Constitutivism argues that the source of the categorical force of the norms of rationality and morality lies in the constitutive features of agency. A systematic failure to be guided by these norms would amount to a loss or lack of agency. Since we cannot but be agents, we cannot but be unconditionally guided by these norms. The constitutivist strategy has been challenged by David Enoch. He argues that our participation in agency is optional and thus cannot be a source of (...) categorical demands. In this paper, I defend the viability of constitutivism by showing that agency is indeed a special ‘inescapable’ enterprise. Agency has the largest jurisdiction, and it is closed under rational assessment. This inescapability does not exempt constitutivism from raising the question whether agents have reason to be agents, but this question has to be taken up within agency. If this question is answered affirmatively, then—I argue—the criteria of practical correctness are self-ratifying in a non-circular way. This is sufficient to show the viability of the constitutivist strategy. Whether agents have conclusive reasons to be agents, however, is a matter to be addressed in the terms of particular versions of constitutivism. (shrink)

It is often argued that future-directed decisions are effective at shaping our future conduct because they give rise, at the time of action, to a decisive reason to act as originally decided. In this paper, I argue that standard accounts of decision-based reasons are unsatisfactory. For they focus either on tie-breaking scenarios or cases of self-directed distal manipulation. I argue that future-directed decisions are better understood as tools for the non-manipulative, intrapersonal division of deliberative labor over time. A future-directed decision (...) to ϕ gives rise to a defeasible exclusionary reason to ϕ. This reason is grounded on the default authority that is normally granted to one’s prior self as an “expert” deliberator. I argue that this kind of exclusionary reason is the only one that can account for the effectiveness of future-directed decisions at shaping our diachronic agency without violating our autonomy over time. (shrink)

We present epistemic multilateral logic, a general logical framework for reasoning involving epistemic modality. Standard bilateral systems use propositional formulae marked with signs for assertion and rejection. Epistemic multilateral logic extends standard bilateral systems with a sign for the speech act of weak assertion (Incurvati and Schlöder 2019) and an operator for epistemic modality. We prove that epistemic multilateral logic is sound and complete with respect to the modal logic S5 modulo an appropriate translation. The logical framework developed provides the (...) basis for a novel, proof-theoretic approach to the study of epistemic modality. To demonstrate the fruitfulness of the approach, we show how the framework allows us to reconcile classical logic with the contradictoriness of so-called Yalcin sentences and to distinguish between various inference patterns on the basis of the epistemic properties they preserve. (shrink)

In this paper, I will discuss the various ways in which intentions can be said to be conditional, with particular attention to the internal conditions on the intentions’ content. I will first consider what it takes to carry out a conditional intention. I will then discuss how the distinctive norms of intention apply to conditional intentions and whether conditional intentions are a weaker sort of commitments than the unconditional ones. This discussion will lead to the idea of what I call (...) the ‘deep structure’ of intentions. Roughly, this is the idea that the conditional nature of our intentions is only partially made explicit in the expressions we use to communicate our intentions and in the explicit form of our thinking about and reasoning with them. Most conditions that qualify our intentions are part of a deep functional structure that can be evinced by observing the actual psychological functioning of intentions and by considering the rational requirements that they engage. I will argue that the deep structure of intentions is characteristically conditional. Genuinely unconditional intentions are only limiting instances of conditional intentions and their contribution to agency can only be understood in light of this fact. I will conclude by showing that the characteristic conditional structure of intentions is intimately related to distinctive features of human agency, especially to its unity over time. (shrink)

ABSTRACTLinguistic evidence supports the claim that certain, weak rejections are less specific than assertions. On the basis of this evidence, it has been argued that rejected sentences cannot be premisses and conclusions in inferences. We give examples of inferences with weakly rejected sentences as premisses and conclusions. We then propose a logic of weak rejection which accounts for the relevant phenomena and is motivated by principles of coherence in dialogue. We give a semantics for which this logic is sound and (...) complete, show that it axiomatizes the modal logic KD45 and prove that it still derives classical logic on its asserted fragment. Finally, we defend previous logics of strong rejection as being about the linguistically preferred interpretations of weak rejections. (shrink)

This contribution deals with the ethical challenges arising from the IoT landscape with reference to a specific context, i.e. the realm of agri-food. In this sector, innumerable web-connected tools, platforms and sensors are constantly interacting with consumers/users/citizens, by reshaping and redefining the core elements and functions of machine–human being relationships. By sketching out the main pillars which ethics of the Internet of Food is founded on, my argument posits that the civic hybridization of knowledge production mediated by IoT technologies may (...) create breeding ground for the move towards an ‘ethical in-design’ approach to the IoF-driven smart systems. (shrink)

In this paper we focus on transmission and failure of transmission of warrant. We identify three individually necessary and jointly sufficient conditions for transmission of warrant, and we show that their satisfaction grounds a number of interesting epistemic phenomena that have not been sufficiently appreciated in the literature. We then scrutinise Wright’s analysis of transmission failure and improve on extant readings of it. Nonetheless, we present a Bayesian counterexample that shows that Wright’s analysis is partially incoherent with our analysis of (...) warrant transmission and prima facie defective. We conclude exploring three alternative lines of reply: developing a more satisfactory account of transmission failure, which we outline; dismissing the Bayesian counterexample by rejecting some of its assumptions; reinterpreting Wright’s analysis to make it immune to the counterexample. (shrink)

The subject of Labelled Non-Classical Logics is the development and investigation of a framework for the modular and uniform presentation and implementation of non-classical logics, in particular modal and relevance logics. Logics are presented as labelled deduction systems, which are proved to be sound and complete with respect to the corresponding Kripke-style semantics. We investigate the proof theory of our systems, and show them to possess structural properties such as normalization and the subformula property, which we exploit not only to (...) establish advantages and limitations of our approach with respect to related ones, but also to give, by means of a substructural analysis, a new proof-theoretic method for investigating decidability and complexity of (some of) the logics we consider. All of our deduction systems have been implemented in the generic theorem prover Isabelle, thus providing a simple and natural environment for interactive proof development. Labelled Non-Classical Logics is essential reading for researchers and practitioners interested in the theory and applications of non-classical logics. (shrink)

We present an inferentialist account of the epistemic modal operator might. Our starting point is the bilateralist programme. A bilateralist explains the operator not in terms of the speech act of rejection ; we explain the operator might in terms of weak assertion, a speech act whose existence we argue for on the basis of linguistic evidence. We show that our account of might provides a solution to certain well-known puzzles about the semantics of modal vocabulary whilst retaining classical logic. (...) This demonstrates that an inferentialist approach to meaning can be successfully extended beyond the core logical constants. (shrink)

Crispin Wright has given an explanation of how a first time warrant can fall short of transmitting across a known entailment. Formal epistemologists have struggled to turn Wright’s informal explanation into cogent Bayesian reasoning. In this paper, I analyse two Bayesian models of Wright’s account respectively proposed by Samir Okasha and Jake Chandler. I argue that both formalizations are unsatisfactory for different reasons, and I lay down a third Bayesian model that appears to me to capture the valid kernel of (...) Wright’s explanation. After this, I consider a recent development in Wright’s account of transmission failure. Wright suggests that his condition sufficient for transmission failure of first time warrant also suffices for transmission failure of supplementary warrant. I propose an interpretation of Wright’s suggestion that shield it from objections. I then lay down a fourth Bayesian framework that provides a simplified model of the unified explanation of transmission failure envisaged by Wright. (shrink)

According to the iterative conception of set, sets can be arranged in a cumulative hierarchy divided into levels. But why should we think this to be the case? The standard answer in the philosophical literature is that sets are somehow constituted by their members. In the first part of the paper, I present a number of problems for this answer, paying special attention to the view that sets are metaphysically dependent upon their members. In the second part of the paper, (...) I outline a different approach, which circumvents these problems by dispensing with the priority or dependence relation altogether. Along the way, I show how this approach enables the mathematical structuralist to defuse an objection recently raised against her view. (shrink)

Timothy Smiley’s wonderful paper ‘Rejection’ (1996) is still perhaps not as well known or well understood as it should be. This note first gives a quick presentation of themes from that paper, though done in our own way, and then considers a putative line of objection – recently advanced by Julien Murzi and Ole Hjortland (2009) – to one of Smiley’s key claims. Along the way, we consider the prospects for an intuitionistic approach to some of the issues discussed in (...) Smiley’s paper. (shrink)

We discuss a well-known puzzle about the lexicalization of logical operators in natural language, in particular connectives and quantifiers. Of the many logically possible operators, only few appear in the lexicon of natural languages: the connectives in English, for example, are conjunction _and_, disjunction _or_, and negated disjunction _nor_; the lexical quantifiers are _all, some_ and _no_. The logically possible nand (negated conjunction) and Nall (negated universal) are not expressed by lexical entries in English, nor in any natural language. Moreover, (...) the lexicalized operators are all upward or downward monotone, an observation known as the Monotonicity Universal. We propose a logical explanation of lexical gaps and of the Monotonicity Universal, based on the dynamic behaviour of connectives and quantifiers. We define update potentials for logical operators as procedures to modify the context, under the assumption that an update by $\phi$ depends on the logical form of $\phi$ and on the speech act performed: assertion or rejection. We conjecture that the adequacy of update potentials determines the limits of lexicalizability for logical operators in natural language. Finally, we show that on this framework the Monotonicity Universal follows from the logical properties of the updates that correspond to each operator. (shrink)

Coherentism in epistemology has long suffered from lack of formal and quantitative explication of the notion of coherence. One might hope that probabilistic accounts of coherence such as those proposed by Lewis, Shogenji, Olsson, Fitelson, and Bovens and Hartmann will finally help solve this problem. This paper shows, however, that those accounts have a serious common problem: the problem of belief individuation. The coherence degree that each of the accounts assigns to an information set (or the verdict it gives as (...) to whether the set is coherent tout court) depends on how beliefs (or propositions) that represent the set are individuated. Indeed, logically equivalent belief sets that represent the same information set can be given drastically different degrees of coherence. This feature clashes with our natural and reasonable expectation that the coherence degree of a belief set does not change unless the believer adds essentially new information to the set or drops old information from it; or, to put it simply, that the believer cannot raise or lower the degree of coherence by purely logical reasoning. None of the accounts in question can adequately deal with coherence once logical inferences get into the picture. Toward the end of the paper, another notion of coherence that takes into account not only the contents but also the origins (or sources) of the relevant beliefs is considered. It is argued that this notion of coherence is of dubious significance, and that it does not help solve the problem of belief individuation. (shrink)

We develop a novel solution to the negation version of the Frege-Geach problem by taking up recent insights from the bilateral programme in logic. Bilateralists derive the meaning of negation from a primitive *B-type* inconsistency involving the attitudes of assent and dissent. Some may demand an explanation of this inconsistency in simpler terms, but we argue that bilateralism’s assumptions are no less explanatory than those of *A-type* semantics that only require a single primitive attitude, but must stipulate inconsistency elsewhere. Based (...) on these insights, we develop a version of B-type expressivism called *inferential expressivism*. This is a novel semantic framework that characterises meanings by inferential roles that define which *attitudes* one can *infer* from the use of terms. We apply this framework to normative vocabulary, thereby solving the Frege-Geach problem generally and comprehensively. Our account moreover includes a semantics for epistemic modals, thereby also explaining normative terms under epistemic modals. (shrink)

A citizen of Early Renaissance Florence that stepped out into the streets and entered the spaces of his civic world joined a concert of creative formal behaviors in which he was at once an actor and a spectator. His problem here was to interpret the complex web of overlapping, conflicting and simultaneous meanings he would have read in the actions and images by which the community directed him and represented itself, and find his own place and set his standing. On (...) most occasions he would probably have elected for a state of suspension, a floating of multiple possibilities he was loath to precipitate in too stable a form: in ambiguity the citizen of Florence developed a richness of signification, and found a refuge. (shrink)

Cet ouvrage est issu du colloque Beyond East and West. Hellenistic Commagene in its Local and Global Eurasian Contest, organisé en 2018 à l’Université de Münster. Prenant place dans le cadre d’une collaboration entre le Forschungsstelle Asia Minor et le cluster of excellence « Religion and Politics », ce rassemblement a vu la constitution d’un panel impressionnant de chercheurs issus de différentes disciplines. Le livre qui en résulte se présente sous la forme de 19 contributions réparties en...

In Aristophanes' Male and Female Revolutions author Kenneth M. De Luca offers a detailed study of two of Aristophanes' plays and reveals how each illuminates the other and the question of the rule of law through the lens of democracy. De Luca uses classical thought to clarify contemporary and foundational issues in political theory.

This desk-based-study explores, on the basis of a Critical Realist perspective, the possibility to integrate the concept of Learning Cultures within the scope of Critical Discourse Analysis. It proposes a theoretical framework to support and guide the use of textual analysis in the study of Learning Cultures and highlights new opportunities to study technology enhanced learning communities and communities of practice, leveraging on Corpora Analysis and Metaphor Individuation Procedures.

Recent works in epistemology show that the claim that coherence is truth conducive – in the sense that, given suitable ceteris paribus conditions, more coherent sets of statements are always more probable – is dubious and possibly false. From this, it does not follows that coherence is a useless notion in epistemology and philosophy of science. Dietrich and Moretti (Philosophy of science 72(3): 403–424, 2005) have proposed a formal of account of how coherence is confirmation conducive—that is, of how the (...) coherence of a set of statements facilitates the confirmation of such statements. This account is grounded in two confirmation transmission properties that are satisfied by some of the measures of coherence recently proposed in the literature. These properties explicate everyday and scientific uses of coherence. In his paper, I review the main findings of Dietrich and Moretti (2005) and define two evidence-gathering properties that are satisfied by the same measures of coherence and constitute further ways in which coherence is confirmation conducive. At least one of these properties vindicates important applications of the notion of coherence in everyday life and in science. (shrink)

In this paper, I argue against the popular philosophical thesis---aka the ‘own action condition’---that an agent can only intend one’s own actions. I argue that the own action condition does not hold for any executive attitude, intentions included. The proper object of intentions is propositional rather than agential (‘I intend that so-and-so be the case’ rather than ‘I intend to do such-and-such’). I show that, although there are some essential de se components in intending, they do not restrict the content (...) of intentions to one’s own actions. I then discuss the special way in which one’s own actions can figure in the content of one’s intentions, which shows that the distinction between intending and acting is less stark than it appears at first. This is a conclusion that many defenders of the own action condition might find appealing but which, I argue, is better supported by rejecting the own action condition. (shrink)

A 'self-refutation argument' is any argument which aims at showing that a certain thesis is self-refuting. This study was the first book-length treatment of ancient self-refutation and provides a unified account of what is distinctive in the ancient approach to the self-refutation argument, on the basis of close philological, logical and historical analysis of a variety of sources. It examines the logic, force and prospects of this original style of argumentation within the context of ancient philosophical debates, dispelling various misconceptions (...) concerning its nature and purpose and elucidating some important differences which exist both within the ancient approach to self-refutation and between that approach, as a whole, and some modern counterparts of it. In providing a comprehensive account of ancient self-refutation, the book advances our understanding of influential and debated texts and arguments from philosophers like Democritus, Plato, Aristotle, Epicurus, the Stoics, the Academic sceptics, the Pyrrhonists and Augustine. (shrink)

Many classically valid meta-inferences fail in a standard supervaluationist framework. This allegedly prevents supervaluationism from offering an account of good deductive reasoning. We provide a proof system for supervaluationist logic which includes supervaluationistically acceptable versions of the classical meta-inferences. The proof system emerges naturally by thinking of truth as licensing assertion, falsity as licensing negative assertion and lack of truth-value as licensing rejection and weak assertion. Moreover, the proof system respects well-known criteria for the admissibility of inference rules. Thus, supervaluationists (...) can provide an account of good deductive reasoning. Our proof system moreover brings to light how one can revise the standard supervaluationist framework to make room for higher-order vagueness. We prove that the resulting logic is sound and complete with respect to the consequence relation that preserves truth in a model of the non-normal modal logic _NT_. Finally, we extend our approach to a first-order setting and show that supervaluationism can treat vagueness in the same way at every order. The failure of conditional proof and other meta-inferences is a crucial ingredient in this treatment and hence should be embraced, not lamented. (shrink)

The paper introduces what is deemed as the general epistemological problem of measurement: what characterizes measurement with respect to generic evaluation? It also analyzes the fundamental positions that have been maintained about this issue, thus presenting some sketches for a conceptual history of measurement. This characterization, in which three distinct standpoints are recognized, corresponding to a metaphysical, an anti-metaphysical, and relativistic period, allows us to introduce and briefly discuss some general issues on the current epistemological status of measurement science.

There are two standard conceptions of the functioning of and rationale for the diachronic will, i.e., for an agent's capacity to settle on her future conduct in advance. According to the pragmatic-instrumentalist view, the diachronic will benefits us by increasing the long-term satisfaction of our rational preferences. According to the cognitive view, it benefits us by satisfying our standing desire for self-knowledge and self-understanding. Contrary to these views, I argue for a constitutive view of the diachronic will: the rationale for (...) it is that it makes possible to engage in activities with a radically novel temporal structure, activities that are not merely continuous over time, but temporally integrated and unified. These activities are essential to our form of life and to our existence as temporally unified agents. The instrumental and cognitive benefits, if any, are merely secondary to the ontological ones. (shrink)

The Schön misconduct case has been widely publicized in the media and has sparked intense discussions within and outside the scientific community about general issues of science ethics. This paper analyses the Report of the official Committee charged with the investigation in order to show that what at first seems to be a quite uncontroversial case, turns out to be an accumulation of many interesting and non-trivial questions (of both ethical and philosophical interest). In particular, the paper intends to show (...) that daily scientific practices are structurally permeated by chronic problems; this has serious consequences for how practicing scientists assess their work in general, and scientific misconduct in particular. A philosophical approach is proposed that sees scientific method and scientific ethics as inextricably interwoven. Furthermore, the paper intends to show that the definition of co-authorship that the members of the Committee use, although perhaps clear in theory, proves highly problematic in practice and raises more questions that it answers. A final plea is made for a more self-reflecting attitude of scientists as far as the moral and methodological profile of science is concerned as a key element for improving not only their scientific achievements, but also their assessment of problematic cases. (shrink)

According to constitutivism, the objective authority of practical reason is to be grounded in the constitutive features of agency. In this paper, I offer a brief survey of the basic structure of constitutive argument about objectivity and consider how constitutivism might dispel the worry that it can only ground a conditional kind of authority. I then consider David Enoch’s original shmagency challenge and the response in terms of the inescapability of agency. In particular, I revisit the appeal to inescapability in (...) light of Enoch’s restatement of the challenge in 'Shmagency Revisited'. I argue that the revised challenge still fails but that it helps clarify: first, the distinction between external and internal challenges to constitutivism, and, second, the existence of at least different kinds of inescapability of agency (metaphysical, psychological, and dialectical). I argue that only dialectical inescapability is helpful to show that constitutivism is a viable metanormative theory. I conclude by claiming that an internal challenge to constitutivism is still possible in principle but that the burden of proof has shifted once again to the critics of constitutivism. (shrink)

In this paper, three theories of progress and the aim of science are discussed: the theory of progress as increasing explanatory power, advocated by Popper in The logic of scientific discovery ; the theory of progress as approximation to the truth, introduced by Popper in Conjectures and refutations ; the theory of progress as a steady increase of competing alternatives, which Feyerabend put forward in the essay “Reply to criticism. Comments on Smart, Sellars and Putnam” and defended as late as (...) the last edition of Against method. It is argued that, contrary to what Feyerabend scholars have predominantly assumed, Feyerabend's changing attitude towards falsificationism—which he often advocated at the beginning of his career, and vociferously attacked in the 1970s and 1980s—must be explained by taking into account not only Feyerabend's very peculiar view of the aim of science, but also Popper's changing account of progress. (shrink)

O problema deste paper constitui-se a partir da seguinte pergunta: seria Platão um plagiador dos pitagóricos? A suspeita nasce de uma tradição já antiga pela qual Platão é acusado de ter plagiado uma suposta obra atualmente perdida de Filolau de Crotona. Tomou-se, então, como objeto de análise, a obra Timeu, a fim de verificar a existência de trechos que poderiam sugerir um plágio por parte de Platão. Para tanto, realizou-se um levantamento das principais teorias “pitagóricas” identificáveis no Timeu, a partir (...) de uma revisão da história da crítica. Concluiu-se que, inegavelmente, há referência implícita ao pitagorismo na obra, a qual, entretanto, não configura propriamente um plágio, mas, sim, pode ser melhor considerada como uma influência pitagórica. Efetivamente, Platão acaba por transpor diversas teorias “pitagóricas” – bem como de outros filósofos pré-socráticos – para seus próprios interesses filosóficos. (shrink)

Deflationists about truth hold that the function of the truth predicate is to enable us to make certain assertions we could not otherwise make. Pragmatists claim that the utility of negation lies in its role in registering incompatibility. The pragmatist insight about negation has been successfully incorporated into bilateral theories of content, which take the meaning of negation to be inferentially explained in terms of the speech act of rejection. We implement the deflationist insight in a bilateral theory by taking (...) the meaning of the truth predicate to be explained by its inferential relation to assertion. We combine this account of the meaning of the truth predicate with a new diagnosis of the Liar Paradox: its derivation requires the truth rules to preserve evidence, but these rules only preserve commitment. The result is a novel inferential deflationist theory of truth, which solves the Liar Paradox in a principled manner. We end by showing that our theory and simple extensions thereof have the resources to axiomatize the internal logic of several supervaluational hierarchies, including Cantini’s. This solves open problems of Halbach (2011) and Horsten (2011). (shrink)

We show that if Ƒ is any "well-behaved" subset of the Borei functions and we assume the Axiom of Determinacy then the hierarchy of degrees on $P(^\omega \omega )$ induced by Ƒ turns out to look like the Wadge hierarchy (which is the special case where Ƒ is the set of continuous functions).

Crispin Wright’s entitlement theory holds that we have non-evidential justification for accepting propositions of a general type––which Wright calls “cornerstones”––that enables us to acquire justification for believing other propositions––those that we take to be true on the grounds of ordinary evidence. Entitlement theory is meant by Wright to deliver a forceful response to the sceptic who argues that we cannot justify ordinary beliefs. I initially focus on strategic entitlement, which is one of the types of entitlement that Wright has described (...) in more detail. I suggest that it is dubious that we are strategically entitled to accept cornerstones. After this, I focus on entitlement in general. I contend that, in important cases, non-evidential justification for accepting cornerstones cannot secure evidential justification for believing ordinary propositions. My argument rests on a probabilistic regimentation of the so-called “leaching problem”. (shrink)

In set theory, a maximality principle is a principle that asserts some maximality property of the universe of sets or some part thereof. Set theorists have formulated a variety of maximality principles in order to settle statements left undecided by current standard set theory. In addition, philosophers of mathematics have explored maximality principles whilst attempting to prove categoricity theorems for set theory or providing criteria for selecting foundational theories. This article reviews recent work concerned with the formulation, investigation and justification (...) of maximality principles. (shrink)

This paper criticizes phenomenal conservatism––the influential view according to which a subject S’s seeming that P provides S with defeasible justification for believing P. I argue that phenomenal conservatism, if true at all, has a significant limitation: seeming-based justification is elusive because S can easily lose it by just reflecting on her seemings and speculating about their causes––I call this the problem of reflective awareness. Because of this limitation, phenomenal conservatism doesn’t have all the epistemic merits attributed to it by (...) its advocates. If true, phenomenal conservatism would constitute a unified theory of epistemic justification capable of giving everyday epistemic practices a rationale, but it wouldn’t afford us the means of an effective response to the sceptic. Furthermore, phenomenal conservatism couldn’t form the general basis for foundationalism. (shrink)

The analytical notion of ‘scientific style of reasoning’, introduced by Ian Hacking in the middle of the 1980s, has become widespread in the literature of the history and philosophy of science. However, scholars have rarely made explicit the philosophical assumptions and the research objectives underlying the notion of style: what are its philosophical roots? How does the notion of style fit into the area of research of historical epistemology? What does a comparison between Hacking’s project on styles of thinking and (...) other similar projects suggest? My aim in this paper is to answer these questions. Hacking has denied that his project of styles of thinking falls into the field of historical epistemology. I shall challenge his remark by tracing out the connections of the notion of style with historical epistemology and, more in general, with a tradition of thought born in France in the beginning of twentieth-century. (shrink)

The paper introduces and formally defines a functional concept of a measuring system, on this basis characterizing the measurement as an evaluation performed by means of a calibrated measuring system. The distinction between exact and uncertain measurement is formalized in terms of the properties of the traceability chain joining the measuring system to the primary standard. The consequence is drawn that uncertain measurements lose the property of relation-preservation, on which the very concept of measurement is founded according to the representational (...) viewpoint. Finally, from the analysis of the inter-relations between calibration and measurement the fundamental reasons of the claimed objectivity and intersubjectivity of measurement are highlighted, a valuable epistemological result to characterize measurement as a particular kind of evaluation. (shrink)

We investigate the complexity of embeddings between bi-embeddable structures. In analogy with categoricity spectra, we define the bi-embeddable categoricity spectrum of a structure A as the family of Turing degrees that compute embeddings between any computable bi-embeddable copies of A; the degree of bi-embeddable categoricity of A is the least degree in this spectrum (if it exists). We extend many known results about categoricity spectra to the case of bi-embeddability. In particular, we exhibit structures without degree of bi-embeddable categoricity, and (...) we show that every degree d.c.e above 0(α) for α a computable successor ordinal and 0(λ) for λ a computable limit ordinal is a degree of bi-embeddable categoricity. We also give examples of families of degrees that are not bi-embeddable categoricity spectra. (shrink)