon.
(Incidentally, in a previous post on this blog, Peter Anstey has identified this as the first English book to use the term ‘experimental philosophy’ in its title.)
Secondly, Oldenburg had in mind an experimental philosophy that emphasised the construction of natural histories. For example, in 1669, Oldenburg wrote:
- …we then made an Attempt of laying some Foundation for the Improvement of real Philosophy, and for the spreading of Useful knowledge; in publishing Advices and Directions for the writing of an Experimental Natural History…
Thirdly, Oldenburg had in mind an experimental philosophy that attempted to recover ancient knowledge. For example, in 1671, responding to critics of the experimental philosophy, Oldenburg wrote:
- they call it contemptuously the New Philosophy; when as yet perhaps themselves are not ignorant, that ‘tis so old as to have been the Discipline in Paradise; and from the First of Mankind … to have been practised and countenanced by the Best of Men…
- … we may not lay aside the other expedient, which is so helpful to explicate the Old Wonders of Art, and Old Histories of Nature; namely, To inquire diligently The things that are; What Rarities of Nature, and what Inventions of Men are now extant in any parts of the World.
To summarise, Oldenburg had in mind an experimental philosophy that:
- Followed Bacon’s method;
- Constructed natural histories; and
- Investigated ancient knowledge.
Newton on ‘Experimental Philosophy’
Would Newton have approved of this way of describing his work?
Certainly Newton would have approved of being broadly aligned with the experimentalist philosophers, as opposed to the speculative philosophers. In his ‘Queries Paper’, he wrote:
- … the Theory … was evinced to me … not by deducing it only from a confutation of contrary suppositions, but by deriving it from Experiments concluding positively and directly.
And in the first paper, he wrote: “And I shall not mingle conjectures with certainties”.
While Newton didn’t construct natural histories, he may have approved of the Baconian overtones of the label. For, as I’ve discussed previously, Newton’s 1672 queries resemble Baconian queries.
Newton may even have approved of the suggestion that his method had ties to the Ancients. For example, as early as 1686, in his Preface to Principia, Newton emphasised the influence of the Ancients:
- Since the Ancients (according to Pappus) considered mechanics to be of the greatest importance in the investigation of nature and science and since the moderns – rejecting substantial forms and occult qualities – have undertaken to reduce the phenomena of nature of mathematical laws, it has seemed best in this treatise to concentrate on mathematics as it relates to natural philosophy.
So, I think Newton would have approved of Oldenburg’s label, even though later on, when he came to describe his own experimental philosophy, the emphasis was quite different. For example, in Query 31 of the Opticks, Newton wrote:
- This Analysis consists in making Experiments and Observations, and in drawing general Conclusions from them by Induction, and admitting of no Objections against the Conclusions, but such as are taken from Experiments, or other certain Truths. For Hypotheses are not to be regarded in experimental Philosophy.
Monday, July 18th, 2011 | Comments Off
Kirsten Walsh writes…
In book three of the 3rd edition of Principia, Newton added a fourth rule for the study of natural philosophy:
- 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.
- This rule should be followed so that arguments based on induction be not be nullified by hypotheses.
Arguably this is the most important of Newton’s four rules, and it certainly sparked a lot of discussion at our departmental seminar last week. Let us see what insights we can glean from it.
Rule 4 breaks down neatly into three parts. I shall address each part in turn.
1. Propositions (acquired from the phenomena by induction) should be regarded as true or very nearly true.
While the term ‘phenomenon’ usually refers to a single occurrence or fact, Newton uses the term to refer to a generalisation from observed physical properties. For example, Phenomenon 1, Book 3:
- The circumjovial planets [or satellites of Jupiter], 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.
- This is established from astronomical observations…
Newton uses the term ‘proposition’ in a mathematical sense to mean a formal statement of a theorem or an operation to be completed. Thus, he further identifies propositions as either theorems or problems. Propositions are distinguished from axioms in that propositions are not self-evident. Rather, they are deduced from phenomena (with the help of definitions and axioms) and are demonstrated by experiment. For example, Proposition 1, Theorem 1, Book 3:
- The forces by which the circumjovial planets [or satellites of Jupiter] 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.
- The first part of the proposition is evident from phen. 1 and from prop. 2 or prop. 3 of book 1, and the second part from phen. 1 and from corol. 6 to prop. 4 of book 1.
Newton appears to be using ‘induction’ in a very loose sense to mean any kind of argument that goes beyond what is stated in the premises. As I noted above, his phenomena are generalisations from a limited number of observed cases, so his natural philosophical reasoning is inductive from the bottom up. Newton recognises that this necessary inductive step introduces the same uncertainty that accompanies any inductive generalisation: the possibility that there is a refuting instance that hasn’t been observed yet.
Despite this necessary uncertainty, in the absence of refuting instances, Newton tells us to regard these propositions as true or very nearly true. It is important to note that he is not telling us that these propositions are true, simply that we should act as though they are. Newton is simply saying that if our best theory fits the available data, then we should regard it as true until proven otherwise.
2. Hypotheses cannot refute or alter those propositions.
In a previous post I argued that, in his early optical papers, Newton was working with a clear distinction between theory and hypothesis. In Principia Newton is working with a similar distinction between propositions and hypotheses. Propositions make claims about observable, measurable physical properties, whereas hypotheses make claims about unobservable, unmeasurable causes or natures of things. Thus, propositions are on epistemically surer footing than hypotheses, because they are grounded on what we can directly experience. When faced with a disagreement between a hypothesis and a proposition, we should modify the hypothesis to fit the proposition, and not vice versa. Newton explains this idea in a letter to Cotes:
- But to admitt of such Hypotheses in opposition to rational Propositions founded upon Phaenomena by Induction is to destroy all arguments taken from Phaenomena by Induction & all Principles founded upon such arguments.
3. New phenomena may refute those propositions by contradicting them, or alter those propositions by making them more precise.
This final point highlights the a posteriori justification of Newton’s theories. In Principia, two methods of testing can be seen. The first involves straightforward prediction-testing. The second is a more sophisticated method, which involves accounting for discrepancies between ideal and actual motions by a series of steps that increase the complexity of the model.
In short, Rule 4 tells us to prioritise propositions over hypotheses, and experiment over speculation. These are familiar and enduring themes in Newton’s work, which reflect his commitment to experimental philosophy. Rule 4 echoes the remarks made by Newton in a letter to Oldenburg almost 54 years earlier, when he wrote:
- …I could wish all objections were suspended, taken from Hypotheses or any other Heads then these two; Of showing the insufficiency of experiments to determin these Queries or prove any other parts of my Theory, by assigning the flaws & defects in my Conclusions drawn from them; Or of producing other Experiments wch directly contradict me…