The multiverse theodicy proposes to reconcile the existence of God and evil by supposing that God created all and only the creation-worthy universes and that some universes like ours are, despite their evils, creation-worthy. Drawing on work in population ethics, this paper develops a novel challenge to the multiverse theodicy. Roughly, the challenge contends that the axiological underpinnings of the multiverse theodicy harbor a ‘mere addition paradox’: the assumption that creating creation-worthy universes would always make the world (...) better turns out to have morally repugnant consequences akin to those of the assumption that adding worthwhile lives to a population would always make the overall welfare of the population better. Further, the challenge leverages this difficulty into an argument against God’s having created all and only the creation-worthy universes, and hence against the multiverse theodicy. Responses to this challenge are considered but found wanting, largely because of commitments of the multiverse theodicy that have no analogs in population ethics. (shrink)

David Wallace argues that we should take quantum theory seriously as an account of what the world is like--which means accepting the idea that the universe is constantly branching into new universes. He presents an accessible but rigorous account of the 'Everett interpretation', the best way to make coherent sense of quantum physics.

Multiverse Views in set theory advocate the claim that there are many universes of sets, no-one of which is canonical, and have risen to prominence over the last few years. One motivating factor is that such positions are often argued to account very elegantly for technical practice. While there is much discussion of the technical aspects of these views, in this paper I analyse a radical form of Multiversism on largely philosophical grounds. Of particular importance will be an account (...) of reference on the Multiversist conception, and the relativism that it implies. I argue that analysis of this central issue in the Philosophy of Mathematics indicates that Radical Multiversism must be algebraic, and cannot be viewed as an attempt to provide an account of reference without a softening of the position. (shrink)

We review different conceptions of the set-theoretic multiverse and evaluate their features and strengths. In Sect. 1, we set the stage by briefly discussing the opposition between the ‘universe view’ and the ‘multiverse view’. Furthermore, we propose to classify multiverse conceptions in terms of their adherence to some form of mathematical realism. In Sect. 2, we use this classification to review four major conceptions. Finally, in Sect. 3, we focus on the distinction between actualism and potentialism with (...) regard to the universe of sets, then we discuss the Zermelian view, featuring a ‘vertical’ multiverse, and give special attention to this multiverse conception in light of the hyperuniverse programme introduced in Arrigoni and Friedman (2013). We argue that the distinctive feature of the multiverse conception chosen for the hyperuniverse programme is its utility for finding new candidates for axioms of set theory. (shrink)

In reply to the problem of evil, some suggest that God created an infinite number of universes—for example, that God created every universe that contains more good than evil. I offer two objections to these multiverse theodicies. First, I argue that, for any number of universes God creates, he could have created more, because he could have created duplicates of universes. Next, I argue that multiverse theodicies can’t adequately account for why God would create universes with pointless suffering, (...) and hence they don’t solve the problem of evil. (shrink)

If the laws of nature are fine-tuned for life, can we infer other universes with different laws? How could we even test such a theory without empirical access to those distant places? Can we believe in the multiverse of the Everett interpretation of quantum theory or in the reality of other possible worlds, as advocated by philosopher David Lewis? At the intersection of physics and philosophy of science, this book outlines the philosophical challenge to theoretical physics in a measured, (...) well-grounded manner. The origin of multiverse theories are explored within the context of the fine-tuning problem and a systematic comparison between the various different multiverse models are included. Cosmologists, high energy physicists, and philosophers including graduate students and researchers will find a systematic exploration of such questions in this important book. (shrink)

I provide the account of divine creation found in multiverse theorists Donald Turner, Klaas Kraay, and Tim O’Connor. I show that the accounts Kraay and Turner offer are incoherent. God does not survey all possible worlds and necessarily actualize those universes in the (on balance) good worlds or the worthy worlds. If God necessarily actualizes the multiverse, we have no idea which universes are parts of that multiverse. I show next that Tim O’Connor’s multiverse account of (...) creation is also incoherent. I argue that a preferable multiverse would include a much greater variety of universes than are included in Turner, Kraay or O’Connor. In the last section I offer some concluding remarks. (shrink)

A multiverse is comprised of many universes, which quickly leads to the question: How many universes? There are either finitely many or infinitely many universes. The purpose of this paper is to discuss two conceptions of infinite number and their relationship to multiverses. The first conception is the standard Cantorian view. But recent work has suggested a second conception of infinite number, on which infinite numbers behave very much like finite numbers. I will argue that that this second conception (...) of infinite number is the correct one, and analyze what this means for multiverses. (shrink)

In this article, I develop a novel version of the multiverse theory of sets called hierarchical pluralism by introducing the notion of “degrees of intentionality” of theories. The presented view is articulated for the purpose of reconciling epistemological realism and the multiverse theory of sets so as to preserve a considerable amount of epistemic objectivity when working with the multiverse theory. I give some arguments in favor of a hierarchical picture of the multiverse in which theories (...) or models are thought to be ordered with respect to their plausibility as a manifestation of endorsing the idea that some set theories are more plausible than others. The proposed multiverse account settles the pluralist’s dilemma, the dichotomy that there is a trade-off between the richness of mathematical ontology and the objectivity of mathematical truth. The view also extends and serves as an alternative position to Balaguer’s intention-based Platonism, from which he claims that a certain version of mathematical pluralism follows. (shrink)

We review different conceptions of the set-theoretic multiverse and evaluate their features and strengths. In Sect. 1, we set the stage by briefly discussing the opposition between the ‘universe view’ and the ‘multiverse view’. Furthermore, we propose to classify multiverse conceptions in terms of their adherence to some form of mathematical realism. In Sect. 2, we use this classification to review four major conceptions. Finally, in Sect. 3, we focus on the distinction between actualism and potentialism with (...) regard to the universe of sets, then we discuss the Zermelian view, featuring a ‘vertical’ multiverse, and give special attention to this multiverse conception in light of the hyperuniverse programme introduced in Arrigoni-Friedman :77–96, 2013). We argue that the distinctive feature of the multiverse conception chosen for the hyperuniverse programme is its utility for finding new candidates for axioms of set theory. (shrink)

The multiverse view in set theory, introduced and argued for in this article, is the view that there are many distinct concepts of set, each instantiated in a corresponding set-theoretic universe. The universe view, in contrast, asserts that there is an absolute background set concept, with a corresponding absolute set-theoretic universe in which every set-theoretic question has a definite answer. The multiverse position, I argue, explains our experience with the enormous range of set-theoretic possibilities, a phenomenon that challenges (...) the universe view. In particular, I argue that the continuum hypothesis is settled on the multiverse view by our extensive knowledge about how it behaves in the multiverse, and as a result it can no longer be settled in the manner formerly hoped for. (shrink)

Recent advances in string theory and inflationary cosmology have led to a surge of interest in the possible existence of an ensemble of cosmic regions, or “universes”, among the members of which key physical parameters, such as the masses of elementary particles and the coupling constants, might assume different values. The observed values in our cosmic region are then attributed to an observer selection effect (the so-called anthropic principle). The assemblage of universes has been dubbed “the multiverse”. In this (...) paper we review the multiverse concept and the criticisms that have been advanced against it on both scientific and philosophical grounds. (shrink)

In this article we analyze the method of forcing from a more philosophical perspective. After a brief presentation of this technique we outline some of its philosophical imports in connection with realism. We shall discuss some philosophical reactions to the invention of forcing, concentrating on Mostowski’s proposal of sharpening the notion of generic set. Then we will provide an overview of the notions of multiverse and the related philosophical debate on the foundations of set theory. In conclusion, we connect (...) this modern debate and Mostowski’s proposal, suggesting a way to analyze the notion of genericity within the framework of a multiverse structure. (shrink)

Given recent scientific findings suggesting that our world is part of a multiverse, Leland Harper argues that we ought to abandon the idea of an active God in Judeo-Christian theism. This shift results in a more coherent, cohesive and, ultimately, better account of God than is currently offered by the Judeo-Christian monotheistic tradition.

The intended title was “Universe Oriented Ontology” or “Multiverse Oriented Ontology”, or “Universe or Multiverse Metaphysics”. I mention this as it gives an idea about the meaning and intention of the title and the work as well as the titles I considered and why I moved away from them to the present one. The sub-title provides a further hint towards the intentions of the work, namely: ” Beyond Earth- and Human-centricity’. I opted for ‘transcending’ rather than beyond, as (...) I am still in the process of describing the process of transcending and many of the ideas I am obliged to use from our conceptual system and practices are still earth- and anthropo-centered, And, they have not yet gone to a state beyond those two -isms. I say something about universe-centeredness, then about planet earth as point and frame of reference and anthropo-centricity. The socio-cultural practice of philosophy and the doing of philosophy is merely one of many human, social and cultural practices. I post different notions of philosophy by a number of writers, some of them philosophers. These notions are about their perceptions of what philosophy is. Few of them go into detail about the subject-matter of philosophy. No one really deal with the aims, purposes and objectives of the discipline and none deal with the nature of the doing of philosophy or philosophizing. Activities that I suggest resemble certain features of the processes of theorizing. I end with explorations of possible characteristics of original- and creative thinkers. I do this by mentioning a number of themes of meta-philosophy listed and described by Peter Suber. I make a number of comments in them and highlight aspects relevant to these type of thinkers. One find them of course in all disciplines and socio-cultural [racticesand disciplines be they the arts,humanities, sciences, etc. I am of course specifically concerned with original andcreative thinkers inthe Western tradition of philosophy. As I am a radical and absolute sceptic, I end with an article on this theme. It is said by everyone, for example Hume, Russell and Pascal, that such a radical position is psychologically impossible and that it cannot be lived 24/7. Pascal for example opted for believe or faith and he and a number of writers suggest that that is the only way out and the final position of radical sceptics. I disagree with him. (shrink)

As a candidate theory of quantum gravity, the popularity of string theory has waxed and waned over the past four decades. One current source of scepticism is that the theory can be used to derive, depending upon the input geometrical assumptions that one makes, a vast range of different quantum field theories, giving rise to the so-called landscape problem. One apparent way to address the landscape problem is to posit the existence of a multiverse; this, however, has in turn (...) drawn heightened attention to questions regarding the empirical testability and predictivity of string theory. We argue first that the landscape problem relies on dubious assumptions and does not motivate a multiverse hypothesis. Nevertheless, we then show that the multiverse hypothesis is scientifically legitimate and could be coupled to string theory for other empirical reasons. Looking at various cosmological approaches, we offer an empirical criterion to assess the scientific status of multiverse hypotheses. (shrink)

Recent developments in cosmology and particle physics have led to speculation that our universe is merely one of a multitude of universes. While this notion, the multiverse hypothesis, is highly contested as legitimate science, it has nonetheless struck many physicists as a necessary consequence of the effort to construct a final, unified theory. In Process and Reality (1929), his magnum opus, Alfred North Whitehead advanced a cosmology as part of his general metaphysics of process. Part of this project involved (...) a theory of cosmic epochs which bears a remarkable affinity to current cosmological speculation. This paper demonstrates how the basic framework of a multiverse theory is already present in Whitehead’s cosmology and defends the necessity of speculation in the quest for an explanatory description. (shrink)

Multiverses are predictions based on theories. Focusing on each theory’s assumptions is key to evaluating a proposed multiverse. Although accepted theories of particle physics and cosmology contain non-intuitive features, multiverse theories entertain a host of “strange” assumptions classified as metaphysical topics such as: infinity, duplicate yous, hypothetical fields, more than three space dimensions, Hilbert space, advanced civilizations, and reality established by mathematical relationships. It is easy to confuse multiverse proposals because many divergent models exist. This overview defines (...) the characteristics of eleven popular multiverse proposals. The characteristics compared are: initial conditions, values of constants, laws of nature, number of space dimensions, number of universes, and fine tuning explanations. Future scientific experiments may validate selected assumptions; but until they do, proposals by philosophers may be as valid as theoretical scientific theories. (shrink)

Multiverses are predictions based on theories. Focusing on each theory’s assumptions is key to evaluating a proposed multiverse. Although accepted theories of particle physics and cosmology contain non-intuitive features, multiverse theories entertain a host of “strange” assumptions classified as metaphysical topics such as: infinity, duplicate yous, hypothetical fields, more than three space dimensions, Hilbert space, advanced civilizations, and reality established by mathematical relationships. It is easy to confuse multiverse proposals because many divergent models exist. This overview defines (...) the characteristics of eleven popular multiverse proposals. The characteristics compared are: initial conditions, values of constants, laws of nature, number of space dimensions, number of universes, and fine tuning explanations. Future scientific experiments may validate selected assumptions; but until they do, proposals by philosophers may be as valid as theoretical scientific theories. (shrink)

From a physical point of view, the no-boundary Hartle-Hawking model put forward in 1983 was an attempt to demonstrate that the incorporation of quantum effects into the general theory of relativity would solve the problem of singularities that make the theory of relativity incomplete. This was achieved by imposing the so called “no-boundary conditions” whereby the Universe could emerge with non-zero probability from a non-existing state. Stephen Hawking quickly turned this result into a metaphysical claim that physical laws explained away (...) the necessity of the Divine intervention at the origin of the Universe. This paper offers an inquiry into the line of arguments presented by Hawking and Mlodinow in their book The Grand Design and supported with the claim that the yet unknown versionof the superstring theory, the M-theory, is an ultimate theory of the Universe. The upshot of the paper is that although the argument in the Grand Design relies on the newer achievements of physics embedded in the controversial multi-verse setting, it does not escape the question of the origin of the most general laws of physics that bring the Universe into existence. (shrink)

The multiverse hypothesis is one of the leading proposed explanations of cosmic fine-tuning for life. One common objection to the multiverse hypothesis is that, even if it were true, it would not explain why this universe, our universe, is fine-tuned for life. To think it would so explain is allegedly to commit “the inverse gambler's fallacy.” This paper presents what the inverse gambler's fallacy is supposed to be, then surveys the discussion of it in the philosophical literature of (...) the last 35 years. (shrink)

We argue that Kraay's "theistic multiverse" response to the objections to theism [Kraay 2011] is unsuccessful as it simply shifts the problems leveled against theism from the level of possible worlds to the level of possible universes. Furthermore, when we restate the objections at the level of possible universes, we can show how Kraay's conclusion about the uniqueness of the theistic multiverse is undermined.

A debated issue in the mathematical foundations in at least the last two decades is whether one can plausibly argue for the merits of treating undecidable questions of mathematics, e.g., the Continuum Hypothesis, by relying on the existence of a plurality of set-theoretical universes except for a single one, i.e., the well-known set-theoretical universe V associated with the cumulative hierarchy of sets. The multiverse approach has some varying versions of the general concept of multiverse yet my intention is (...) to primarily address ontological multiversism as advocated, for instance, by Hamkins or Väätänen, precisely for the reason that they proclaim, to the one or the other extent, ontological preoccupations for the introduction of respective multiverse theories. Taking also into account Woodin’s and Steel’s multiverse versions, I take up an argumentation against multiversism, and in a certain sense against platonism in mathematical foundations, mainly on subjectively founded grounds, while keeping an eye on Clarke-Doane’s concern with Benacerraf’s challenge. I note that even though the paper is rather technically constructed in arguing against multiversism, the non-negligible philosophical part is influenced to a certain extent by a phenomenologically motivated view of the matter. (shrink)

Some analytic philosophers of religion argue that theists should embrace the hypothesis of the multiverse to address the problem of evil and make the concept of a “best possible creation” plausible. I discuss what classical theists, such as Augustine, Anselm, and Aquinas, might make of the multiverse hypothesis including issues such as: the principle of plenitude, what a classical theist multiverse could look like, and how a classical theist multiverse could deal with the problem of evil (...) and the question of a best possible creation. (shrink)

The objective of this paper is analyzing to which extent the multiverse hypothesis provides a real explanation of the peculiarities of the laws and constants in our universe. First we argue in favor of the thesis that all multiverses except Tegmark’s “mathematical multiverse” are too small to explain the fine tuning, so that they merely shift the problem up one level. But the “mathematical multiverse" is surely too large. To prove this assessment, we have performed a number (...) of experiments with cellular automata of complex behavior, which can be considered as universes in the mathematical multiverse. The analogy between what happens in some automata (in particular Conway’s “Game of Life") and the real world is very strong. But if the results of our experiments can be extrapolated to our universe, we should expect to inhabit—in the context of the multiverse—a world in which at least some of the laws and constants of nature should show a certain time dependence. Actually, the probability of our existence in a world such as ours would be mathematically equal to zero. In consequence, the results presented in this paper can be considered as an inkling that the hypothesis of the multiverse, whatever its type, does not offer an adequate explanation for the peculiarities of the physical laws in our world. (shrink)

In the Marvel Cinematic Universe (MCU), according to the Ancient One, magic is created by drawing energy from the other dimensions of the multiverse. This sounds like a concept from science fiction, but the idea that people are living in a vast multiverse is very possibly science fact. A recurring and especially important theme in Doctor Strange is the role that human beings are supposed to play in the universe. The concept of the multiverse is well established (...) in the Marvel comics and has officially been introduced into the MCU, and the way it is introduced touches on central issues in the philosophy of physics. Quantum mechanics is hands‐down one of the greatest accomplishments of science. Understanding the apparent collapse of the wave function upon observation is the core of the measurement problem. There are different ways of explaining this, which are called “interpretations” of quantum mechanics. (shrink)

Cosmological models that invoke a multiverse - a collection of unobservable regions of space where conditions are very different from the region around us - are controversial, on the grounds that unobservable phenomena shouldn't play a crucial role in legitimate scientific theories. I argue that the way we evaluate multiverse models is precisely the same as the way we evaluate any other models, on the basis of abduction, Bayesian inference, and empirical success. There is no scientifically respectable way (...) to do cosmology without taking into account different possibilities for what the universe might be like outside our horizon. Multiverse theories are utterly conventionally scientific, even if evaluating them can be difficult in practice. (shrink)

I present and defend an “indexical” version of the Fine-Tuning Argument. I begin by outlining the dialectic between the Fine-Tuning Argument, the Multiverse Objection, and the This-Universe Reply. Next, I sketch an indexical fine-tuning argument and defend it from two new objections. Then, I show that such an argument is immune to the Multiverse Objection. I explain how a further augmentation to the argument allows it to avoid an objection I call the “Indifference Objection.” I conclude that my (...) indexical version of the Fine-Tuning Argument is no less cogent than the standard version, and yet it is immune to the Multiverse Objection. (shrink)

Suppose that reality consists of parallel universes of every variety imaginable. No path through space and time leads from one to another, and each universe is causally isolated from the rest. Some physicists believe a ‘multiverse’ hypothesis not terribly distant from this one simplifies quantum mechanics and provides an elegant explanation of why our universe has its particular laws. Suppose as science advances we come to accept the multiverse hypothesis, so construed.

Penelope Maddy has recently addressed the set-theoretic multiverseset-theoretic multiverse, and expressed reservations on its status and merits Foundations of mathematics. Essays in honor of W. Hugh Woodin’s 60th birthday. Contemporary mathematics. American Mathematical Society, Providence, pp. 289–322, 2017). The purpose of the paper is to examine her concerns, by using the interpretative framework of set-theoretic naturalismset-theoretic naturalism. I first distinguish three main forms of ‘multiversism’multiversism, and then I proceed to analyse MaddyMaddy’s concerns. Among other things, I take into account (...) salient aspects of multiverse-related mathematics, in particular, research programmes in set theory for which the use of the multiverse seems to be crucial, and show how one may provide responses to MaddyMaddy’s concerns based on a careful analysis of ‘multiverse practice’. (shrink)

Penelope Maddy has recently addressed the set-theoretic multiverse, and expressed reservations on its status and merits ([Maddy, 2017]). The purpose of the paper is to examine her concerns, by using the interpretative framework of set-theoretic naturalism. I first distinguish three main forms of 'multiversism', and then I proceed to analyse Maddy's concerns. Among other things, I take into account salient aspects of multiverse-related mathematics , in particular, research programmes in set theory for which the use of the (...) class='Hi'>multiverse seems to be crucial, and show how one may provide responses to Maddy's concerns based on a careful analysis of 'multiverse practice'. (shrink)

In a recent paper in this journal, Jason Megill (2011) offers an innovative meta-argument which deploys considerations about multiple universes in an effort to block all arguments from evil. In what follows, I contend that Megill has failed to establish a key premise in his meta-argument. I also offer a rival account of the effect of multiverse models on the debate about evil.

The multiverse hypothesis is growing in popularity among theistic philosophers because some view it as the preferable way to solve certain difficulties presented by theistic belief. In this paper, I am concerned specifically with its application to Rowe’s problem of no best world, which suggests that God’s existence is impossible given the fact that the world God actualizes must be unsurpassable, yet for any given possible world, there is one greater. I will argue that, as a solution to the (...) problem of no best world, the multiverse hypothesis fails. To defend my thesis, I will first define the multiverse hypothesis and articulate the problem of no best world and how the multiverse hypothesis is thought to solve it. I will then show that the solution fails by articulating two problems that have been mentioned, but not developed, in the literature—what I call the problem of no highest standard and the problem of multiverse cardinality. In each case, after articulating the problem, I will offer possible responses to the problem and show why those responses are inadequate. (shrink)

One might suppose that Everettian quantum mechanics (EQM) is inhospitable to metaphysial indeterminacy (MI), given that, as A. Wilson (2020) puts it, "the central idea of EQM is to replace indeterminacy with multiplicity" (77). But as Wilson goes on to suggest, the popular decoherence-based understanding of EQM (henceforth: DEQM) appears to admit of indeterminacy in both world number and world nature, where the latter indeterminacy---our focus here---is plausibly metaphysical. After a brief presentation of DEQM (S1), we bolster the case for (...) there being MI in world nature in DEQM (S2). The remainder of the paper is devoted to a comparative assessment of the two main approaches to MI for purposes of accommodating this MI---namely, a metaphysical supervaluationist approach (as per Barnes and Williams 2011) and a determinable-based approach (as per Wilson 2013 and Calosi and Wilson 2018 and 2021). We briefly describe each approach (S3), then offer arguments in favour of a determinable-based approach to world nature MI in DEQM (S4). (shrink)

Finetuning and Naturalness are extra-empirical theory assessments that reflect our expectation how scientific theories should provide an intuitive understanding about the foundations underlying the observed phenomena. Recently, the absence of new physics at the LHC and the theoretical evidence for a multiverse of alternative physical realities, predicted by our best fundamental theories, have casted doubts about the validity of these concepts. In this essay we argue that the discussion about Finetuning should not predominantly concentrate on the desired features a (...) fundamental theory is expected to have, but rather on the question what a theory needs to qualify as fundamental in the first place. By arguing that a fundamental description of the Universe should possess zero entropy, we develop a ‘holistic’ concept for the most fundamental layer of reality: The fundamental description of the Universe is the Universe itself, understood as an entangled quantum state. Adopting a universal applicability of quantum mechanics, in this framework the behavior of subsystems can be understood as the perspectival experience of an entangled quantum Universe perceived through the “lens of decoherence”. In this picture the fundamental reality is non-local, and finetuned coincidences in effective theories may be understood in a way similar to EPR-correlations. This notion provides a fresh view on the topic of Naturalness and Finetuning since it suggests that Finetuning problems and hints for anthropic explanations are an artifact of theories building up on subsystems rather than on the fundamental description. Recent work in quantum gravity aiming at an understanding of spacetime geometry from entanglement entropy could be interpreted as a first sign of such a paradigm shift. (shrink)

In recent decades, scientific theories have postulated the existence of many universes beyond our own. The details and implications of these theories are hotly contested. Some philosophers argue that these scientific models count against the existence of God. Others, however, argue that if God exists, a multiverse is precisely what we should expect to find. Moreover, these philosophers claim that the idea of a divinely created multiverse can help believers in God respond to certain arguments for atheism. These (...) proposals are, of course, also extremely controversial. This volume collects together twelve newly published essays – two by physicists, and ten by philosophers – that discuss various aspects of this issue. Some of the essays support the idea of a divinely created multiverse; others oppose it. Scientific, philosophical, and theological issues are considered. (shrink)

In this paper, an evolutionary multiverse argument against naturalism (EMAAN) is presented: E1. In an evolutionary multiverse, phenomena have variable evolutionary ages. E2. After some time T, the development of the empirical sciences will be evolutionarily conserved. E3. The phenomena with an evolutionary age above T are methodologically supernatural. Entities are classified according to whether they are (1) physical and spatiotemporal, (2) causally efficacious, and (3) either observed by or explanatorily necessary for the empirical sciences. While the conjunction (...) of (1) and (2) is taken to be sufficient for existence in reality, the negation of (3) defines methodological supernaturalness. EMAAN uses a generalization of evolutionary theory, namely cosmological natural selection, to argue that phenomena evolve that fulfill conditions (1) and (2), but not (3). This shows that methodologically supernatural phenomena have a clear epistemology according to a theory that is grounded in the commitments of naturalism. Supernatural phenomena are not observed by the empirical sciences because the empirical sciences themselves are supernaturally guided and predestined to develop according to an evolutionarily conserved plan. In spite of this scientific plan, there is room for afterlives and supernaturality in the everyday experience. (shrink)

Timothy O’Connor and Philip Woodward defend a version of a compositional theory, according to which an incarnate deity has two natures, each of which is a distinct component of its being. They then extend this model to permit multiple incarnations. Finally, they consider an objection to this model based on the theological idea that Christ’s work is necessary for ushering in a united community of all divine-image-bearing creatures. In response, they speculate that no such all-encompassing community would be possible, given (...) the vast differences between such creatures. Accordingly, they speculate that each incarnation could help to bring about a unified community of the relevant sort of divine-image-bearing creatures, and that each of these communities would, in its own way, participate in the common goal of union with God. (shrink)

In the absence of a fundamental theory that precisely predicts values for observable parameters, anthropic reasoning attempts to constrain probability distributions over those parameters in order to facilitate the extraction of testable predictions. The utility of this approach has been vigorously debated of late, particularly in light of theories that claim we live in a multiverse, where parameters may take differing values in regions lying outside our observable horizon. Within this cosmological framework, we investigate the efficacy of top-down anthropic (...) reasoning based on the weak anthropic principle. We argue contrary to recent claims that it is not clear one can either dispense with notions of typicality altogether or presume typicality, in comparing resulting probability distributions with observations. We show in a concrete, top-down setting related to dark matter, that assumptions about typicality can dramatically affect predictions, thereby providing a guide to how errors in reasoning regarding typicality translate to errors in the assessment of predictive power. We conjecture that this dependence on typicality is an integral feature of anthropic reasoning in broader cosmological contexts, and argue in favour of the explicit inclusion of measures of typicality in schemes invoking anthropic reasoning, with a view to extracting predictions from multiverse scenarios. (shrink)

Anthropic arguments in multiverse cosmology and string theory rely on the weak anthropic principle (WAP). We show that the principle, though ultimately a tautology, is nevertheless ambiguous. It can be reformulated in one of two unambiguous ways, which we refer to as WAP_1 and WAP_2. We show that WAP_2, the version most commonly used in anthropic reasoning, makes no physical predictions unless supplemented by a further assumption of "typicality", and we argue that this assumption is both misguided and unjustified. (...) WAP_1, however, requires no such supplementation; it directly implies that any theory that assigns a non-zero probability to our universe predicts that we will observe our universe with probability one. We argue, therefore, that WAP_1 is preferable, and note that it has the benefit of avoiding the inductive overreach characteristic of much anthropic reasoning. (shrink)

I present and defend an “indexical” version of the Fine-Tuning Argument. I begin by outlining the dialectic between the Fine-Tuning Argument, the Multiverse Objection, and the This-Universe Reply. Next, I sketch an indexical fine-tuning argument and defend it from two new objections. Then, I show that such an argument is immune to the Multiverse Objection. I explain how a further augmentation to the argument allows it to avoid an objection I call the “Indifference Objection.” I conclude that my (...) indexical version of the Fine-Tuning Argument is no less cogent than the standard version, and yet it is immune to the Multiverse Objection. (shrink)

In this paper I apply the concept of _inter-Model Inconsistency in Set Theory_ (MIST), introduced by Carolin Antos (this volume), to select positions in the current universe-multiverse debate in philosophy of set theory: I reinterpret H. Woodin’s _Ultimate L_, J. D. Hamkins’ multiverse, S.-D. Friedman’s hyperuniverse and the algebraic multiverse as normative strategies to deal with the situation of de facto inconsistency toleration in set theory as described by MIST. In particular, my aim is to situate these (...) positions on the spectrum from inconsistency avoidance to inconsistency toleration. By doing so, I connect a debate in philosophy of set theory with a debate in philosophy of science about the role of inconsistencies in the natural sciences. While there are important differences, like the lack of threatening explosive inferences, I show how specific philosophical positions in the philosophy of set theory can be interpreted as reactions to a state of inconsistency similar to analogous reactions studied in the philosophy of science literature. My hope is that this transfer operation from philosophy of science to mathematics sheds a new light on the current discussion in philosophy of set theory; and that it can help to bring philosophy of mathematics and philosophy of science closer together. (shrink)

The multiverse is a hypothesis for which there is no evidence, and perhaps can never be any evidence. It is only since 1998 that it has leapt off the blackboards of a few physicists doing esoteric mathematics and lodged itself in the popular imagination. As is the way with popular science, it is easy to move from speculating that there might have been more than one big bang to proceeding on the basis that there has been more than one (...) big bang. (shrink)

In extracting predictions from theories that describe a multiverse, we face the difficulty that we must assess probability distributions over possible observations, prescribed not just by an underlying theory, but by a theory together with a conditionalization scheme that allows for selection effects. This means we usually need to compare distributions that are consistent with a broad range of possible observations, with actual experimental data. One controversial means of making this comparison is by invoking the 'principle of mediocrity': that (...) is, the principle that we are typical of the reference class implicit in the conjunction of the theory and the conditionalization scheme. In this paper, I quantitatively assess the principle of mediocrity in a range of cosmological settings, employing 'xerographic distributions' to impose a variety of assumptions regarding typicality. I find that for a fixed theory, the assumption that we are typical gives rise to higher likelihoods for our observations. If, however, one allows both the underlying theory and the assumption of typicality to vary, then the assumption of typicality does not always provide the highest likelihoods. Interpreted from a Bayesian perspective, these results support the claim that when one has the freedom to consider different combinations of theories and xerographic distributions, one should favor the framework that has the highest posterior probability; and then from this framework one can infer, in particular, how typical we are. In this way, the invocation of the principle of mediocrity is more questionable than has been recently claimed. (shrink)