You can watch all the talks sequentially as a YouTube Playlist or follow the links below. To fit on YouTube, the videos of the speakers had to be divided into two parts: talk and questions. (Speaker names link to their websites; please click on a talk title to see the associated abstract.)
Stein’s notion of Becoming and the Metaphysics of Time (Oliver Pooley)
Many have taken the absence of objective, frame-independent simultaneity in relativistic physics as providing a reason either to accept a “block universe” metaphysics of time or to deny that there can be genuine future indeterminateness. Howard Stein has twice had occasion to take issues with arguments of this ilk. In the late 60s he responded to then recently published arguments by Hilary Putnam and Wim Rietdijk. In the early 1990s he responded, with broader scope, to a similar argument of Nicholas Maxwell’s.
The high regard in which these two papers of Stein’s are rightly held contrasts rather markedly with their impact on the debate. Indeed, there seems to be no clear consensus concerning what one should conclude from Stein’s re-exploration of the territory. Most interested parties, I think, continue either to subscribe to the block universe view or to accept the existence of a metaphysically preferred simultaneity relation.
In my talk I will be concerned with whether Stein provides the resources for a metaphysical position that fits neither of these moulds. In particular I will connect Stein’s claims with Nuel Belnap’s (explicitly Stein-inspired) Branching Spacetimes framework and with recently popular notions of relative truth. Finally I will be concerned with the question of whether some such view can accommodate the pronouncements of certain physicists working on casual set theory, who deny the analogues for causal set theory of both a preferred simultaneity relation and a block universe metaphysics.
Instrumental Metaphysics (Karim Thébault)
In his 1989 paper “Yes but…Some Sceptical Remarks on Realism and Anti-Realism” Stein distinguishes between two forms of instrumentalism. On the one hand, we have a “trite form of debunking instrumentalism” in which scientific theories are asserted to be “nothing but instruments for calculating the outcomes of experiments.” On the other hand, we have a “liberalised instrumentalism” in which the instrumental function of theories is enriched to include features, such as representing phenomena, traditionally considered the reserve of the realist. From the viewpoint of liberalised instrumentalism a natural opportunity is created for metaphysical posits to play useful heuristic and justificatory roles in scientific practice. In this talk I will investigate the potential of two such posits. The first relates to the ontology of time and leads to a new heuristic for theory construction in quantum gravity. The second relates to multiple realiziability of Hawking radiation and leads to the justification of a new form of scientific inference, “analogue simulation”.
Reflections on the Structure of Cosmological Knowledge (Chris Smeenk)
Stein has characterized one of the central problems in accounting for our knowledge in physics as that of getting the laboratory, or observatory, inside the theory—that is, of understanding how the mathematical structures of fundamental physical theories have empirical content. He has argued that physicists respond to this problem by giving schematic representations of observers and experiments. I will explore some ramifications of this way of thinking about empirical content for contemporary cosmology. One goal of observational cosmology is to measure the six basic parameters appearing in the standard model of cosmology. These parameters are well-defined if the universe is suitably approximated at some scale by a perturbed FLRW model. The enormous extrapolations involved in the standard model are often justified by the consistent determination of these parameters via a variety of methods. Here I will consider two recent debates regarding this approach to cosmology, inspired by Stein’s emphasis on schematic characterizations of observers. The first debate regards how the highly symmetric FLRW models relate to describing the real universe, at small scales where it is very lumpy. The second regards the impact of different ways of characterizing the propagation of light through a cosmological spacetime on the determination of cosmological parameters (such as H0).
Time (Hole?) Machines (John Manchak)
Within the context of general relativity, we consider a type of “time machine” and introduce the related “hole machine”. We review what is known about each and add results of our own. We conclude that (so far) the hole machine advocate is in a better position than the time machine advocate.
“On the Present State of the Philosophy of Quantum Mathematics”, 35 Years Later (Tom Pashby)
I take up two Steinian themes concerning the interpretation of quantum mechanics and evaluate them in light of the intervening years. The first of these concerns Stein’s bold claim (made in 1970) that: “Quantum Mechanics poses no special problems of an epistemological kind”. I argue that this idea is best supported by more recent developments in quantum measurement theory tying (what Stein calls) the “logic of eventualities” not to the lattice of projections but the algebra of effects (i.e., POVMs). The second concerns his analogy between 19th century investigations of the aether and 20th century investigations of quantum mechanics. Tracing the recent history of uses of similar analogies in the quantum foundations literature, I hone in on some conflicting metaphysical and methodological assumptions made by contemporary thinkers that seem to fit the contours of Stein’s analogy.
Schematizing the Observer in Physical Theory (Erik Curiel)
It is commonly held among philosophers of science that one need not consider the explicit theoretical representation of observation and experimentation in analyzing how a physical theory gains empirical content and what that empirical content is (for example, in articulating an adequate semantics of physical theory). It is a theme in Howard Stein’s work, to the contrary, that one cannot fully understand the nature and content of scientific knowledge, and especially its empirical content, without having an understanding of how (some of) that knowledge is in fact collected experimentally, which includes an understanding of how theory and experiment come into substantive and fruitful contact in practice. I defend this view, arguing that one cannot grasp the nature of the epistemic warrant we do have for scientific knowledge in all its guises (as achieved state, as basis for evidentiary relations, as ground for future investigation, and so on) without understanding the ways in which observation and experimentation are actually represented in our best physical theories—how the laboratory gets into the theory. That is what the empirical content of a theory must ultimately devolve upon, since our most secure epistemic warrant comes from experimentally derivable empirical knowledge. Thus, as I will argue along Carnapian lines, we cannot grasp the character of that empirical content without understanding what epistemic warrant we have for it and how we come to have that warrant.
“—It would be possible to do a lengthy dialectical number on this;” (Wayne Myrvold)
As Howard Stein has noted, there is a tendency, in the literature on scientific realism and anti-realism, to take it as unproblematically true that terms such as “ether”, “phlogiston”, and “caloric”, as used by scientists of the 19th century, failed to refer, whereas scientific realists contend that terms such as “atom” and “oxygen” did refer. The supposedly referring terms are the ones that have been retained, and the supposedly non-referring terms are those that have been dropped. Given that, according to current science, nothing has all the properties attributed by 19th century scientists to either ether or atoms, the question arises (and is raised by Stein) whether these judgments of reference and nonreference have any basis. In this talk, I will contend that there is a twofold danger of being beguiled by matters of terminological shift and retention. Retention of a term can mask a deep conceptual change, and abandonment of a term may obscure continuity of concept. I will briefly illustrate these points with respect to the terms “ether”, “phlogiston”, and “caloric”, via imagining nearby possible worlds in which these terms were retained. The lesson to be drawn is that historical theory changes have involved a nuanced combination of conceptual continuity and change that is obscured by simple judgments of reference success and failure guided by retention and nonretention of terms.
A Difference That Makes a Difference? Stein on Realism, Instrumentalism, and Intellectually Nourishing Snacks (Kyle Stanford)
In his classic paper “Yes, But…Some Skeptical Remarks on Realism and Anti-Realism”, Howard Stein argues that once simplistic versions of realism and instrumentalism have been sophisticated in ways that are independently required in order to make them at all plausible, there remains no “difference that makes a difference” between them. Moreover, he argues, in the work of the deepest scientists and natural philosophers,“important aspects of realism and instrumentalism are present together in such a way that the alleged contradiction between them vanishes” (47). I first try to reconstruct Stein’s argument in full, suggesting that what it ultimately recommends is a kind of ‘methodological omnivory’ or willingness to take all successful scientific theories seriously enough to inhabit them, fully explore their consequences or implications, and seek to extend them to new phenomena, even when we are regarding those theories simply as powerful conceptual or cognitive aids to our investigation of nature and even if we cannot see how those theories even could provide us with an intelligible or coherent description of some part of of nature itself. I then go on to resist Stein’s conclusion, however, arguing that realists (whether classical or selective in their realism) and instrumentalists have different expectations about what further scientific investigation will uncover, that this difference remains even after we have sophisticated each position in the ways Stein recommends, and that this difference makes a difference to how realists or instrumentalists do or should conduct further scientific inquiry, especially in how they should be respectively willing to invest the scarce resources available for pursuing the scientific enterprise itself. And I suggest that Stein’s enthusiasm for methodological omnivory stands in some tension with the idea that his view somehow ratifies or validates any part of the realist’s own distinctive epistemological commitments.
Newton’s Epistemic Triad (Kirsten Walsh)
Isaac Newton condemned the use of hypotheses with his (in)famous methodological statement, Hypotheses non fingo, and yet employed hypotheses explicitly in every edition of the Principia. Some commentators have argued that Newton was working with several inconsistent notions of ‘hypothesis’: specifically, the hypotheses he used in the Principia are not the sort that he railed against in the General Scholium at the end of that book. Other commentators argue that Newton’s methodological statements are simply inconsistent with how he actually proceeded: for example, they argue that the queries introduced by Newton at the end of his Opticks are hypotheses-in-disguise. I argue that Newton’s methodological pronouncements and his use of hypotheses are far more consistent than previously thought. I consider Newton’s methodology within the framework of his three-way epistemic distinction between theories, which are certain and experimentally confirmed, hypotheses, which are uncertain and speculative, and queries, which are not certain, but provide the proper means to establish the certainty of theories. I call this division Newton’s ‘epistemic triad’. I argue that Newton’s hypotheses and queries have distinctive and vital supporting roles within this epistemic triad. This provides us with a much more consistent picture of Newton’s methodology.
Quantum Monads (Simon Saunders)
The quantum histories formalism is broadly neutral between dynamical collapse, pilot wave, and Everettian quantum theory, so it is in a certain sense common ground to the main contenders for a ‘realist’ quantum theory. I shall demonstrate the strong resemblance between certain coarse-grainings of quantum histories and monads, in roughly Leibniz’s sense. Compatible decoherent histories associated with a quasiclassical realm, in Gell-Mann and Hartle’s sense, are of particular interest, but I shall also consider a more general notion of compatibility that may apply to non-decohering histories.
Newton’s Numerator in 1685: A Year of Gestation (George E. Smith)
Howard Stein has rightly argued that Newton did not derive his claim that gravity varies as the mass of the attracting body from any celestial phenomenon, reminding all that Roger Cotes had put this point forcefully to Newton in early 1713. Newton’s manuscripts from 1685, the year in which the Principia was taking shape, show that Cotes was not telling him anything that he had not known all along. His preoccupation during the first half of that year, however, was not with this term in the numerator of what became his law of gravity, but with the other term, viz. that gravity varies as the mass of the attracted body—or as Émilie Du Châtelet later put it in her commentary on the Principia, “The attractive force of our Earth proportions itself [se proportionne] to the mass of the body it attracts.” The talk will examine the efforts Newton put into this principle and its implications during 1685, including the one to which Stein called our attention, viz. that no phenomenon within our planetary system can show that gravity varies as the mass of the attracting body.
Absolute Space and Newton’s Theory of Relativity (Robert DiSalle)
Newton’s metaphysical picture of space and time provides the conceptual background for hist theory of motion. Philosophical discussions of absolute space and time, however, underemphasize Newton’s concern with the relativity of motion. From a modern perspective, this is usually seen as a concern that Newton himself did not take seriously enough, especially in comparison with contemporaries such as Huygens and Leibniz. In one sense, however, Newton pursued the problem of the relativity of motion further than his contemporary critics. In fact, while they defended the relativity of motion as a general principle, only Newton developed what may legitimately be called a theory of relativity: first, a systematic theoretical account of what is objective in the description of physical interactions, and a principled distinction between the objective properties and those that depend on the choice of a frame of reference; second, a critical analysis of accepted concepts, revealing the extent to which they represent partial or relative perspectives on the physically objective quantities. On this basis Newton articulated, more clearly than any of his contemporaries, the conceptual revisions imposed by the relativity of motion on prevailing notions of force, inertia, and causality. We can see this from the history of his use of the Galilean relativity principle, which became Corollary V to the Laws of Motion. Moreover, while his critics demanded a mechanistic alternative to his theory of gravitation, Newton not only saw the empirical power of his theory, and its exemplary power for the theory and practice of physics in general; he also saw that the peculiar nature of gravity placed the problem of the relativity of motion in a dramatically new light. This is seen in his development and use of Corollary VI.
By studying the progress of Newton’s thought about these relativity principles, and the profound changes in his views between early manuscripts such as De Gravitatione and the first drafts of the Principia, we can see why Newton did not regard them as undermining his aim to determine “the true motions” in the solar system. On the contrary, he saw it as enabling him to separate the local problem of “true motion” for a given system of bodies, from the global problem of how that system might be moving with respect to absolute space. In other words, Newton, having acknowledged that absolute space is unobservable, and motion with respect to it therefore unknowable, nonetheless could solve the problem of “the system of the world”. Indeed, the history of his thinking shows that Newton introduced the theory of absolute space precisely in order to articulate his theory of relativity.
Methodological Structuralism (Michael Friedman)
Methodological structuralism is an alternative to both structural realism and positivist or instrumentalist versions of structuralism—such as, arguably, that developed by Rudolf Carnap in his work on Ramsey sentences. It takes inspiration from earlier work in this vein by Howard Stein, who has defended a notion of abstract structures in the phenomena that is intended to satisfy the justifiable demands of both realism and instrumentalism. It also takes inspiration from recent work by George E. Smith on what he calls theory-mediated measurement. Following the examples of both Stein and Smith, the view defended here begins with Newton’s treatment of gravitational force as a measurable mathematical quantity while also remaining agnostic about the deeper causal mechanisms underlying this force. The view defended here could therefore also be called “Newtonian Structuralism”.
Engineering Design Principles in Culture, Science, and the Architecture of Nature (William Wimsatt)
A number of features are characteristics of good design, or inevitable features of the design process, both in engineering and in organic nature. I will consider a few of them. Robustness is used by scientists as a criterion for reality, and the presence of multiple arguments or means of detection or derivation of a result both increases its reliability and allows calibrating the different means of access against one another, yielding calibration, and detection of error conditions. In nature it is an important source of reliability. Modularity or near-decomposability of elements of a system allows independent modifiability, localization of error and its effects, and the combination of elements in different ways to construct a number of different devices for different purposes. This is important in biology, in computer programs, and in the evolution of technology. Differential generative entrenchment, or different magnitude of downstream consequences confers different resistance to evolutionary change. Changes are skewed towards those with smaller effect, and the rarer changes of deeply entrenched elements both have a far greater chance of having negative consequences, and if adaptive, have more revolutionary positive consequences. This explains patterns of change in biology, in the evolution of technology, and in science. These principles should be characteristic of organization in any evolved systems.
On Skepticism about the Ideal (William Tait)
There is a historic skepticism about mathematics that hangs on the fact that the objects of mathematics, structures and their elements—numbers, functions, sets, etc., are ideal, i.e. that empirical facts, facts about the natural world, have no relevance to the truth of propositions about them. Of course, the view that ‘existence’ simply means empirical existence, so that the term is misused applied to ideal things can be countered only on pragmatic grounds, that we use the term in other contexts and that it is very useful there. The rejection of ideal existence becomes meaningful only if one has a transcendental ground on which to stand and judge applications of the term. I believe that the ground, at least implicitly, has been a wrong thesis about how language works, namely the view that genuine reference to objects presupposes a non-linguistic interaction with them. And that is what I want to talk about. My argument draws on a reading of Wittgenstein’s Philosophical Investigations, a reading which is more positive than a more common one according to which he, himself, was a skeptic.
Inertial Frame Functionalism (Eleanor Knox)
I defend a version of functionalism about spacetime in which spacetime is whatever defines the structure of inertial frames. I illustrate the case with some thoughts about Newtonian spacetime, and examine the relation between this view and some themes in Stein’s work.
The Changing Role of Geometrical Definitions in Newton’s Metaphysics of Space (Zvi Biener)
I argue that De Gravitatione (DG) does not represent the Newtonian position on the metaphysics of space. I do so by focusing on Newton’s account of definition. First, I detail Newton’s account, the role definitions play axiomatic-deductive contexts (according to Newton), and the difference between definitions’ existential commitments within purely geometrical and natural-philosophical modes of inquiry. Second, I show that, according to Newton, Principia‘s definitions are methodologically different than the DG‘s. Third, I argue that this difference indicates that the existential commitments of the Principia are unlike DG‘s, especially concerning absolute space. Specifically, I argue that Newton’s commitment to absolute space in the Principia (particularly the later editions) is considerably weaker and more nuanced than the robust spatial realism of DG. I close by considering the implications of this view for the idea that Newtonian physics relies on a commitment to absolute space.
The Two Cultures and Goethe’s Rejection of Newton (André Carus)
Goethe’s notorious rejection of Newtonian science was the focus for much of the discussion that has continued—fitfully—since C.P. Snow under the heading of “the two cultures”. Goethe’s understanding of Newton, however, was shaped by materialist philosophers such as d’Holbach. This picture made it easy to hold—Newtonian—mechanistic science responsible (and, it was widely held, only mechanism made the application of mathematics to science possible) for all the aspects of modernity Goethe disliked so much (and we continue to dislike). Even Cassirer, perhaps the most heroic bridge-builder ever, across the divide between Goethe and Newton, largely accepted the traditional picture of Newton, and ended up in spectacular contortions. But Howard Stein freed Newton from this traditional metaphysical and ontological burden—too late, of course, to undo the accumulated damage, but we should at least be willing to undo it in retrospect and acknowledge that it was unnecessary, and that there is ultimately no fundamental conflict, though perhaps a kind of trade-off, between Goethe’s and Newton’s most fundamental convictions.