Should we call Newton a ‘Structural Realist’?
Kirsten Walsh writes…
At our symposium last week, someone wondered if we can characterise Newton as a ‘structural realist’. It is certainly anachronistic to attempt to interpret Newton’s epistemic stance in light of the present-day scientific realism debate. But the sin of anachronism may be forgiven, if it advances our understanding. So let us see what advantages this interpretation may provide.
Briefly, structural realism is the view that epistemically, a scientist should only commit herself to the mathematical or structural content of her theories, and remain sceptical about the unobservable entities posited by those theories.
To characterise Newton as a structural realist, one might make the following argument:
- P1. Newton is a realist about his theories, but not about his hypotheses.
P2. Newton’s theories make claims about theoretical structures, whereas his hypotheses make claims about unobservable theoretical entities.
C. Therefore, Newton is a realist about theoretical structures, but not about unobservable theoretical entities.
Firstly, consider Newton’s hypothesis/theory distinction. In a previous post I argued that Newton claims that his doctrine of light and colours is a theory, not a hypothesis, for three reasons:
- T1. It is certainly true, because it is supported by (or deduced from) experiment;
T2. It concerns the physical properties of light, rather than the nature of light; and
T3. It has testable consequences.
In contrast, he attaches no special epistemic merit to his corpuscular hypothesis because:
- H1. It is not certainly true, because it is not supported by experiment;
H2. It concerns the nature of light; and
H3. It has no testable consequences.
T1 and H1 support P1. They tell us that Newton is a realist about theories because they can be shown to be true on the basis of experiment. Moreover, he is not a realist about hypotheses because they cannot be shown to be true on the basis of experiment. This highlights an important feature of Newton’s methodology: Newton is only epistemically committed to those things that are demonstrated experimentally.
T2 and H2 appear to support P2, but only if the ‘entity/structure’ distinction maps onto Newton’s ‘nature/physical properties’ distinction. Prima facie, it does. While Newton probably wouldn’t have been comfortable with the entity/structure distinction, the structural realist debate is often framed in terms of the nature/physical properties distinction. For example, here’s how the Stanford Encyclopedia of Philosophy describes the structural realist position:
- Structural realism is often characterised as the view that scientific theories tell us only about the form or structure of the unobservable world and not about its nature. This leaves open the question as to whether the natures of things are posited to be unknowable for some reason or eliminated altogether.
So it looks like the argument for characterising Newton as a structural realist is well-supported by Newton’s distinction between theory and hypothesis. But what do we gain by characterising Newton in this way?
Chris Smeenk recently pointed out to me in an email that the structural realist label identifies a distinctive feature of Newton’s methodology. Namely, that he is epistemically committed to his abstract mathematical structures. He is not an instrumentalist about his theories, but neither is he a realist about the nature of the phenomena they describe. This might shed some light on the optical debate of the early 1670s, for unlike his contemporaries, Newton does not think there is a contradiction in believing that his theory of light is true, while not committing himself to any particular doctrine regarding the nature of light.
Is this a large enough pay-off to warrant the offence of anachronism? What do you think?
In this brief post, I have only considered Newton’s attitudes to his own theories. There are other questions to be raised in connection with structural realism, for example, is Newton a structural realist about the history of science? In other words, what is Newton’s epistemic commitment to the theories of his predecessors? I shall leave this question for another time.
On another note, we were very pleased with how last week’s symposium went. We look forward to telling you all about it next Monday.
Lost in translation
Peter Anstey writes…
Sometimes our historiographical categories can so dominate the way we approach the texts of great dead philosophers that we project them onto the texts themselves. Unhappily this is all too common among historians of early modern philosophy who take as their terms of reference the distinction between rationalism and empiricism.
For example, Stephen Priest, in The British Empiricists (2nd ed. 2006, p. 8) claims:
- Although historians of philosophy claim that Kant invented the empiricist/rationalist distinction and retrospectively imposed it on his seventeenth- and eighteenth-century predecessors, this is a historical mistake. The distinction was explicitly drawn using the words “empiricists” and “rationalists” at least as early as 1607, when the British empiricist Francis Bacon (1561–1626) wrote: “Empiricists are like ants; they collect and put to use; but rationalists are like spiders; they spin threads out of themselves” and:
Those who have handled sciences have been either men of experiment or men of dogmas. The men of experiment are like the ant; they only collect and use; the reasoners resemble spiders, who make cobwebs out of their own substance.
[…] Leaving aside the use of the words “rationalism” and “empiricism” (or similar) the distinction between the two kinds of philosophy is as old as philosophy itself. It is true that many rationalist and empiricists do not describe themselves as rationalists or empiricists but that does not matter. Calling oneself “x” is neither necessary nor sufficient for being x.
However, a careful reading of Bacon’s Latin reveals that he is not using the Latin equivalents of ‘empiricists’ and ‘rationalists’, but rather empirici and rationales, terms that have quite different meanings in Bacon. For Bacon, the empirici are those who focus too much on observation and the works of their hands (New Organon, I, 117). Quacks who prescribe chemical remedies without any knowledge of medical theory are commonly called empirici and the term is usually a pejorative in the early seventeenth century (see De augmentis scientiarum, Bk IV, chapter 2). By contrast rationales are those who ‘wrench things various and commonplace from experience… and leave the rest to meditation and intellectual agitation’ (New Organon, I, 62).
Another example of projecting the rationalism/empiricism distinction onto a text is found in the recent English edition of Diderot’s Pensées sur l’interpretation de la nature. Diderot’s work contains a very interesting discussion of philosophical methodology. Article XXIII says,
- Nous avons distingué deux sortes de philosophies, l’expérimentale et la rationnelle.
The translation in the Clinamen Press (1999, p. 44) edition reads:
- We have identified two types of philosophy – one is empirical and the other rationalist.
But Diderot doesn’t contrast empirical with rationalist. Rather the contrast is between experimental philosophy (la philosophie expérimentale) and rational and the context makes it clear that rationnelle here is used to refer to what the English called speculative philosophers. The terminology and the content of Diderot’s discussion makes far more sense when read in the light of the experimental/speculative distinction. Yet this is lost in the English translation.
Having pointed out two examples of reading the traditional historiography into the texts themselves, I should like to end with a note of caution. Those of us who regard the experimental/speculative distinction as having more explanatory value than the traditional post-Kantian terms of reference also need to be aware that we too can fall into the same trap of reading the ESD into the texts under study and not allow the texts to speak for themselves.
Tennemann on Empiricism and Rationalism
Alberto Vanzo writes…
Wilhelm Gottlieb Tennemann was a very influential Kantian historian of philosophy. His textbook on the history of philosophy had five German editions. Its two English translations were reprinted throughout the nineteenth century. As a result, many of Tennemann’s judgements and historiographical classifications ended up being accepted, more or less consciously, by generations of students, philosophers, and historians.
One of Tennemann’s classifications that became standard is the distinction of most early modern philosophers into empiricists and rationalists (RED). Tennemann’s lists of early modern empiricists and rationalists are now standard. His reading of Hume as bringing Locke’s empiricism to its sceptical consequences, or of Kant as synthesizing empiricism and rationalism, are still widely accepted.
At the basis of Tennemann’ historiography is an outlook that few, if any, would agree with today. Tennemann asks: what should the history of philosophy be, over and above the history of ideas? He answers:
History of Philosophy […] can be neither history of philosophers, nor history of ideas [Philosopheme]. It includes both, but it subordinates them to a higher purpose and point of view. This is the exposition of the formation and development of philosophy as science.According to Tennemann, Kant laid the foundations for philosophy as science. Thanks to the Kantian revolution, we know the one true philosophy.
Kant did not create this true philosophy ex nihilo. Kantian philosophy is the crowning of endless attempts to develop a true science. It is the synthesis of the best insights of Kant’s predecessors. According to Tennemann, historians of philosophy should trace the gradual development of those insights from ancient Greece to their Kantian epilogue.
This Kantian stance has several interesting consequences. Let me focus on two of them.
1. Kant’s philosophy sharply distinguishes a priori questions belonging to metaphysics and (what we now call) epistemology from the empirical inquiries of natural science. It focuses on the former and leaves the latter to (what we now call) working scientists. Consistent with his intent to trace the ancestry of philosophy in the Kantian sense, Tennemann makes only passing remarks on the development of natural philosophy. He repeats several times that Descartes was mainly interested in natural philosophy. However, Tennemann’s Descartes comes across as the “philosopher of pure inquiry” because, for Tennemann, “pure inquiry” was the truly philosophical part of his thought – philosophical in Kant’s sense of the term.
2. A history of early modern philosophy can be organized on the basis of various criteria: chronological and geographical factors, actor categories like experimental philosophy, or later notions like those of empiricism and rationalism. What criteria are the best? Tennemann answers as follows. History of philosophy should describe reason’s progress towards Kantian philosophy. To this end, it is best to group early modern authors on the basis of their views on two typically Kantian themes: whether there are non-empirical concepts and whether we can have substantive a priori knowledge. The results of these groupings are Tennemann’s accounts of the evolution of empiricism and rationalism, converging in Kant’s final synthesis.
Tennemann is conscious that the results of this choice are somewhat arbitrary. While he places Berkeley between Locke and Hume in his parade of empiricist philosophers, he acknowledges that Berkeley was also influenced by the rationalists Descartes and Malebranche.
Since the early 1980s, the fact that Descartes was more interested in natural philosophy than in “pure inquiry”, or the affinities between Berkeley and Malebranche, are adduced to claim that the narratives of early modern philosophy based on the RED are broken-backed. Tennemann, probably the first historian to develop such a narrative in detail, openly acknowledged those facts. Yet he based his historiography on the RED nevertheless. This is because that distinction was the most functional to his views on what philosophy is and what its history should accomplish.
Tennemann’s case teaches us that no amount of detailed historical excavations or textual analyses will suffice to tell us whether we should accept the RED, reform it, or replace it with some other master narrative of early modern philosophy. To make such a choice, we should have clear ideas on what we should identify this philosophy that we are studying with, and on what we take our tasks as historians of philosophy to be. Tennemann gave fully explicit answers and he was coherent with them in developing a historiography based on the RED. How should we answer those questions?
Thomas Reid and the dangers of introspection
Juan Gomez writes…
In the upcoming symposium we are hosting here at the University of Otago, I will be giving a paper on the features of the experimental method in moral philosophy (you can read the abstract). One of the salient features of this method was the use of introspection as a tool to access the nature and powers of the human mind. In fact, some Scottish moral philosophers acknowledge introspection as the only way we can get to know the nature of our mind. George Turnbull and David Fordyce were proponents of such claims, as well as Thomas Reid. The latter, in the Introduction to his Inquiry into the Human Mind (1764) draws an analogy with anatomy where he tells us that, in the same way we gain knowledge of the body by dissecting and observing it, we must perform an ‘anatomy of the mind’ to “discover its powers and principles.” The problem is that unlike the anatomist who has multiple bodies to observe, the anatomist of the mind can only look into his own mind:
- It is his own mind only that he can examine with any degree of accuracy and distinctness. This is the only subject he can look into.
Reid notices that this is not good for our experimental inquiry into the human mind, since a general law or rule cannot be deduced from just one subject:
- So that, if a philosopher could delineate to us, distinctly and methodically, all the operations of the thinking principle within him, which no man was ever able to do, this would be only the anatomy of one particular subject; which would be both deficient and erroneous, if applied to human nature in general.
But this obstacle doesn’t persuade Reid to give up introspection (Reid uses the term ‘reflection’) since it is “the only instrument by which we can discern the powers of the mind.” What we have to do is be very careful:
- It must therefore require great caution, and great application of mind, for a man that is grown up in all the prejudices of education, fashion, and philosophy, to unravel his notions and opinions, till he find out the simple and original principles of his constitution… This may be truly called an analysis of the human faculties; and, till this is performed, it is in vain we expect any just system of the original powers and laws of our constitution, and an explication from them to the various phaenomena of human nature.
Scottish moral philosophers were faced with this dilemma. On one hand, in order to access the nature of the human mind, they had to rely on a tool that could only examine and observe one particular mind, making the generalization of the principles discovered impossible; on the other hand, introspection was the only way to access the human mind, since by observing others we cannot gain any knowledge of what goes on in their minds, at least not accurately. The solution, consistent with the spirit of the experimental method, was to focus only on what we can experience and observe, and follow this evidence only as far as it can take us. Therefore as Reid points out, we are to use reflection with
- caution and humility, to avoid error and delusion. The labyrinth may be too intricate, and the thread too fine, to be traced through all its windings; but, if we stop where we can trace it no farther, and secure the ground we have gained, there is no harm done; a quicker eye may in time trace it farther.
These comments by Reid show that even when the problems of relying on introspection were explicitly recognized, the Scottish moral philosophers still used it as their way to access the nature of the human mind. Since introspection was considered to be the only reliable way into the workings of the human mind, they had to be very careful with the use they made of it. This caution was achieved by following the methodology of the experimental method, where they could only go as far as their observations would take them, and their conclusions had to be confirmed by the particular experience of many. But such limits to the conclusions drawn from introspection cast doubt on the status of the exercise of reflection: could introspection really be considered ‘experimental,’ or was the justification given by the moral philosophers (Reid in particular) just a rhetorical device? This is a problem that requires a lot more space than a blog post, but if you have any particular thoughts and comments I am looking forward to receiving and discussing them with you.
