Vincenzo Fano

This paper examines the role of perspectivism in Relational Quantum Mechanics, situating it within the broader landscape of quantum interpretations and the scientific realism debate. We argue that, while interpretations such as QBism embrace strong forms of perspectivism, Relational Quantum Mechanics adopts a “soft” perspectivism, limiting the observer’s role to selecting experimental contexts without compromising its realist framework. We also explore the historical roots of Relational Quantum Mechanics, showing that relational ideas in the works of Bohr and other pioneers similarly avoided strong perspectivist commitments. By analyzing both contemporary and historical perspectives, we argue that Relational Quantum Mechanics offers a minimalist yet robust relational interpretation, distinct from more subjectivist approaches.

Since its inception in 1996, Rovelli’s Relational Quantum Mechanics (RQM) has left the status of non-interacting systems notably underexplored. When discussed at all, one prevailing view has maintained that attributing properties to isolated systems within RQM is simply meaningless. However, it has become increasingly evident that without a satisfying account of non-interacting systems, RQM risks sliding toward antirealist interpretations–at least insofar as such systems are concerned. In response to this crucial challenge, two main approaches have been advanced. One is a form of dispositionalism, which suggests that isolated physical systems possess only dispositional properties. The other appeals to a determinable-based account of metaphysical indeterminacy, suggesting that a non-interacting quantum system may bear a determinable property without possessing any unique determinate of that determinable at a given time. In this paper, we offer a new response to the question of what can be meaningfully said about quantum systems prior to measurement in the context of RQM. In particular, drawing on the formalism of Positive Operator-Valued Measures (POVMs), we emphasize that (1) preparation–like measurement–constitutes a physical interaction capable of assigning relational properties to a system, and that (2) POVMs are indispensable for the proper description of observables with continuous spectra. On this basis, we propose that RQM can accommodate an entity-realist interpretation of non-interacting systems by attributing to them what we term relational unsharp properties. As we will show, this theoretical move preserves the relational nucleus of RQM while enabling a physically and philosophically coherent account of non-interacting quantum systems.

The aim of this paper is to reconstruct the logical structure of Melissus philosophy, building on Laks Most’s translation and Barnes’ seminal work on the Samian. This will allow us to shed some light on the subtle argumentations of Melissus. On top of that, we frame Melissus’ metaphysics employing modern logical instruments. On one side, this reformulation makes clear a few assumptions hidden in the deductions made by the Samian; on the other side, our paper shows that contemporary analytic metaphysics has forerunners dating back 2500 years.

The arrow paradox is an argument purported to show that objects do not really move. The two main metaphysics of motion, the At–At theory of motion and velocity primitivism, solve the paradox differently. It is argued that neither solution is completely satisfactory. In particular it is contended that there are no decisive arguments in favor of the claim that velocity as it is constructed in the At–At theory is a truly instantaneous property, which is a crucial assumption to solve the paradox. If so the At–At theory faces the threat that most of our physical theories turn out to be non-Markovian. Finally it is considered whether all those threats and paradoxes are dispelled if only a new metaphysics of persistence is taken into account, namely four-dimensionalism.

Harrigan and Spekkens (Found Phys 40:125–157, 2010), introduced the influential notion of an ontological model of operational quantum theory. Ontological models can be either “epistemic” or “ontic.” According to the two scholars, Einstein would have been one of the first to propose an epistemic interpretation of quantum mechanics. Pusey et al. (Nat Phys 8:475–478, 2012) showed that an epistemic interpretation of quantum theory is impossible, so implying that Einstein had been refuted. We discuss in detail Einstein’s arguments against the standard interpretation of QM, proving that there is a misunderstanding in Harrigan and Spekkens’ attribution of an epistemic perspective to Einstein, whose point of view was actually statistical, but in a quasi-classical sense.

This collection focuses on the ontology of space and time. It is centred on the idea that the issues typically encountered in this area must be tackled from a multifarious perspective, paying attention to both a priori and a posteriori considerations. Several experts in this area contribute to this volume: G. Landini discusses how Russell’s conception of time features in his general philosophical perspective;D. Dieks proposes a middle course between substantivalist and relationist accounts of space-time;P. Graziani argues that it is necessary to provide an account of the “synthetic procedures” implicit in the recourse to diagrams in Euclid’s Elements, while E. Mares comes to the conclusion that in Euclid’s Elements we should treat the parallel postulate as empirical and the postulate that space is continuous as a priori. M. Arsenijevi?/M. Adži? present an important formal result concerning two theories of the infinite two-dimensional continua, which sheds new light on the current dispute between gunkologists and pointilists; F. Orilia discusses two problems for presentism, one regarding the duration of the present and the other related to Zeno’s paradoxes. A. Iacona delves deep into logical matters by focusing on the so-called T×W modal frames in order to deal with the deteterminism-indeterminism controversy. D. Mancuso outlines a non-standard temporal model compatible with time travel, andV. Fano/G. Macchia discuss time travels in the light of an important foundational principle of modern cosmology, Weyl’s Principle.

Reichenbach’s importance to the development of modern philosophy can hardly be overstated. However, many themes and arguments originally developed by Reichenbach are either overlooked or not properly credited to him. In this article, we discuss an important but often forgotten argument of Reichenbach against the Kantian notion of synthetic a priori. We first give a detailed historical reconstruction of the argument and discuss the mild conventionalism that Reichenbach developed following this argument. Then, we recast this argument in the modern language of General Relativity. We show that this argument is still relevant for a modern attempt at articulating the notion of synthetic a priori: Friedman’s relativised synthetic a priori.

This paper aims to construct an ontology grounded in the interpretation of Relational Quantum Mechanics, which serves as a robust framework for a realist interpretation of quantum mechanics without the need for additional theoretical constructs. Using the notion of relational properties, we formulate Relational Quantum Mechanics’s ontology. Our analysis highlights the ontological significance of Rovelli (Int. J. Theor. Phys., 35, 1637–1678, 1996)’spostulates. Moreover, we apply this ontological perspective to quantum mechanics paradoxes and show that it provides new insights into those paradoxes, underscoring Relational Quantum Mechanics explanatory power.

Great scholars in philosophy possess a keen analytical mind, excel in logical reasoning, and exhibit meticulous attention to detail. They rigorously define terms, avoiding ambiguities and errors. Originality and the willingness to challenge conventions are their hallmarks. They make significant contributions across various philosophical fields. They transparently address the exact aim of their research, and what it is not. Finally, they anticipate the impact of their theories on the current literature, and how such an impact should blossom across the future generations. In this respect, great philosophers address open problems and propose big questions for the foreseeable research efforts of those who will follow. Mario Alai embodies the qualities of a great scholar in philosophy, and the various essays in this volume are an evidence to that. It is challenging to condense a lifetime of research in one book. However, the Editors of the present volume’s aim was to face this challenge, to make a collection dedicated to Mario Alai’s work not only possible but, as metaphysicians would say, actual. The book attempts to bring together the reflections of three different generations of scholars - i.e., mentors, colleagues, and students - on Alai’s thought. Viewed from this perspective, the extensive and valuable contributions that follow, crafted in honor of Mario Alai and his scholarly endeavors, come as no surprise. All the chapters focus on a theme that was very dear to the philosophical curiosity of Mario Alai. Moreover, in engaging with these different topics, the plethora of contributions gives us a sense of the work by Alai. To make sense of the different contributions as a unified enterprise, this volume is organized into three sections, which seek to gather writings that revolve around Mario’s most substantial contributions, while elucidating their contemporary significance in the global discourse. Moreover, it endeavors to offer precious insights into the origins and development of these contributions, as observed through Mario’s writings and responses. This represents a sort of closure of the theoretical circle, clearly showing how the work by Mario Alai has been appreciated through different generations, originating from his relation to his mentors, on the one hand, while also shedding new light on his students’ research interests, on the other. Editing such a wealth of material was, again, no small feat. Still, the taxonomy we have chosen for this book will assist readers in navigating the profound depths of Alai’s philosophical research. Consequently, the book is structured into the following three parts: 1. Realism in History of Philosophy, History of Science, and Metaphysics. 2. Scientific Realism. 3. Realism in Philosophy of Language, Epistemology, and Experimental Philosophy. Each contribution actively participates in a substantial conversation with Alai’s body of work, as a deep theoretical dialogue between the author and Mario. Consequently, it appeared fitting to let Alai conclude this conversation, with direct responses to these philosophy-provoking pieces in his honor. We shall refrain from further commentary on the works within this book and allow them to express their significance independently to appreciate the river of ideas flowing through Mario’s work1. Beyond their philosophical substance, they are a vivid testament to Alai’s enduring dedication and ongoing contributions, in different moments of his research life.

The aim of this paper is to address the question: when does a physical system realize (implement) a certain computation? The most developed account that answers this question is Piccinini’s mechanistic account. Our strategy is to start from Piccinini’s reflections, emphasizing different aspects of the problem of realization and thus proposing a novel account. Our idea is to propose a new definition of realization that makes the original question more tractable and easier to scrutinize. We show that our definition has some advantages when dealing with classical objections to accounts of computation in physical systems.The paper is structured in four parts: after the introduction, the first part will introduce mapping accounts of implementation discussing some of their problematic aspects; the second part will present and clarify some prerequisite notions for a definition of realization; the third part will introduce our definition – it will turn out that our definition will identify a specific kind of strategy that Piccinini (2015a, b) calls nomological mapping account; the fourth and final part will be dedicated to analysing the advantages of our definition. Concluding remarks follow.

In this paper we will address the question whether a space interval is a set of infinite points. It is a very old problem, but despite its age it is still a live issue, and one we have to confront. We will analyze some topics regarding this question using the most influential objections against it, i.e. The Large and the Small paradox (in particular its Small Horn). We will consider classical contemporary reformulations of the argument (Grünbaum in Philosophy of Science 19:280–306, 1952; Grünbaum in Modern science and Zeno’s paradoxes. Allen and Unwin, London, 1968) and the possible ‘solutions’ to it. Finally, we will propose a new formulation of the paradox and analyze its consequences. In particular, we will bring further arguments supporting the standard thesis that it is possible that a segment of space is composed of a non-denumerable set of indivisible 0-length points.

Hermeneutical scholars doubt whether many past authors really existed. They are only a sort of construction built with the passing of time. Indeed, Zeno of Elea, for instance, was real, and historians attempted to establish what he wrote and intended to say. Our most important source for Zeno is Aristotle. Zeno’s paradoxes deeply influenced the latter’s Physics. Is Aristotle’s physics relevant to us? Yes, because philosophical problems are too complex not to be considered in their historical development as well. In reading Zeno and Aristotle, we can see physical problems from a completely different perspective and learn a lot. In other terms, the historical Zeno is disorienting for us. On the other hand, Zeno’s historical legacy is extremely interesting for us. Indeed, we will see how Zeno’s and Aristotle’s reflections on continuum, extension, and movement could contribute to a better understanding of these notions in the contemporary debate.

This paper conducts a Bayesian analysis of the Hubble tension, which addresses the discrepancy between local measurements of the Hubble Constant $$H_0$$ and the value predicted by the $$\Lambda $$ CDM model based on Cosmic Microwave Background data. By incorporating new, independent data from the James Webb Space Telescope released in August 2024, the analysis shows that, unlike before, there is no longer strong evidence to suggest that the $$\Lambda $$ CDM model is incorrect. As a result, the Hubble tension appears to ease somewhat, indicating that the previously perceived crisis in cosmology may have been overstated, and the standard model remains robust.

The scientific literature on Wigner’s Friend extended paradox rapidly grew in the last years. A sign that Frauchiger and Renner (2018)’s argument caught an important point. Indeed, they conclude that either we must abandon the universal validity of quantum mechanics, or a certain kind of traditional objective knowledge is impossible. We investigate this contradiction through a logico-epistemic toolbox. We show that abandoning the transmissibility of knowledge, as proposed by many kinds of relational approaches to quantum mechanics, is a heavy epistemological renouncement. Perhaps, it is better to bite the bullet and accept Frauchiger and Renner’s contradiction, until a new revolutionary solution will appear.

The paper addresses the main meta-metaphysical question, i.e., whether it is possible to do metaphysics and, in the case of an affirmative answer, how should we do it? With such an aim in mind, we sketch the broad context in which these meta-metaphysical questions arose in the philosophical literature (§ 1); then, we present what we take to be the three most widespread conceptions of metaphysics that are available in the analytic tradition: the neo-Quinean (§ 2), metaphysics as the science of possibilities (§ 3) and metaphysics as the study of the fundamental structures of reality (§ 4). We criticise these positions throughout these paragraphs before cashing out our proposal (§ 5). Our interpretation aligns with the recently proposed approach known as ‘naturalised metaphysics’ but with crucial differences. In our view, metaphysics is not only constrained by physics; rather, it grows out from all empirical sciences. More precisely, it can be achieved using formal language and the analysis of the results of scientific theories.

SARS-CoV-2 vaccines are indispensable allies in the fight against COVID-19. Behavioral and cognitive scientists have argued for taking advantage of insights from their fields of investigations in shaping anti-COVID policies. B&C scientists extensively discussed the methodological and practical issues that arise in translating B&C research results into policy interventions aimed to boost vaccination, Nevertheless, the same cannot be said for the ethical aspects. In the present work, we discuss the ethics of nudging vaccination in light of the “alien control” objection, a kind of control whereby an agent has the power to influence the choice of another agent, and the latter cannot control such power. We proceed as follows. We begin by presenting several cases of mandatory policies avaiable to policymakers to boost the vaccine rate. Next, we point out that insights from B&C sciences can inform mandatory policies and open up ways to enhance them. In section 3, we focus on untraditional policy tools, viz. nudges. In the second part of the article, we introduce the debate on the ethics of nudges, focusing on the “alien control” objection and its relevance for the citizens’ freedom and autonomy. We therefore discuss the original point of the paper. We argue that, referring to nudging vaccination, a somehow neglected ethical issue posed by nudges emerges. Our point is that nudges do not exert exclusively an influence over a targeted behavior. Indeed, nudges impose as well a political influence by which citizens are treated as means to succeed in achieving a peculiar, and potentially controversial, political aim. We argue that, due to what we propose to call the “political multi-justifiability" of nudges, their political influence cannot be detected by citizens. This leads to the threat of alien control. In the last section, we draw some tentative conclusions, suggest a possible solution and its practical advantages.

_Abstract_: Nudges have proven to be effective tools for steering citizens toward desirable behaviors and make valuable additions to any policy-maker’s toolbox. Disappointingly, however, there are no mechanistic explanations for how nudges work, leaving policy-makers unable to explain what happens when they are implemented. This paper identifies some neglected ethical implications of the resulting citizens lack of awareness of such mechanisms. We first examine mechanistic explanations in relation to citizens’ understanding on how they work. Then, we look at mechanistic explanations in light of the suggestion advanced by some ethicists that nudges be considered ethically acceptable in modern liberal democracies provided the explicit transparency of the nudges employed. _Keywords_: Nudge; Ethics of Nudging; Mechanistic Evidence; In-principle Transparency; Explicit Transparency _Spiegazioni meccanicistiche e l’etica dei _nudges _Riassunto_: I _nudge_ si sono rivelati strumenti di _policy_ efficaci nello "spingere gentilmente" i cittadini verso comportamenti considerati desiderabili. Per questa ragione i nudge sono considerati validi strumenti della cassetta degli attrezzi di un _policymaker_. Tuttavia, è in qualche modo deludente la mancanza di spiegazioni meccanicistiche dei nudge, dalla quale risulta l'incapacità dei _policymaker_ di spiegare quello che succede quando i nudge vengono effettivamente implementati. Questo articolo identifica alcune implicazioni etiche finora trascurate connesse alla inconsapevolezza da parte dei cittadini circa i meccanismi che governano i _nudge_. Da una parte, le nostre considerazioni metteranno in relazione le spiegazioni meccanicistiche con la comprensione dei _nudge_ da parte dei cittadini. Dall'altra parte, metteremo in relazione le spiegazioni meccanicistiche con il concetto di trasparenza esplicita, ossia la richiesta avanzata da alcuni eticisti al fine di considerare i _nudge_ eticamente accettabili nelle moderne democrazie liberali. _Parole chiave_: Nudge; Etica dei nudge; Spiegazioni meccanicistiche; Trasparenza implicita; Trasparenza esplicita.

In the logical context, ignorance is traditionally defined recurring to epistemic logic. In particular, ignorance is essentially interpreted as “lack of knowledge”. This received view has - as we point out - some problems, in particular we will highlight how it does not allow to express a type of content-theoretic ignorance, i.e. an ignorance of φ that stems from an unfamiliarity with its meaning. Contrarily to this trend, in this paper, we introduce and investigate a modal logic having a primitive epistemic operator I, modeling ignorance. Our modal logic is essentially constructed on the modal logics based on weak Kleene three-valued logic introduced by Segerberg (Theoria, 33(1):53–71, 1997). Such non-classical propositional basis allows to define a Kripke-style semantics with the following, very intuitive, interpretation: a formula φ is ignored by an agent if φ is neither true nor false in every world accessible to the agent. As a consequence of this choice, we obtain a type of content-theoretic notion of ignorance, which is essentially different from the traditional approach. We dub it severe ignorance. We axiomatize, prove completeness and decidability for the logic of reflexive (three-valued) Kripke frames, which we find the most suitable candidate for our novel proposal and, finally, compare our approach with the most traditional one.

Les modèles mathématiques peuvent être utilisés avec profit pour établir si notre perception du monde extérieur est précis. Donald Hoffman et ses collaborateurs ont développé un cadre mathématique prometteur dans lequel cette question peut être abordée, et qui repose sur une taxonomie exhaustive des différentes relations possibles qui peuvent tenir entre les représentations perceptuelles et le monde extérieur. Après avoir reformulé leur cadre au moyen d’un système formel amélioré, nous discutons de leur application de la théorie des jeux évolutifs, qui semble montrer qu’une stratégie perceptuelle essentiellement anti-réaliste à long terme surpasserait biologiquement ses rivaux. Nous soutenons que leur modèle ne prend pas dûment en considération la signification biologique cruciale des changements environnementaux et proposons des modèles alternatifs qui le font. Nous concluons que, dans nos modèles, une représentation partiellement réaliste serait privilégiée.

In this paper, we argue that Williamson’s arguments against luminosity and the KK principle do not work, at least in a scientific context. Both of these arguments are based on the presence of a so-called “buffer zone” between situations in which one is in a position to know p and situations in which one is in a position to know ¬p. In those positions belonging to the buffer zone ¬p holds, but one is not in a position to know ¬p. The presence of this buffer zone triggers two types of sorites arguments. We show that this kind of argument does not hold in a scientific context, where the buffer zone is controlled by a quantitative measurement of the experimental error.

The aim of this paper is to reconstruct the logical structure of Melissus philosophy, building on Laks Most’s translation and Barnes’ seminal work on the Samian. This will allow us to shed some light on the subtle argumentations of Melissus. On top of that, we frame Melissus’ metaphysics employing modern logical instruments. On one side, this reformulation makes clear a few assumptions hidden in the deductions made by the Samian; on the other side, our paper shows that contemporary analytic metaphysics has forerunners dating back 2500 years.

The Dunning–Kruger effect focuses our attention on the notion of invisibility of ignorance, i.e., the ignorance of ignorance. Such a phenomenon is not only important for everyday life, but also, above all, for some philosophical disciplines, such as epistemology of sciences. When someone tries to understand formally the phenomenon of ignorance of ignorance, they usually end up with a nested epistemic operator highly resistant to proper regimentation. In this paper, we argue that to understand adequately the ignorance of ignorance phenomenon we have to understand satisfactorily the concept of disbelief and, as we call it, the concept of “radical ignorance”. We propose also prerequisites that a notion of radical ignorance useful for the philosophy of science ought to fulfill, and we sketch a possible formalization of this notion. Finally, we propose some comments on the problem of propagation of ignorance proposed by Fine.