Recent philosophical discussions about metaphysical indeterminacy have been substantiated with the idea that quantum mechanics, one of the most successful physical theories in the history of science, provides explicit instances of worldly indefiniteness. Against this background, several philosophers underline that there are alternative formulations of quantum theory in which such indeterminacy has no room and plays no role. A typical example is Bohmian mechanics in virtue of its clear particle ontology. Contrary to these latter claims, this paper aims at showing (...) that different pilot-wave theories do in fact instantiate diverse forms of metaphysical indeterminacy. Namely, I argue that there are various questions about worldly states of affairs that cannot be determined by looking exclusively at their ontologies and dynamical laws. Moreover, it will be claimed that Bohmian mechanics generates a new form of modal indeterminacy. Finally, it will be concluded that ontological clarity and indeterminacy are not mutually exclusive, i.e., the two can coexist in the same theory. (shrink)

The idea that there are some facts that call for explanation serves as an unexamined premise in influential arguments for the inexistence of moral or mathematical facts and for the existence of a god and of other universes. This book is the first to offer a comprehensive and critical treatment of this idea. It argues that calling for explanation is a sometimes-misleading figure of speech rather than a fundamental property of facts.

At the core of the recent debate over moral debunking arguments is a disagreement between explanationist and modalist approaches. Explanationists think that the lack of an explanatory connection between our moral beliefs and the moral truths, given a non-naturalist realist conception of morality, is a reason to reject non-naturalism. Modalists disagree. They say that, given non-naturalism, our beliefs have the appropriate modal features with respect to truth -- in particular they are safe and sensitive -- so there is no problem. (...) -/- There is something of a stand-off here. I argue, though, that by looking at the role explanatory and modal factors have to play in theory choice more generally, and, in particular, by considering the practice of theory choice in science, we can see that the explanationist is right. The lack of an explanatory connection between our moral beliefs and the moral truths is a reason to reject non-naturalist realism about morality. (shrink)

My aim in this paper is twofold: to distinguish two notions of naturalness employed in beyond the standard model physics and to argue that recognizing this distinction has methodological consequences. One notion of naturalness is an “autonomy of scales” requirement: it prohibits sensitive dependence of an effective field theory’s low-energy observables on precise specification of the theory’s description of cutoff-scale physics. I will argue that considerations from the general structure of effective field theory provide justification for the role this notion (...) of naturalness has played in BSM model construction. A second, distinct notion construes naturalness as a statistical principle requiring that the values of the parameters in an effective field theory be “likely” given some appropriately chosen measure on some appropriately circumscribed space of models. I argue that these two notions are historically and conceptually related but are motivated by distinct theoretical considerations and admit of distinct kinds of solution. (shrink)

Naturalness is an extra-empirical quality that aims to assess plausibility of a theory. Finetuning measures are often deputized to quantify the task. However, knowing statistical distributions on parameters appears necessary. Such meta-theories are not known yet. A critical discussion of these issues is presented, including their possible resolutions in fixed points. Both agreement to and skepticism of naturalness’s utility remains credible, as is skepticism to any extra-empirical theory assessment that claims to identify “more correct” theories that are equally empirically adequate. (...) The severe implications of SEETA are set forward in some detail. We conclude with a summary and discussion of the viability of three main viewpoints toward naturalness and finetuning, where the “moderate naturalness position” is suggested to be most appealing, not suffering from the disquietudes of the extreme pro- and anti-naturalness positions. (shrink)

I develop an account of naturalness in physics which demonstrates that naturalness assumptions are not restricted to narrow cases in high-energy physics but are a ubiquitous part of how interlevel relations are derived in physics. After exploring how and to what extent we might justify such assumptions on methodological grounds or through appeal to speculative future physics, I consider the apparent failure of naturalness in cosmology and in the Standard Model. I argue that any such naturalness failure threatens to undermine (...) the entire structure of our understanding of intertheoretic reduction, and so risks a much larger crisis in physics than is sometimes suggested; I briefly review some currently-popular strategies that might avoid that crisis. (shrink)

The earliest formulation of the Higgs naturalness argument has been criticized on the grounds that it relies on a particular cutoff-based regularization scheme. One response to this criticism has been to circumvent the worry by reformulating the naturalness argument in terms of a renormalized, regulator-independent parametrization. An alternative response is to deny that regulator dependence poses a problem for the naturalness argument, because nature itself furnishes a particular, physically correct regulator for any effective field theory in the form of that (...) EFT’s physical cutoff, together with an associated set of bare parameters that constitute the unique physically preferred “fundamental parameters” of the EFT. Here, I argue that both lines of defense against the initial worry about regulator dependence are flawed. I argue that reformulation of the naturalness argument in terms of renormalized parameters simply trades dependence on a particular regularization scheme for dependence on a particular renormalization scheme, and that one or another form of scheme dependence afflicts all formulations of the Higgs naturalness argument. Concerning the second response, I argue that the grounds for suspending the principle of regularization or renormalization scheme independence in favor of a physically preferred parametrization are thin; the assumption of a physically preferred parametrization, whether in the form of bare “fundamental parameters” or renormalized “physical parameters,” constitutes a theoretical idle wheel in generating the confirmed predictions of established EFTs, which are invariably scheme-independent. I highlight certain features of the alternative understanding of EFTs, and the EFT-based approach to understanding the foundations of QFT, that emerges when one abandons the assumption of a physically preferred parametrization. I explain how this understanding departs from several dogmas concerning the mathematical formulation and physical interpretation of EFTs in high-energy physics. (shrink)

Few topics in cosmology are as hotly debated as the Multiverse: for some it is untestable and hence unscientific; for others it is unavoidable and a natural extension of previous science. A third position is that it is seen to follow from other theories, but those other theories might themselves be seen as too speculative. The idea of fine-tuning has a similar status. Some of this disagreement might be due to misunderstanding, in particular the degree to which probability distributions are (...) necessary to interpret conclusions based on the Multiverse, especially with regard to the Anthropic Principle. I present undisputed facts, discuss some common misunderstandings, and investigate the role played by probability. The Multiverse is perhaps an important component necessary for interpreting cosmological and other physical parameters. (shrink)

It was recently suggested that the cosmological constant problem as viewed in a non-perturbative framework is intimately connected to the choice of time and a physical Hamiltonian. We develop this idea further by calculating the non-perturbative vacuum energy density as a function of the cosmological constant with multiple choices of time. We also include a spatial curvature of the universe and generalize this calculation beyond cosmology at a classical level. We show that vacuum energy density depends on the choice of (...) time, and in almost all time gauges, is a non-linear function of the cosmological constant. This non-linear relation is a calculation for the vacuum energy density given some arbitrary value of the cosmological constant. Hence, in this non-perturbative framework, certain conventional aspects of the cosmological constant problem do not arise. We also discuss why the conventional cosmological constant problem is not well-posed, and formulate and answer the question: “Does vacuum gravitate?”. (shrink)

Many physics parameters need to be precisely set in order for life to exist in our universe. Or so says the fine-tuning argument. That the actual values are just right for life, the argument concludes, is a fact in need of deep physical or metaphysical explanation. Perhaps, the story goes, the parameter values settings are a matter of divine design. Or perhaps they result from a selection effect given our place in the “multiverse”. However, a very different approach to the (...) problem is possible. One may argue that the fine-tuning is an artefact of theorizing: it is explicable as the precise balancing act necessary for compact, systematic representation in science. Given such an explanation and drawing on earlier work from a number of sources, this essay shows how fine-tuning is best understood as evidence for a non-governing conception of laws rather than for design or multiverse. (shrink)

No evidence of “new physics” was found so far by LHC experiments, and this situation has led some voices in the physics community to call for the abandonment of the “naturalness” criterion, while other scientists have felt the need to break a lance in its defense by claiming that, at least in some sense, it has already led to successes and therefore should not be dismissed too quickly, but rather only reflected or reshaped to fit new needs. In our paper (...) we will argue that present pro-or-contra naturalness debates miss the fundamental point that naturalness, despite contrary claims, is essentially a very hazily defined, in a sense even mythical notion which, in the course of more than four decades, has been steadily, and often not coherently, shaped by its interplay with different branches of model-building in high-energy physics and cosmology on the one side, and new incoming experimental results on the other. In our paper we will endeavor to clear up some of the physical and philosophical haze by taking a closer look back at origin of naturalness in the 1970s and 1980s, with particular attention to the early work of Kenneth Wilson. In doing this, we aim to bring to light how naturalness belongs to a long tradition of present and past physical and philosophical criteria for effectively guiding theoretical reflection and experimental practice in fundamental research. (shrink)

Naturalness, as a guiding principle for effective field theories, requires that there be no sensitive correlations between phenomena at low- and high-energy scales. This essay considers four reasons to adopt this principle: natural EFTs exhibit modest empirical success; unnatural EFTs are improbable; naturalness underwrites what Williams calls a “central dogma” of EFTs; namely, that phenomena at widely separated scales should decouple; and naturalness underwrites a non-trivial notion of emergence. I argue that the first three are not compelling reasons, whereas the (...) fourth is. (shrink)

I assess various proposals for the source of the intuition that there is something problematic about contextuality, ultimately concluding that contextuality is best thought of in terms of fine-tuning. I then argue that as with other fine-tuning problems in quantum mechanics, this behaviour can be understood as a manifestation of teleological features of physics. Finally I discuss several formal mathematical frameworks that have been used to analyse contextuality and consider how their results should be interpreted by scientific realists. In the (...) course of this discussion I obtain several new mathematical results—I demonstrate that preparation contextuality is a form of fine-tuning, I show that measurement contextuality can be explained by appeal to a global constraint forbidding closed causal loops, and I demonstrate how negative probabilities can arise from a classical ontological model together with an epistemic restriction. (shrink)