We develop and apply a multi-dimensional conception of explanatory depth towards a comparative analysis of inflationary and bouncing paradigms in primordial cosmology. Our analysis builds on earlier work due to Azhar and Loeb (2021) that establishes initial condition fine-tuning as a dimension of explanatory depth relevant to debates in contemporary cosmology. We propose dynamical fine-tuning and autonomy as two further dimensions of depth in the context of problems with instability and trans-Planckian modes that afflict bouncing and inflationary approaches respectively. In (...) the context of the latter issue, we argue that the recently formulated trans-Planckian censorship conjecture leads to a trade-off for inflationary models between dynamical fine-tuning and autonomy. We conclude with the suggestion that explanatory preference with regard to the different dimensions of depth is best understood in terms of differing attitudes towards heuristics for future model building. (shrink)

This essay proposes a comprehensive blueprint for the hylomorphic foundations of cosmology. The key philosophical explananda in cosmology are those dealing with global processes and structures, the regularity of global regularities, and the existence of the global as such. The possibility of elucidating these using alternatives to hylomorphism is outlined and difficulties with these alternatives are raised. Hylomorphism, by contrast, provides a sound philosophical ground for cosmology insofar as it leads to notions of cosmic essence, the unity of complex essences, (...) and globally emergent properties. These are used as the basis to account for the aforementioned cosmological explananda and to resolve two problems in the philosophy of cosmology: the meta-law dilemma and the uniqueness of the universe. In summary, cosmology needs hylomorphism because it is able to ground cosmology’s efforts as a scientific inquiry. It can do so because hylomorphism philosophically accounts for changing substances and aggregates of substances, the various scales of law-governed behavior measured by the natures of those substances, and how those substances as parts relate to the universe as a whole. (shrink)

This essay proposes a comprehensive blueprint for the hylomorphic foundations of cosmology. The key philosophical explananda in cosmology are those dealing with global processes and structures, the regularity of global regularities, and the existence of the global as such. The possibility of elucidating these using alternatives to hylomorphism is outlined and difficulties with these alternatives are raised. Hylomorphism, by contrast, provides a sound philosophical ground for cosmology insofar as it leads to notions of cosmic essence, the unity of complex essences, (...) and globally emergent properties. These are used as the basis to account for the aforementioned cosmological explananda and to resolve two problems in the philosophy of cosmology: the meta-law dilemma and the uniqueness of the universe. In summary, cosmology needs hylomorphism because it is able to ground cosmology’s efforts as a scientific inquiry. It can do so because hylomorphism philosophically accounts for changing substances and aggregates of substances, the various scales of law-governed behavior measured by the natures of those substances, and how those substances as parts relate to the universe as a whole. (shrink)

In his Critique of Pure Reason, in the chapter on the antinomy of pure reason, Kant not only argues that aprioristic cosmology is doomed to failure; he also implies that empirical knowledge about the universe is impossible. Today, such a negative verdict about the possibility of cosmological knowledge seems implausible because physical cosmology has made substantial progress. In particular, the spatiotemporal extension of the universe now seems a matter of empirical investigation in which models figure centrally. But I think it (...) is worth considering the possibility that Kant got something right and that he offers insights that can help us to better understand problems in present-day cosmology. In this article, I explore a striking coincidence: according to both Kant and current wisdom, cosmology faces a serious underdetermination problem regarding the spatiotemporal extension of the world. As a closer analysis reveals, however, Kant and modern cosmology differ on the reasons why underdetermination arises. In current cosmology, underdetermination follows from laws that are knowable a posteriori, and not only from the very idea of cosmological knowledge, as Kant would have it. This suggests that the current underdetermination problem is not fully a Kantian one. (shrink)

En física, el infinito aparece vinculado al problema de lo continuo de las representaciones matemáticas usadas por las diversas teorías y, por lo tanto, a la posibilidad de la infinita divisibilidad y de la infinita extensión de la geometría del espaciotiempo y de los conceptos y magnitudes físicas mensurables. El modelo estándar de las partículas considera que las partículas elementales son «infinitamente» pequeñas, donde surgen cálculos con resultados infinitos para determinadas cantidades físicas y, para eliminarlos, se utilizan métodos de renormalización, (...) usados también en la cosmología clásica y en el modelo estándar cosmológico del Big Bang con la finalidad de domesticar los infinitos. La investigación en gravedad cuántica considera que el espacio no sea infinitamente divisible y los modelos de multiversos suponen tiempos y espacios infinitos para el Universo. Siendo nuestras teorías siempre limitadas y perfectibles, parece que no podemos probar, en física, que el Universo sea físicamente infinito. (shrink)

Modern scientific cosmology pushes the boundaries of knowledge and the knowable. This is prompting questions on the nature of scientific knowledge. A central issue is what defines a 'good' model. When addressing global properties of the Universe or its initial state this becomes a particularly pressing issue. How to assess the probability of the Universe as a whole is empirically ambiguous, since we can examine only part of a single realisation of the system under investigation: at some point, data will (...) run out. We review the basics of applying Bayesian statistical explanation to the Universe as a whole. We argue that a conventional Bayesian approach to model inference generally fails in such circumstances, and cannot resolve, e.g., the so-called 'measure problem' in inflationary cosmology. Implicit and non-empirical valuations inevitably enter model assessment in these cases. This undermines the possibility to perform Bayesian model comparison. One must therefore either stay silent, or pursue a more general form of systematic and rational model assessment. We outline a generalised axiological Bayesian model inference framework, based on mathematical lattices. This extends inference based on empirical data (evidence) to additionally consider the properties of model structure (elegance) and model possibility space (beneficence). We propose this as a natural and theoretically well-motivated framework for introducing an explicit, rational approach to theoretical model prejudice and inference beyond data. (shrink)

We develop and apply a multi-dimensional account of explanatory depth towards a comparative analysis of inflationary and bouncing paradigms in primordial cosmology. Our analysis builds on earlier work due to Azhar and Loeb (2021) that establishes initial conditions fine-tuning as a dimension of explanatory depth relevant to debates in contemporary cosmology. We propose dynamical fine-tuning and autonomy as two further dimensions of depth in the context of problems with instability and trans-Planckian modes that afflict bouncing and inflationary approaches respectively. In (...) the context of the latter issue, we argue that the recently formulated trans-Planckian censorship conjecture leads to a trade-off for inflationary models between dynamical fine-tuning and autonomy. We conclude with the suggestion that explanatory preference with regard to the different dimensions of depth is best understood in terms of differing attitudes towards heuristics for future model building. (shrink)

The paper addresses a question concerning George Ellis’s theory of top-down causation by considering a challenge to the “level-picture of nature” which he employs as a foundational element in his theory. According to the level-picture, nature is ordered by distinct and finitely many levels, each characterised by its own types of entities, relations, laws and principles of behavior, and causal relations to their respective neighbouring top- and bottom-level. The branching hierarchy that results from this picture enables Ellis to build his (...) model of modular hierarchical structure for complexity, his account of same-level, bottom-up and top-down causation, of emergence, equivalence-classes and multiple realisability. The three main arguments for the level-picture in Ellis’s works are reconstructed and shown to face serious problems. Finally, the paper presents a possible solution to this challenge by introducing a reformulation of certain fundamental points of Ellis’s theory that does without the level-picture of nature. This allows us to preserve all of his central claims about the model of complexity, the three types of causation, emergence, equivalence-classes and multiple realisability. Any problems pertaining to the level-picture can be remedied in the context of Ellis’s theory of top-down causation. (shrink)

This study is based on the many cosmological problems in Islam as aspects of thought that receive serious attention. In fact, there are also many polemics of thought that occur amongst Muslim scholars, which can be divided into two main groups: traditionalists and rationalists. The traditionalists, represented by Al-Ghazali and the Ash'ariyah theologians, put forward their cosmological thinking on the principle of God's absolute will, while the rationalists, especially those represented by Avicenna, proposed their cosmological thinking based on the theory (...) of emanation from Plotinus in terms of its creation and the concept of a geocentric Ptolameus in terms of its structure. In this conflict of thought between the two groups, Averroes proposed a cosmological thought different from the two. This study seeks to elaborate on the thought of Ibn Rushd's cosmology which is different from that of Ibn Sina and Al-Ghazali.CONTRIBUTION: This research provides a clear understanding of the cosmological thoughts put forward by earlier Muslim thinkers. In particular, it wants to bridge the differences regarding the concept of cosmology as put forward by Ibn Sina and Al-Ghazali and how Ibn Rushd bridges the two. (shrink)

Modern scientific cosmology pushes the boundaries of knowledge and the knowable. This is prompting questions on the nature of scientific knowledge, and the emergence of the new field “Philosophy of Cosmology.” One central issue is what defines a “good” model. I discuss how “good” models are conventionally chosen, and how those methods operate in data-sparse situations: enabling the implicit introduction of value judgments, which can determine inference and lead to inferential polarization, e.g., on the question of ultimate explanation. Additional dimensions (...) for comparing models are needed. A three-legged comparison is proposed: evidence, elegance and beneficence. This explicitly considers the categories of criteria that are always at least implicitly used. A tentative path to an implementation of the proposed model comparison framework is presented. This extends the Bayesian statistical framework. Model comparison methodology is fertile ground for dialogue between the sciences and the humanities. The proposed framework might facilitate such a dialogue. (shrink)

By the end of the twentieth century, many prominent cosmologists were fascinated by the questions why is the universe the way it is, and why does the universe appear to be just right for life to emerge.1 Indeed, the shift to posing questions beginning with why rather than what or how is a relatively recent development in modern cosmology. This paper begins by looking at the emergence of why questions in cosmological discourse by tracing affiliated anthropic reasoning and fine-tuning arguments (...) in cosmology. I also consider recent suggestions that the laws of physics may themselves evolve. In response to the why questions, this paper then examines the proliferation of multiverse discourse in the late twentieth... (shrink)

La tesis de la subdeterminación empírica representa uno de los mayores desafíos contemporáneos en contra del realismo científico, sin embargo, frecuentemente se le ha considerado como un reto coherente y se ha buscado una forma de atenuar su impacto ya sea mitigando alguna posición realista, o bien, atacando alguno de sus presupuestos más problemáticos. En este ensayo defiendo un argumento en su contra, a saber, que es una tesis que nos conduce a una reductio y que semejante resultado echa por (...) tierra su supuesta plausibilidad como una tesis antirrealista. (shrink)

The concept of the universe is used in physical cosmology differently from the usual meaning of the term, naively considered as the entire reality. Traditionally, thinking about the whole led to logical contradictions. Taking as reference the Kantian antecedent, different contemporary philosophical notions of the universe are analysed in the first part of this paper, including realist and constructivist approaches, as well as a notion of the universe as a physical object. In the second part, the specific notion from the (...) standard physical cosmology is discussed. Although modelling the universe as a physical system provides a specific way to define some global properties, the universe as a whole remains empirically inaccessible. Hence, the discussion about the under-determined global properties depends ultimately on philosophical preferences. Under these circumstances, it is argued that the realist interpretation of such properties becomes problematic because it leads to unstable conclusions. Finally, it is argued that the notion of the universe as conceived in standard cosmology is not necessarily consistent with an approach that considers it to be a physical object. (shrink)

The causal closure of physics is usually discussed in a context free way. Here I discuss it in the context of engineering systems and biology, where strong emergence takes place due to a combination of upwards emergence and downwards causation. Firstly, I show that causal closure is strictly limited in terms of spatial interactions because these are cases that are of necessity strongly interacting with the environment. Effective Spatial Closure holds ceteris parabus, and can be violated by Black Swan Events. (...) Secondly, I show that causal closure in the hierarchy of emergence is a strictly interlevel affair, and in the cases of engineering and biology encompasses all levels from the social level to the particle physics level. However Effective Causal Closure can usefully be defined for a restricted set of levels, and one can experimentally determine Effective Theories that hold at each level. This does not however imply those effective theories are causally complete by themselves. In particular, the particle physics level is not causally complete by itself in the contexts of solid state physics, digital computers, or biology. Furthermore Inextricably Intertwined Levels occur in all these contexts. (shrink)

I offer an explicit account of the underdetermination thesis as well as of the many challenges it poses to scientific realism; a way to answer to these challenges is explored and outlined, by shifting attention to the content of theories. I argue that, even if we have solid grounds (as I contend we do) to support that some varieties of the underdetermination thesis are true, scientific realism can still offer an adequate picture of the aims and achievements of science.

Cosmology raises novel philosophical questions regarding the use of probabilities in inference. This work aims at identifying and assessing lines of arguments and problematic principles in probabilistic reasoning in cosmology. -/- The first, second, and third papers deal with the intersection of two distinct problems: accounting for selection effects, and representing ignorance or indifference in probabilistic inferences. These two problems meet in the cosmology literature when anthropic considerations are used to predict cosmological parameters by conditionalizing the distribution of, e.g., the (...) cosmological constant on the number of observers it allows for. However, uniform probability distributions usually appealed to in such arguments are an inadequate representation of indifference, and lead to unfounded predictions. It has been argued that this inability to represent ignorance is a fundamental flaw of any inductive framework using additive measures. In the first paper, I examine how imprecise probabilities fare as an inductive framework and avoid such unwarranted inferences. In the second paper, I detail how this framework allows us to successfully avoid the conclusions of Doomsday arguments in a way no Bayesian approach that represents credal states by single credence functions could. -/- There are in the cosmology literature several kinds of arguments referring to self- locating uncertainty. In the multiverse framework, different "pocket-universes" may have different fundamental physical parameters. We don’t know if we are typical observers and if we can safely assume that the physical laws we draw from our observations hold elsewhere. The third paper examines the validity of the appeal to the "Sleeping Beauty problem" and assesses the nature and role of typicality assumptions often endorsed to handle such questions. -/- A more general issue for the use of probabilities in cosmology concerns the inadequacy of Bayesian and statistical model selection criteria in the absence of well-motivated measures for different cosmological models. The criteria for model selection commonly used tend to focus on optimizing the number of free parameters, but they can select physically implausible models. The fourth paper examines the possibility for Bayesian model selection to circumvent the lack of well-motivated priors. (shrink)