Kirsten Walsh writes…
Lately I have been examining Baconian interpretations of Newton’s Principia. First, I demonstrated that Newton’s Moon test resembles a Baconian crucial instance. And then, I demonstrated that Newton’s argument for universal gravitation resembles Bacon’s method of gradual induction. This drew our attention to some interesting features of Newton’s approach, bringing the Principia’s experimental aspects into sharper focus. But they also highlighted a worry: Newton’s methodology resembling Bacon’s isn’t enough to establish that Newton was influenced by Bacon. Bacon and Newton were gifted methodologists—they could have arrived independently at the same approach. One way to distinguish between convergence and influence is to see if there’s anything uniquely or distinctively Baconian in Newton’s use of crucial experiments and gradual induction. Another way would be if we could find some explicit references to Bacon in relation to these methodological tools. Alas, so far, my search in these areas has produced nothing.
In this post, I’ll consider an alternative way of understanding Baconianism in the Principia. I began this series by asking whether we should regard Newton’s methodology as an extension of the Baconian experimental method, or as something more unique. In answering, I have hunted for evidence that the Principia is Baconian insofar as Newton applied Baconian methodological tools in the Principia. But you might think that whether Newton was influenced by Bacon isn’t so relevant. Rather, what matters is how the Principia was received by Newton’s contemporaries. So in this post, I’ll examine Mary Domski’s argument that the Principia is part of the Baconian tradition because it was recognised, and responded to, as such by members of the Royal Society.
Domski begins by dispelling the idea that there was no place for mathematics in the Baconian experimental tradition. Historically, Bacon’s natural philosophical program, centred on observation, experiment and natural history, was taken as fundamentally incompatible with a mathematical approach to natural philosophy. And Bacon is often taken to be deeply distrustful of mathematics. Domski argues, however, that Bacon’s views on mathematics are both subtler and more positive. Indeed, although Bacon had misgivings about how mathematics could guide experimental practice, he gave it an important role in natural philosophy. In particular, mathematics can advance our knowledge of nature by revealing causal processes. However, he cautioned, it must be used appropriately. To avoid distorting the evidence gained via observation and experiment, one must first establish a solid foundation via natural history, and only then employ mathematical tools. In short, Bacon insisted that the mathematical treatment of nature must be grounded on, and informed by, the findings of natural history.
Domski’s second move is to argue that seventeenth-century Baconians such as Boyle, Sprat and Locke understood and accepted this mathematical aspect of Bacon’s methodology. Bacon’s influence in the seventeenth century was not limited to his method of natural history, and Baconian experimental philosophers didn’t dismiss speculative approaches outright. Rather, they emphasised that there was a proper order of investigation: metaphysical and mathematical speculation must be informed by observation and experiment. In other words, there is a place for speculative philosophy after the experimental stage has been completed.
Domski then examines the reception of Newton’s Principia by members of the Royal Society—focusing on Locke. For Locke, natural history was a necessary component of natural philosophy. And yet, Locke embraced the Principia as a successful application of mathematics to natural philosophy. Domski suggests that we read Locke’s Newton as a ‘speculative naturalist’ who employed mathematics in his search for natural causes. She writes:
[O]n Locke’s reading, Newton used a principle—the fundamental truth of universal gravitation—that was initially ‘drawn from matter’ and then, with evidence firmly in hand, he extended this principle to a wide store of phenomena. By staying mindful of the proper experimental and evidentiary roots of natural philosophy, Newton thus succeeded in producing the very sort of profit that Sprat and Boyle anticipated a proper ‘speculative’ method could generate (p. 165).
In short, Locke regarded Newton’s mathematical inference as the speculative step in the Baconian program. That is, building on a solid foundation of observation and experiment, Newton was employing mathematics to reveal forces and causes.
In summary, Domski makes a good case for viewing the mathematico-experimental method employed in the Principia as part of the seventeenth-century Baconian tradition. I have a few reservations with her argument. For one thing, ‘speculative naturalist’ is surely a term that neither Locke nor Newton would have been comfortable with. And for another thing, although Domski has provided reasons to view Newton’s mathematico-experimental method as related to, and a development of, the experimental philosophy of the Royal Society, I’m not convinced that this shows that they viewed the Principia as Baconian. That is to say, there’s a difference between being part of the experimental tradition founded by Bacon, and being Baconian. I’ll discuss these issues in my next post, and for now, I’ll conclude by discussing some important lessons that I think arise from Domski’s position.
Firstly, we can identify divergences between Newton and the Baconian experimental philosophers. And these could be surprising. It’s not, in itself, his use mathematics and generalisations that makes Newton different—Domski has shown that even the hard-out Baconians could get on board with these features of the Principia. The differences are subtler. For example, as I’ve discussed in a previous post, Boyle, Sprat and Locke advocated a two-stage approach to natural philosophy, in which construction of natural histories precedes theory construction. But Newton appeared to reject this two-stage approach. Indeed, in the Principia, we find that Newton commences theory-building before his knowledge of the facts was complete.
Secondly, the account highlights the fact that early modern experimental philosophy was a work in progress. There was much variation in its practice, and room for improvement and evolution. Moreover, its modification and development was, to a large extent, the result of technological innovation and the scientific success of works like the Principia. Indeed, it was arguably the ability to recognise and incorporate such achievements that allowed experimental philosophy to become increasingly dominant, sophisticated and successful in the eighteenth century.
Thirdly, the account suggests that, already in the late-seventeenth century, the ESD framework was being employed to guide, and also to distort, the interpretation and uptake of natural philosophy. By embracing the Principia as their own, the early modern experimental philosophers intervened on and shaped its reception, and hence, the kind of influence the Principia had. This raises an interesting point about influence.
As I have already noted, it is difficult to establish a direct line of influence stretching from Bacon to Newton. But, by focusing on how Bacon’s program for natural philosophy was developed by figures such as Boyle, Sprat and Locke, we can identify a connection between Bacon’s natural philosophical program and Newton’s mathematico-experimental methodology. That is, we can distinguish between influence in terms of actual causal connections—Newton having read Bacon, for instance—and influence insofar as some aspect of Newton’s work is taken to be related to Bacon’s by contemporary (or near-contemporary) thinkers. Indeed, Newton could have been utterly ignorant of Bacon’s actual views on method, but the Principia might nonetheless deserve to be placed alongside Bacon’s work in the development of experimental philosophy. Sometimes what others take you to have done is more important than what you have actually done!
Peter Anstey writes…
It is not uncommon for very minor contributors to early modern thought to go unnoticed, but every now and then they turn out to be worth investigating. One such person is Robert Saint Clair. A Google search will not turn up much on Saint Clair, and yet he was a servant of Robert Boyle and a signatory to and named in Boyle’s will. He promised twice to supply the philosopher John Locke with some of Boyle’s mysterious ‘red earth’ after his master’s death, and a letter from Saint Clair to Robert Hooke was published in the Philosophical Transactions of the Royal Society (vol. 20, 1698, pp. 378–81).
What makes Saint Clair interesting for our purposes is his book entitled The Abyssinian Philosophy Confuted which appeared in 1697. For in that book, which contains his own translation of Bernardino Ramazzini’s treatise on the waters of Modena, Saint Clair attacks Thomas Burnet’s highly speculative theory of the formation of the earth. I quote from the epistle to the reader:
I shall not care for the displeasure of these men of Ephesus [Burnet and others], whose trade it is to make Shrines to this their Diana of Hypothetical Philosophy, I mean who in their Closets make Systems of the World, prescribe Laws of Nature, without ever consulting her by Observation and Experience, who (to use the Noble Lord Verulams words) like the Spider … spin a curious Cob-web out of their Brains … (sig. a4)
The rhetoric of experimental philosophy could hardly be more obvious. Burnet and the other ‘world-makers’ are criticized for being adherents of ‘Hypothetical Philosophy’, for making ‘Systems of the World’, and for not consulting nature by ‘Observation and Experience’. He also praises Ramazzini’s work for being ‘the most admirable piece of Natural History’ (sig. a2). Saint Clair rounds off this passage with a reference to Bacon’s famous aphorism (about which we have commented before) from the New Organon comparing the spider, the ant and the bee to current day natural philosophers (I. 95).
What can we glean from Saint Clair’s critique here? First, it provides yet another piece evidence of the ubiquity of the ESD in late seventeenth-century England: the terms of reference by which Saint Clair evaluated Burnet were clearly those of experimental versus speculative philosophy.
Second, it is worth noting the term ‘Hypothetical Philosophy’. This expression was clearly ‘in the air’ in the late 1690s in England. For instance, it is found in John Sergeant’s Solid Philosophy Asserted which was also published in 1697. Indeed, it is the very term that Newton used in a draft of his letter of 28 March 1713 to Roger Cotes to describe Leibniz and Descartes years later. Clearly the term was in use as a pejorative before Newton’s attack on Leibniz.
Saint Clair has been almost invisible to early modern scholarship on English natural philosophy and yet his case is a nice example of the value of inquiring into the plethora of minor figures surrounding those canonical thinkers who still capture most of our attention. I would be grateful for suggestions as to names of others whom I might explore.
Incidentally, Saint Clair obviously thought that John Locke might be interested in his book, for we know from Locke’s Journal that he sent him a copy.
Peter Anstey writes…
The Cartesian vortex theory of planetary motions came under serious suspicion in England in the early 1680s. To be sure, many still spoke of ‘our vortex’ well into the 1680s and ’90s, such as Robert Boyle in his Notion of Nature of 1686 (Works, eds. Hunter and Davis, London, 1999–2000, 10, p. 508), but by the early 1690s the new Newtonian cosmology was coming to be widely accepted and many in England thought that the vortex theory had been disproved. By that time the vortex theory of planetary motions had come to be seen as the archetypal form of speculative natural philosophy. What was required then was a new descriptor for that cosmological structure in which the earth is located. And a new term was soon deployed, namely, ‘solar system’.
Some have claimed that it was John Locke who coined the term ‘solar system’. In fact, the OED lists Locke’s Elements of Natural Philosophy, which it dates at c.1704, as the earliest occurrence. However, the term first appears in his writings in Some Thoughts concerning Education of 1693 where speaking of Newton’s ‘admirable Book’ about ‘this our Planetary World’, he says,
his Book will deserve to be read, and give no small light and pleasure to those, who willing to understand the Motions, Properties, and Operations of the great Masses of Matter, in this our Solar System, will but carefully mind his Conclusions… (Clarendon edition, 1989, p. 249)
Interestingly, a quick word search of EEBO reveals that the term was also used by Richard Bentley in his seventh Boyle lecture of 7 November 1692, but published in 1693 in a volume that Locke owned (Folly & Unreasonableness of Atheism, London). Bentley uses the term in an argument for the existence of God on the basis of the claim that the fixed stars all have the power of gravity. It is God who prevents the whole system from collapsing into a common centre:
here’s an innumerable multitude of Fixt Starrs or Suns; all of which are demonstrated (and supposed also by our Adversaries) to have Mutual Attraction: or if they have not; even Not to have it is an equal Proof of a Divine Being, that hath so arbitrarily indued Matter with a Power of Gravity not essential to it, and hath confined its action to the Matter of its own Solar System: I say, all the Fixt Starrs have a principle of mutual Gravitation; and yet they are neither revolved about a common Center, nor have any Transverse Impulse nor any thing else to restrain them from approaching toward each other, as their Gravitating Powers incite them. Now what Natural Cause can overcome Nature it self? What is it that holds and keeps them in fixed Stations and Intervals against an incessant and inherent Tendency to desert them? (p. 37, underlining added)
There is no evidence, however, that Bentley was using the term as an alternative to ‘our vortex’. In a letter to Newton of 18 February 1693 he speaks unabashedly of matter that ‘is found in our Suns Vortex’.
Who published the word first? Bentley’s seventh Boyle lecture was not published separately, but appeared in the 1693 volume, the last lecture of which was not given its imprimatur until 30 May that year. Locke’s book was advertised in the London Gazette #2886 for 6–10 July. I have not been able to establish exactly when Bentley’s volume appeared, but it’s not mentioned in the London Gazette before #2886.
Whatever the case, it is most likely that the term was already ‘in the air’ and history shows that it was soon widely used and, of course, it is a commonplace today.
(N.B. This post also appears on the Early Modern at Otago blog.)
Peter Anstey writes…
John Locke’s commitment to the experimental philosophy was extraordinary. In the 1690s, arguably the busiest decade of his life, Locke continued to make daily detailed records of the prevailing weather conditions at Oates, the house of Francis Masham where he resided from 1691.
Each day he would enter the day of the month, the hour, the temperature, barometric pressure, humidity, wind direction and speed, and the overall weather conditions. Sometimes he recorded three or four sets of data within a single day. Of course, Locke was not the only one in England who was collecting such data. He was merely a small part in a larger loosely connected project that aimed to construct a natural history of the air. The inspiration here was his mentor Robert Boyle whose A General History of the Air Locke had seen through the press in 1692 after Boyle’s death. Indeed Locke included a set of his own weather records from the 1660s in that work and perhaps it was the self-confessed incomplete nature of Boyle’s history that spurred Locke on to resume his weather charts in December 1691 (the very month in which Boyle died). The incompleteness of Boyle’s history is also the explanation of the fact that Locke had his own copy of the work interleaved and began to add new observations on the air.
One particularly interesting set of records is that for the month of September 1694. Here are the readings for the 4th of that month:
Day Hour Temp Barom Hygrom Wind Weather
|4||∙9||5o—||15.||2436||WS 3||covered, a shower at 21|
|24||1 ∙ 7||29∙10.||2233||very fair|
The small dot to the left of the hour indicates that the first reading was made around 9.45am. There was no standard of temperature in Locke’s day, so he provides a relative reading of 5 marks above the zero mark, which was set at temperate rather then freezing. The morning wind from the WSW was evidently quite strong: Locke’s scale is from 0 to 4. And he was up late recording that there was a rain shower at 9pm and taking another set of readings at midnight. (It is interesting to note too that he used a 24-hour clock and records made at midnight are not uncommon.)
After this entry, Locke makes the following observation:
SWALLOWS. No Swallow or Martins this day plying about the house or Moat as they used to be but every now & then 3 or 4 or more appeared & after 2 or 3 turns were gone again out of sight they generally flew very high and seemed to be passengers & to take their course southward as far as I could observe whether they were plying about the house yesterday or not I did not observe.
Then on the 19th of the month he reflects back on the swallows:
SWALLOWS The observation made 4° Sept will need some further experiments to confirm it. It being hard to take notice of their flight so as to be sure they doe not return again. But this I am certain that after that day neither SWALLOWS nor Martins were so many nor so busy as before. But yet some of them though not so frequent were to be seen till the 19th & then I went to London.
Notice the talk of the need for further experiments. Here, within a project for the systematic collection of data for a Baconian natural history, a project that involves the daily use of newly invented meteorological instruments, Locke makes a further observation and conceives of it in terms of the application of the experimental method.
So thorough are Locke’s records that, by his own admission, ‘there seldom happen’d any Rain, Snow, or other remarkable change, which I did not set down’. And what was it all for? He told Hans Sloane that with enough meteorological data ‘many things relating to the Air, Winds, Health, Fruitfulness, &c. might by a sagacious man be collected from them, and several Rules and Observations concerning the extent of Winds and Rains, &c. be in time establish’d to the great advantage of Mankind.’
Peter Anstey writes…
Many experimental philosophers were committed to the view that a science of nature would ultimately be a demonstrative science. In other words, natural philosophy should be a form of scientia based upon propositional axioms or first principles and derived via demonstrative reasoning using syllogistic logic.
This feature of much early modern experimental philosophy provides a problem for those who interpret it through the rationalism/empiricism distinction. For, it seems to be a characteristic of rationalist philosophers that they aim for the demonstrative ideal whereas the so-called empiricists, it is claimed, opted for a form of probablism. And yet many so-called empiricists were committed to the demonstrative ideal.
One such philosopher was John Locke. Interestingly, however, Locke developed his own theory of demonstration that was based upon his theory of ideas and not upon the Aristotelian conception of scientia. Locke claimed that demonstrative knowledge is not knowledge derived from true propositions but rather the perception of the agreement or disagreement of two ideas with the assistance of a third, intermediate, idea (Essay II. xvii). As such Locke’s theory of demonstration was pre-linguistic (that is, it doesn’t have to do with statements that are capable of truth or falsity), even though he freely admitted that the transition to verbal expression of these thoughts is irresistible (Essay IV. v. 3–4).
Now, Locke called his intermediate ideas proofs (Essay IV. xvii. 2). This seems to be a rather odd use of the term ‘proof’ in early modern English. It does not appear in the OED and it may be thought to typify a theory that was unusual or even idiosyncratic. It seems, however, that there might have been a precedent for this in English logic.
When we turn to Thomas Blundeville’s The Art of Logick (London, 1599, 2nd edition 1617), we find that the middle or mean term in a syllogism is called a proof. Blundeville claims that the major term and the minor term in a syllogism
are made to agree by helpe of a third Terme, called the Meane terme or proofe. (p. 137)
It is interesting to note here not only the use of the term ‘proofe’ for the mean term, but also the claim that the major and minor terms of the premises are made to ‘agree’ by the mean term. Locke’s terminology parallels this very closely, only he applies it to individual ideas like black and white rather than to propositions. For Locke it is the ideas that agree rather than the terms and the proof is the intermediate idea rather than the middle term.
Now, there is, to my knowledge, no evidence that Locke read Blundeville’s Logick and yet Blundeville’s is the only English logic text in which I have found this meaning of the term ‘proof’. So what is the origin of Locke’s terminology? If any readers can shed some light on this I’d be most grateful.
Juan Gomez writes…
As we have constantly argued for in this blog, experimental philosophy went beyond the boundaries of natural philosophy and was adopted in a number of other areas (ethics, aesthetics, theology, etc.) We have seen that this is particularly true in the case of Scotland (Turnbull, Hume, Fordyce, Reid, Hutcheson, Smith etc.), but we are yet to discuss the suitability of the experimental method of natural philosophy for enquiries into moral philosophy. In particular, we have not examined in any detail what those thinkers we have discussed would count as ‘experiments’ in formulating their moral theories. This is the topic of today’s post.
In a previous post I commented on Turnbull’s description of paintings as suitable samples or experiments for moral philosophy. But that discussion considered Turnbull’s Treatise on Ancient Painting instead of his main moral text, The Principles of Moral Philosophy. In the latter there is no explicit statement of what experiments for moral philosophy would look like, but we can get a picture of what they would amount to. Turnbull constantly writes statements where he tells us that the only method we should apply in all inquiries is one founded on experiment and observation:
- …we set about such an inquiry [moral] in the fair impartial way of experiment, and of reasoning from experiment alone…
…the whole of true natural philosophy is not, for that reason, no more than a system of facts discovered by experiment and observation; but it is a mixture of experiments, with reasonings from experiments: so in the same manner, in moral philosophy…
In fine, the only thing in enquiries into any part of nature, moral or corporeal, is not to admit any hypothesis as the real solution of appearances, till it is found really to take place in nature, either by immediate experiment, or by necessary reasonings from effects, that unavoidably lead to it as their sole cause, law, or principle.
It is only in the way of experiment, that either the science of the human mind, or of any material system can be acquired.
From these statements and the argument Turnbull develops in his book, it seems that he is using ‘experiment’ in a sense that is closer to the meaning of ‘experience’. This usage of the term is not surprising, since the French word ‘experience’ can mean both ‘experiment’ and ‘experience,’ and even in English and in Spanish the word can be used with both senses (the verb ‘experimentar’ in Spanish is used both to refer to ‘experience’ and to ‘experiment’). So it seems that ‘experiments’ in moral philosophy lose one of the connotations the term has in natural philosophy, namely the active, manipulation of nature. When Turnbull insists that in moral philosophy we can only reason by way of experiments, he is talking about observing and experiencing the way human beings behave, and founding our conclusions on such observations. So far we would have to say that there are no experiments per se in moral philosophy, but rather just experience and observation.
However, there is an aspect that does have some sort of parallel with experiments in natural philosophy. As I commented in a previous post, introspection is one of the aspects that the Scottish experimental moral philosophers used in their investigations, and this is the experimenting factor in their method. If we are to follow the methodology of experimental philosophy, then we must found all our theories on experience and observation, and completely disregard any sort of hypotheses and speculation. But when the subject of our inquiries is the human mind, our observations are limited. Yes, we can observe how other human beings behave, and that can give us some knowledge, but we cannot observe their minds. The only way anyone can observe the human mind and its operations is by looking into and experiencing their own mind, by introspection. By looking into our own minds we can construct an explanation of our constitution and behaviour based on such observations, and then we can observe others and compare experiences in order to enrich our moral theories. This is why Turnbull is constantly asking the reader not to take his word for the claims he makes, but rather experiment and look into their own minds to confirm such claims. He wasn’t the only one taking this stand: Thomas Reid also appeals to introspection and even Locke as early as Draft B of the Essay (1671) takes introspection to be a form of experiment.
So it seems that the term ‘experiment’ was tweaked for its application in moral philosophy. It is closer to what we mean by ‘experience,’ but it keeps an aspect of ‘experimenting’ that is limited to the each individual’s own mind. The question remains, however, as to whether we can actually count introspection as a proper experiment or not. The Scottish experimental moral philosophers certainly counted it just as they would count any experiment in natural philosophy.
Peter Anstey writes…
One feature of early modern experimental philosophy that has been brought home to us as we have prepared the exhibition entitled ‘Experimental Philosophy: Old and New’ (soon to appear online) is the broad range of disciplinary domains in which the experimental philosophy was applied in the 17th and 18th centuries. Some of the works on display are books from what we now call the history of science, some are works in the history of medicine, some are works of literature, others are works in moral philosophy, and yet they all have the unifying thread of being related in some way to the experimental philosophy.
Two lessons can be drawn from this. First – and this is a simple point that may not be immediately obvious – there is no distinct genre of experimental philosophical writing. Senac’s Treatise on the Structure of the Heart is just as much a work of experimental philosophy as Newton’s Principia or Hume’s Enquiry concerning the Principles of Morals. To be sure, if one turns to the works from the 1660s to the 1690s written after the method of Baconian natural history, one can find a fairly well-defined genre. But, as we have already argued on this blog, this approach to the experimental philosophy was short-lived and by no means exhausts the works from those decades that employed the new experimental method.
Second, disciplinary boundaries in the 17th and 18th centuries were quite different from those of today. The experimental philosophy emerged in natural philosophy in the 1650s and early 1660s and was quickly applied to medicine, which was widely regarded as continuous with natural philosophy. By the 1670s it was being applied to the study of the understanding in France by Jean-Baptiste du Hamel and later by John Locke. Then from the 1720s and ’30s it began to be applied in moral philosophy and aesthetics. But the salient point here is that in the early modern period there was no clear demarcation between natural philosophy and philosophy as there is today between science and philosophy. Thus Robert Boyle was called ‘the English Philosopher’ and yet today he is remembered as a great scientist. This is one of the most important differences between early modern x-phi and the contemporary phenomenon: early modern x-phi was endorsed and applied across a broad range of disciplines, whereas contemporary x-phi is a methodological stance within philosophy itself.
What is it then that makes an early modern book a work of experimental philosophy? There are at least three qualities each of which is sufficient to qualify a book as a work of experimental philosophy:
- an explicit endorsement of the experimental philosophy and its salient doctrines (such as an emphasis on the acquisition of knowledge by observation and experiment, opposition to speculative philosophy);
- an explicit application of the general method of the experimental philosophy;
- acknowledgment by others that a book is a work of experimental philosophy.
Now, some of the books in the exhibition are precursors to the emergence of the experimental philosophy (such as Bacon’s Sylva sylvarum). Some of them are comments on the experimental philosophy by sympathetic observers (Sprat’s History of the Royal Society), and others poke fun at the new experimental approach (Swift’s Gulliver’s Travels). But this still leaves a large number of very diverse works, which qualify as works of experimental philosophy. Early modern x-phi is a genre free zone.
Peter Anstey says…
In one of the great statements of philosophical humility the English philosopher John Locke characterised his aims for the Essay concerning Human Understanding (1690) in the following terms:
- The Commonwealth of Learning, is not at this time without Master-Builders, whose mighty Designs, in advancing the Sciences, will leave lasting Monuments to the Admiration of Posterity; But every one must not hope to be a Boyle, or a Sydenham; and in an age that produces such Masters, as the Great – Huygenius, and the incomparable Mr. Newton, with some other of that Strain; ’tis Ambition enough to be employed as an Under-Labourer in clearing Ground a little, and removing some of the Rubbish, that lies in the way to Knowledge (Essay, ‘Epistle to the Reader’).
Locke regarded his project as the work of an under-labourer, sweeping away rubbish so that the ‘big guns’ could continue their work. But what is it that unites Boyle, Sydenham, Huygens and Newton as Master-Builders? It can’t be the fact that they are all British, because Huygens was Dutch. It can’t be the fact that they were all friends of Locke, for when Locke penned these words he almost certainly had not even met Isaac Newton. Nor can it be the fact that they were all eminent natural philosophers, after all, Thomas Sydenham was a physician.
In my book John Locke and Natural Philosophy, I contend that what they had in common was that they all were proponents or practitioners of the new experimental philosophy and that it was this that led Locke to group them together. In the case of Boyle, the situation is straightforward: he was the experimental philosopher par excellence. In the case of Newton, Locke had recently reviewed his Principia and mentions this ‘incomparable book’, endorsing its method in later editions of the Essay itself. Interestingly, in his review Locke focuses on Newton’s arguments against Descartes’ vortex theory of planetary motions, which had come to be regarded as an archetypal form of speculative philosophy.
In the case of Huygens, little is known of his relations with Locke, but he was a promoter of the method of natural history and he remained the leading experimental natural philosopher in the Parisian Académie. In the case of Sydenham, it was his methodology that Locke admired and, especially those features of his method that were characteristic of the experimental philosophy. Here is what Locke says of Sydenham’s method to Thomas Molyneux:
- I hope the age has many who will follow [Sydenham’s] example, and by the way of accurate practical observation, as he has so happily begun, enlarge the history of diseases, and improve the art of physick, and not by speculative hypotheses fill the world with useless, tho’ pleasing visions (1 Nov. 1692, Correspondence, 4, p. 563).
Note the references to ‘accurate practical observation’, the decrying of ‘speculative hypotheses’ and the endorsement of the natural ‘history of diseases’ – all leading doctrines of the experimental philosophy in the late seventeenth century. So, even though Sydenham was a physician, he could still practise medicine according to the new method of the experimental philosophy. In fact, many in Locke’s day regarded natural philosophy and medicine as forming a seamless whole in so far as they shared a common method. It should be hardly surprising to find that Locke held this view, for he too was a physician.
If it is this common methodology that unites Locke’s four heroes then we are entitled to say ‘Locke’s Master-Builders were experimental philosophers’. I challenge readers to come up with a better explanation of Locke’s choice of these four Master-Builders.