This paper discusses the Uniqueness Thesis, a core thesis in the epistemology of disagreement. After presenting uniqueness and clarifying relevant terms, a novel counterexample to the thesis will be introduced. This counterexample involves logical disagreement. Several objections to the counterexample are then considered, and it is argued that the best responses to the counterexample all undermine the initial motivation for uniqueness.

The Uniqueness Thesis holds, roughly speaking, that there is a unique rational response to any particular body of evidence. We first sketch some varieties of Uniqueness that appear in the literature. We then discuss some popular views that conflict with Uniqueness and others that require Uniqueness to be true. We then examine some arguments that have been presented in its favor and discuss why permissivists find them unconvincing. Last, we present some purported counterexamples that have been (...) raised against Uniqueness and discuss some possible reasons why proponents of Uniqueness might find these similarly unconvincing. (shrink)

Uniqueness appears to enhance intrinsic value. A unique stamp sells for millions of dollars; Stradivarius violins are all the more precious because they are unlike any others. This observation has not gone overlooked in the value theory literature: uniqueness plays a starring role recalibrating the dominant Moorean understanding of the nature of intrinsic value. But the thesis that uniqueness enhances intrinsic value is in tension with another deeply plausible and widely held thesis, namely the thesis that there (...) is a pro tanto reason to promote the good. It is argued that there is a second, distinct type of uniqueness that plays a more interesting and important axiological role: uniqueness imparts irreplaceable value. This gives occasion to develop the surprisingly undertheorized notion of irreplaceable value. (shrink)

We defend Uniqueness, the claim that given a body of total evidence, there is a uniquely rational doxastic state that it is rational for one to be in. Epistemic rationality doesn't give you any leeway in forming your beliefs. To this end, we bring in two metaepistemological pictures about the roles played by rational evaluations. Rational evaluative terms serve to guide our practices of deference to the opinions of others, and also to help us formulate contingency plans about what (...) to believe in various situations. We argue that Uniqueness vindicates these two roles for rational evaluations, while Permissivism clashes with them. (shrink)

In this paper I will show the problems that are encountered when dealing with uniqueness of connectives in a bilateralist setting within the larger framework of proof-theoretic semantics and suggest a solution. Therefore, the logic 2Int is suitable, for which I introduce a sequent calculus system, displaying - just like the corresponding natural deduction system - a consequence relation for provability as well as one dual to provability. I will propose a modified characterization of uniqueness incorporating such a (...) duality of consequence relations, with which we can maintain uniqueness in a bilateralist setting. (shrink)

This paper discusses the uniqueness thesis, a core thesis in the epistemology of disagreement. After presenting uniqueness and clarifying relevant terms, a novel counterexample to the thesis will be introduced. This counterexample involves logical disagreement. Several objections to the counterexample are then considered, and it is argued that the best responses to the counterexample all undermine the initial motivation for uniqueness.

By taking the practical relevance of coordinated epistemic standards into account, Dogramaci and Horowitz (2016) as well as Greco and Hedden (2016) offer a new perspective on epistemic permissiveness. However, in its current state, their argument appears to be inconclusive. I will offer two reasons why this argument does not support interpersonal uniqueness in general. First, such an argument leaves open the possibility that distinct closed societies come to incompatible epistemic standards. Second, some epistemic practices like the promotion of (...) methodological heterogeneity in epistemic communities could be best explained by epistemic permissiveness. (shrink)

A comparison is given between two conditions used to define logical constants: Belnap's uniqueness and Hacking's deducibility of identicals. It is shown that, in spite of some surface similarities, there is a deep difference between them. On the one hand, deducibility of identicals turns out to be a weaker and less demanding condition than uniqueness. On the other hand, deducibility of identicals is shown to be more faithful to the inferentialist perspective, permitting definition of genuinely proof-theoretical concepts. This (...) kind of analysis is driven by exploiting the Curry–Howard correspondence. In particular, deducibility of identicals is shown to correspond to the computational property of eta expansion, which is essential in the characterization of propositional identity. (shrink)

There is a divide in epistemology between those who think that, for any hypothesis and set of total evidence, there is a unique rational credence in that hypothesis, and those who think that there can be many rational credences. Schultheis offers a novel and potentially devastating objection to Permissivism, on the grounds that Permissivism permits dominated credences. I will argue that Permissivists can plausibly block Schultheis' argument. The issue turns on getting clear about whether we should be certain whether our (...) credences are rational. (shrink)

Conciliationism holds that disagreement of apparent epistemic peers often substantially undermines rational confidence in our opinions. Uniqueness principles say that there is at most one maximally rational doxastic response to any given batch of total evidence. The two views are often thought to be tightly connected. This paper distinguishes two ways of motivating conciliationism, and two ways that conciliationism may be undermined by permissive accounts of rationality. It shows how conciliationism can flourish under certain strongly permissive accounts of rationality. (...) This occurs when the motivation for conciliationism does not come from taking disagreement as evidence of one's own rational failings. However, divorcing the motive for conciliating from worries about rationality does not remove a feature of conciliationism that some find troubling: that conciliationism can lead to cases of “rational toxicity,” in which the most rational response to one's evidence involves violating some rational ideal. (shrink)

White, Christensen, and Feldman have recently endorsed uniqueness, the thesis that given the same total evidence, two rational subjects cannot hold different views. Kelly, Schoenfield, and Meacham argue that White and others have at best only supported the weaker, merely intrapersonal view that, given the total evidence, there are no two views which a single rational agent could take. Here, we give a new argument for uniqueness, an argument with deliberate focus on the interpersonal element of the thesis. (...) Our argument is that the best explanation of the value of promoting rationality is an explanation that entails uniqueness. (shrink)

It is widely agreed that hypocrisy can undermine one’s moral standing to blame. According to the Nonhypocrisy Condition on standing, R has the standing to blame some other agent S for a violation of some norm N only if R is not hypocritical with respect to blame for violations of N. Yet this condition is seldom argued for. Macalester Bell points out that the fact that hypocrisy is a moral fault does not yet explain why hypocritical blame is standingless blame. (...) She raises a challenge: one must explain what is distinct about hypocritical blame such that the hypocritical blamer lacks the standing to blame, even if the arrogant or petty blamer does not. Of those writing on hypocrisy, only we offer a direct response to Bell’s challenge. Recently, however, our account has come under criticism. We argue here that (1) our account can handle these criticisms and that (2) no other rival account adequately addresses Bell’s challenge of explaining what is uniquely objectionable about hypocritical blame. Because answering Bell’s challenge is a necessary component of any plausible account of the relationship between hypocrisy and standing, our account remains the best on offer. (shrink)

The A-theory and the B-theory advance competing claims about how time is grounded. The A-theory says that A-facts are more fundamental in grounding time than are B-facts, and the B-theory says the reverse. We argue that whichever theory is true of the actual world is also true of all possible worlds containing time. We do this by arguing that time is uniquely groundable: however time is actually grounded, it is necessarily grounded in that way. It follows that if either the (...) A-theory or the B-theory is actually false, then it is necessarily false. (shrink)

Artificial neural networks and supervised learning have become an essential part of science. Beyond using them for accurate input-output mapping, there is growing attention to a new feature-oriented approach. Under the assumption that networks optimised for a task may have learned to represent and utilise important features of the target system for that task, scientists examine how those networks manipulate inputs and employ the features networks capture for scientific discovery. We analyse this approach, show its hidden caveats, and suggest its (...) legitimate use. We distinguish three things that scientists call a ‘feature’: parametric, diagnostic, and real-world features. The feature-oriented approach aims for real-world features by interpreting the former two, which also partially rely on the network. We argue that this approach faces a problem of non-uniqueness: there are numerous discordant parametric and diagnostic features and ways to interpret them. When the approach aims at novel discovery, scientists often need to choose between those options, but they lack the background knowledge to justify their choices. Consequentially, features thus identified are not promised to be real. We argue that they should not be used as evidence but only used instrumentally. We also suggest transparency in feature selection and the plurality of choices. (shrink)

The paper explicates unique events and investigates their epistemology. Explications of unique events as individuated, different, and emergent are philosophically uninteresting. Unique events are topics of why-questions that radically underdetermine all their potential explanations. Uniqueness that is relative to a level of scientific development is differentiated from absolute uniqueness. Science eliminates relative uniqueness by discovery of recurrence of events and properties, falsification of assumptions of why-questions, and methodological simplification e.g. by explanatory methodological reduction. Finally, an overview of (...) contemporary philosophical disputes that hinge on issues of uniqueness emphasizes its philosophical significance. (shrink)

Two theses figure centrally in work on the epistemology of disagreement: Equal Weight (‘EW’) and Uniqueness (‘U’). According to EW, you should give precisely as much weight to the attitude of a disagreeing epistemic peer as you give to your own attitude. U has it that, for any given proposition and total body of evidence, some doxastic attitude is the one the evidence makes rational (justifies) toward that proposition. Although EW has received considerable discussion, the case for U has (...) not been critically evaluated. Endorsing U, we argue, commits one to the highly controversial thesis that whatever fixes your rational attitudes can do so only by fixing what evidence you have. This commitment imposes a relatively demanding requirement on justified belief in U, one that we argue is not satisfied by what is currently the strongest available case for U, due to Roger White [2005]. Our challenge to U makes more trouble for its proponents than do the worries about U expressed by Gideon Rosen [2001] and Thomas Kelly [2010]. Moreover, if Kelly [2010] is correct in thinking that EW “carries with it a commitment to” U—a claim which we accept for reasons similar to Kelly’s but is beyond this paper’s scope (but see Ballantyne and Coffman [forthcoming])—then our challenge to U bears importantly on EW: to the extent that our challenge to U succeeds, EW also suffers. (shrink)

Most people would agree that adoption is a good thing for children in need of a family. Yet adoption is often considered a second best or even last resort for parents in making their families. Against this assumption, I explore the unique value of adoption for prospective parents. I begin with a criticism of the selective focus on the value of adoption for only those people using assisted reproductive technologies. I focus on the value of adoption for all prospective parents, (...) reflecting on non-relative, non-procreative adoptions. First, adoption can meet the important need that a child has for a family, whereas procreation creates rather than meets needs. Second, adoption provides a morally noble opportunity to extend to a stranger benefits usually withheld for one's genetic kin. As such, adoption offers a unique possibility in which impartial concern for an other can be the starting point for a lifetime of love and care. Finally, adoptions can have transformative power over adoptive parents’ conception of family and self. In highlighting the unique value of adoption, I aim to challenge the widespread assumption that adoption has second best status to procreation. Indeed adoption can exemplify the human potential for moral compassion and impartial concern for the needs of others. (shrink)

Various authors have recently argued that you cannot rationally stick to your belief in the face of known disagreement with an epistemic peer, that is, a person you take to have the same evidence and judgmental skills as you do. For, they claim, because there is but one rational response to any body of evidence, a disagreement with an epistemic peer indicates that at least one of you is not responding rationally to the evidence. Given that you take your peer (...) to have the same judgmental skills as you do, and thus regard her to be equally good at assessing the evidence as you are, you will have as much reason for thinking that it is you who is not responding rationally to the evidence as for thinking that it is her. You thus have reason for thinking that your belief on the disputed matter is not a rational response to the evidence. Hence, you cannot rationally stick to your belief. (shrink)

We prove a uniqueness theorem showing that, subject to certain natural constraints, all 'no collapse' interpretations of quantum mechanics can be uniquely characterized and reduced to the choice of a particular preferred observable as determine (definite, sharp). We show how certain versions of the modal interpretation, Bohm's 'causal' interpretation, Bohr's complementarity interpretation, and the orthodox (Dirac-von Neumann) interpretation without the projection postulate can be recovered from the theorem. Bohr's complementarity and Einstein's realism appear as two quite different proposals for (...) selecting the preferred determinate observable--either settled pragmatically by what we choose to observe, or fixed once and for all, as the Einsteinian realist would require, in which case the preferred observable is a 'beable' in Bell's sense, as in Bohm's interpretation (where the preferred observable is position in configuration space). (shrink)

The main goal of this paper is to investigate whether humans are unique in using tools and artifacts. Non-human animals exhibit some impressive instances of tool and artifact-use. Chimpanzees use sticks to get termites out of a mound, beavers build dams, birds make nests, spiders create webs, bowerbirds make bowers to impress potential mates, etc. There is no doubt that some animals modify and use objects in clever and sophisticated ways. But how does this relate to the way in which (...) humans make and use objects to achieve their goals? To answer this question, this paper first presents a taxonomy of artifacts, identifying four overlapping categories, namely embodied, perceptual, cognitive, and affective artifacts. It then discusses definitions of animal tool-use, arguing that we need a more liberal approach, one that goes beyond the use of tools that are embedded in occurrent perception-action cycles. This paper ends by analysing how instances of animal tool and artifact-use can be classified according to the four identified categories, concluding that some animals use embodied, perceptual, cognitive, and affective artifacts. In this sense, humans are thus not unique in the kinds of tools and artifacts we use. What is unique, however, is our unprecedented flexibility and openness to deeply incorporate a large variety of complex tools and artifacts into our embodied, perceptual, cognitive, and affective systems. (shrink)

The A-theory and the B-theory advance competing claims about how time is grounded. The A-theory says that A-facts are more fundamental in grounding time than are B-facts, and the B-theory says the reverse. We argue that whichever theory is true of the actual world is also true of all possible worlds containing time. We do this by arguing that time is uniquely groundable: however time is actually grounded, it is necessarily grounded in that way. It follows that if either the (...) A-theory or the B-theory is actually false, then it is necessarily false. (shrink)

Pascal Engel (2008) has insisted that a number of notable strategies for rejecting the knowledge norm of assertion are put forward on the basis of the wrong kinds of reasons. A central aim of this paper will be to establish the contrast point: I argue that one very familiar strategy for defending the knowledge norm of assertion—viz., that it is claimed to do better in various respects than its competitors (e.g. the justification and the truth norms)— relies on a presupposition (...) that is shown to be ultimately under motivated. That presupposition is the uniqueness thesis—that there is a unique epistemic rule for assertion, and that such a rule will govern assertions uniformly. In particular, the strategy I shall take here will be to challenge the sufficiency leg of the knowledge norm in a way that at the same time counts against Williamson’s (2000) own rationale for the uniqueness thesis. However, rather than to challenge the sufficiency leg of the knowledge norm via the familiar style of ‘expert opinion’ and, more generally, ‘second-hand knowledge’ cases (e.g. Lackey (2008)), a strategy that has recently been called into question by Benton (2014), I’ll instead advance a very different line of argument against the sufficiency thesis, one which turns on a phenomenon I call epistemic hypocrisy. (shrink)

Saunders & van Brakel argue, inter alia, that there is for the claim that there are four unique hues (red, green, blue, and yellow), and that there are two corresponding opponent processes. We argue that this is quite mistaken.

Intelligent neurotechnology is an emerging field that combines neurotechnologies like brain-computer interface (BCI) with artificial intelligence. This paper introduces a capability framework to assess the responsible use of intelligent BCI systems and provide practical ethical guidance. It proposes two tests, the threshold and flourishing tests, that BCI applications must meet, and illustrates them in a series of cases. After a brief introduction (Section 1), Section 2 sets forth the capability view and the two tests. It illustrates the threshold test using (...) examples from clinical medicine of BCI applications that enable patients with profound disabilities to function at a threshold level through computer mediation. Section 3 illustrates the flourishing test by exploring possible future applications of BCI involving neuroenhancements for healthy people, using examples adapted from research currently underway in the US military. Section 3 applies a capability lens to a complex case involving dual effects, both therapeutic and non-therapeutic, showing how the threshold and flourishing tests resolve the case. Section 4 replies to three objections: neurorights are the best tool for assessing BCI; the two tests are moving targets; and the analysis utilizes a capability view to do work it is not designed for. The paper concludes that a capability view offers unique advantages and gives practical guidance for evaluating the responsible use of present and future BCI applications. Extrapolating from our analysis may help guide other emerging technologies, such as germline gene editing, expected to impact central human capabilities. (shrink)

A distinction is made between moral indoctrination and instruction in ethics. It is argued that the legitimate and important field of computer ethics should not be permitted to become mere moral indoctrination. Computer ethics is an academic field in its own right with unique ethical issues that would not have existed if computer technology had not been invented. Several example issues are presented to illustrate this point. The failure to find satisfactory non-computer analogies testifies to the uniqueness of computer (...) ethics. Lack of an effective analogy forces us to discover new moral values, formulate new moral principles, develop new policies, and find new ways to think about the issues presented to us. For all of these reasons, the kind of issues presented deserve to be addressed separately from others that might at first appear similar. At the very least, they have been so transformed by computing technology that their altered form demands special attention. (shrink)

Abstract. The concept of human uniqueness has long played a central role within key interpretations of the hominid fossil record and within numerous theological understandings of the imago Dei. More recently, the status of humans as evolutionarily unique has come under strong criticism owing to the discovery of certain nonhuman hominids who, as language and culture-bearing beings, lived as contemporaries with early anatomically modern humans. Nevertheless, many scholars, including those in the field of religion and science, continue to interpret (...) the remains of these other hominids in light of empirically ungrounded implicit assumptions about human uniqueness, which the author calls “anthropocentrism of the gaps.” This paper argues that “anthropocentrism of the gaps” is philosophically unwarranted and thus should not be assumed by scholars in religion and science when evaluating contemporary findings in paleoanthropology. (shrink)

Wentzel van Huyssteen's book Alone in the World? provides a thoughtful and nuanced account of human evolution from a theological perspective. Not only does his work provide what is perhaps the only sustained theological reflection specifically on human evolution, but his working through of many of the issues, particularly on the image of God literature in theology, has few parallels. Despite this, I focus on what I consider to be several weaknesses of the text, including areas of theological method, theological (...) interpretation, and the central topic of human uniqueness. Addressing these weaknesses will, I propose, improve van Huyssteen's argument and lead in new and fruitful directions. (shrink)

For contractarians, justice is the result of a rational bargain. The goal is to show that the rules of justice are consistent with rationality. The two most important bargaining theories of justice are David Gauthier’s and those that use the Nash’s bargaining solution. I argue that both of these approaches are fatally undermined by their reliance on a symmetry condition. Symmetry is a substantive constraint, not an implication of rationality. I argue that using symmetry to generate uniqueness undermines the (...) goal of bargaining theories of justice. (shrink)

A response is given here to Benacerraf's (1965) non-uniqueness (or multiple-reductions) objection to mathematical platonism. It is argued that non-uniqueness is simply not a problem for platonism; more specifically, it is argued that platonists can simply embrace non-uniqueness—i.e., that one can endorse the thesis that our mathematical theories truly describe collections of abstract mathematical objects while rejecting the thesis that such theories truly describe unique collections of such objects. I also argue that part of the motivation for (...) this stance is that it dovetails with the correct response to Benacerraf's other objection to platonism, i.e., his (1973) epistemological objection. (shrink)

It is folklore that if a continuous function on a complete metric space has approximate roots and in a uniform manner at most one root, then it actually has a root, which of course is uniquely determined. Also in Bishop's constructive mathematics with countable choice, the general setting of the present note, there is a simple method to validate this heuristic principle. The unique solution even becomes a continuous function in the parameters by a mild modification of the uniqueness (...) hypothesis. Moreover, Brouwer's fan theorem for decidable bars turns out to be equivalent to the statement that, for uniformly continuous functions on a compact metric space, the crucial uniform “at most one” condition follows from its non-uniform counterpart. This classification in the spirit of the constructive reverse mathematics, as propagated by Ishihara and others, sharpens an earlier result obtained jointly with Berger and Bridges. (shrink)

According to Ernst Gombrich, cartoons provide us the chance to “study the use of symbols in a circumscribed context [and] find out what role the image may play in the household of our mind” (Gombrich 1973, 190). This paper looks at some underexplored implications and outcomes of Ernst Gombrich’s conceptual schemata when such a schemata is applied to cartoons. While we might easily avoid defamatory reference when picking out a subject in writing or speech, cartoon depictions, especially those unaccompanied by (...) speech bubbles or captions, often rely on a visual symbolism typified by the warping of some features the removal of others, and the manifestation of some visual trope or other, more easily lend themselves to defamatory reference. While harms to the referent are many in cases of defamatory cartoons, this paper focuses on the harms to the viewers of such cartoons by the depicter’s message and mode of representation, unique to the cartoon form. I will focus on the harms of misinformation of the viewer by the visual schemata (Gombrich 1960) present in certain cartoons, and the way this misinformative visual schemata (Ibid) may also restrict the possibility of conceptual revisions in its viewership. Harms of this kind come out uniquely in cartoons via norms of cartooning (as a particularly stylized and symbolic mode of visual representation) and the norms of interaction employed in the act of viewing a cartoon. As we’ll see in our case study of the infamous Jyllands Posten cartoons of Muhammad the Prophet, even in cases where a cartoon representation bears no visual similarity to its referent, viewers can easily and reliably pick out the referent by calling to mind, in our focal case, the defamatory stereotypes, stock figures and icons inextricably linked with the referent. I argue that the damage to viewers of these sorts of depictions lies not in the fact that the viewer manages to pick out the intended referent of the depiction but what tools they use to pick out the referent and how such tools of reference (mis)inform their understanding of the referent they’ve picked out. (shrink)

Despite the widespread acceptance of naturalism in many of the human sciences, discussions of the extent to which human beings are ‘unique’ are still common among philosophers and scientists. Cognitive ethologists and comparative psychologists often defend a standard view of this question by quoting Darwin’s famous claims in The Descent of Man that ‘there is no fundamental difference between man and the higher mammals in their mental faculties’ and that all the differences are ‘differences of degree, not of kind’ (Darwin (...) 1871: 35). (shrink)

Wentzel van Huyssteen's Gifford Lectures, published as Alone in the World? Human Uniqueness in Science and Theology, accomplish critical and constructive thinking about interdisciplinary reflection on science and religion and about the meaning of human uniqueness. One approach to discussion of van Huyssteen's text entails consideration of three issues: the contextual character of research on humans and animals, the difficult problem of defining uniqueness, and the important consequences of exploring human uniqueness. Evolutionary biology and primatology contribute (...) specific scientific insights. (shrink)

I present an argument against the thesis of Uniqueness and in favour of Permissivism. Counterexamples to Uniqueness are provided, based on ‘Safespot’ propositions – i.e. a proposition that is guaranteed to be true provided the subject adopts a certain attitude towards it. The argument relies on a plausible principle: (roughly stated) If S knows that her believing p would be a true belief, then it is rationally permitted for S to believe p. One motivation for denying this principle (...) – viz. opposition to ‘epistemic consequentialism’ – is briefly discussed. The principle is extended to cover degrees of belief and compared with a couple of other well-known constraints on rational degrees of belief. (shrink)

Persons are thought to have a special kind of value, often called "dignity," which, according to Kant, makes them both infinitely valuable and irreplaceably valuable. The author aims to identify what makes a person a person in a way that can explain both aspects of dignity. She considers five definitions of "person": (1) an individual substance of a rational nature (Boethius), (2) a self-conscious being (Locke), (3) a being with the capacity to act for ends (Kant), (4) a being with (...) the capacity to act for another (Kant), and (5) an incommunicably unique subject (Wojtyla). She argues that none is capable of grounding both aspects of dignity since they are incompatible kinds of value; it is impossible for the same thing to ground both. Human persons are infinitely valuable in virtue of shareable qualities of their nature, whereas they are irreplaceably valuable because of a nonqualitative feature of their personhood. (shrink)

The Uniqueness Thesis, or rational uniqueness, claims that a body of evidence severely constrains one’s doxastic options. In particular, it claims that for any body of evidence E and proposition P, E justifies at most one doxastic attitude toward P. In this paper I defend this formulation of the uniqueness thesis and examine the case for its truth. I begin by clarifying my formulation of the Uniqueness Thesis and examining its close relationship to evidentialism. I proceed (...) to give some motivation for this strong epistemic claim and to defend it from several recent objections in the literature. In particular I look at objections to the Uniqueness Thesis coming from considerations of rational disagreement (can’t reasonable people disagree?), the breadth of doxastic attitudes(can’t what is justified by the evidence encompass more than one doxastic attitude?), borderline cases and caution (can’t it be rational to be cautious and suspend judgment even when the evidence slightly supports belief?), vagueness (doesn’t the vagueness of justification spell trouble for the Uniqueness Thesis?), and degrees of belief (doesn’t a finegrained doxastic picture present additional problems for the Uniqueness Thesis?). (shrink)

A distinction is made between moral indoctrination and instruction in ethics. It is argued that the legitimate and important field of computer ethics should not be permitted to become mere moral indoctrination. Computer ethics is an academic field in its own right with unique ethical issues that would not have existed if computer technology had not been invented. Several example issues are presented to illustrate this point. The failure to find satisfactory non-computer analogies testifies to the uniqueness of computer (...) ethics. Lack of an effective analogy forces us to discover new moral values, formulate new moral principles, develop new policies, and find new ways to think about the issues presented to us. For all of these reasons, the kind of issues presented deserve to be addressed separately from others that might at first appear similar. At the very least, they have been so transformed by computing technology that their altered form demands special attention. (shrink)

It is well known that, in Peano arithmetic, there exists a formula Theor (x) which numerates the set of theorems. By Gödel's and Löb's results, we have that Theor (˹p˺) ≡ p implies p is a theorem ∼Theor (˹p˺) ≡ p implies p is provably equivalent to Theor (˹0 = 1˺). Therefore, the considered "equations" admit, up to provable equivalence, only one solution. In this paper we prove (Corollary 1) that, in general, if P (x) is an arbitrary formula built (...) from Theor (x), then the fixed-point of P (x) (which exists by the diagonalization lemma) is unique up to provable equivalence. This result is settled referring to the concept of diagonalizable algebra (see Introduction). (shrink)

We consider the problem of uniqueness of certain simultaneity structures in flat spacetime. Absolute simultaneity is specifiled to be a non-trivial equivalence relation which is invariant under the automorphism group Aut of spacetime. Aut is taken to be the identity-component of either the inhomogeneous Galilei group or the inhomogeneous Lorentz group. Uniqueness of standard simultaneity in the first, and absence of any absolute simultaneity in the second case are demonstrated and related to certain group theoretic properties. Relative simultaneity (...) with respect to an additional structure X on spacetime is specified to be a non-trivial equivalence relation which is invariant under the subgroup in Aut that stabilises X. Uniqueness of standard Einstein simultaneity is proven in the Lorentzian case when X is an inertial frame. We end by discussing the relation to previous work of others. (shrink)

In this paper, I aim to do three things. First, I introduce the distinction between the Uniqueness Thesis (U) and what I call the Conditional Uniqueness Thesis (U*). Second, I argue that despite their official advertisements, some prominent uniquers effectively defend U* rather than U. Third, some influential considerations that have been raised by the opponents of U misfire if they are interpreted as against U*. The moral is that an appreciation of the distinction between U and U* (...) helps to clarify the contours of the uniqueness debate and to avoid a good deal of talking past each other. (shrink)

I argue that an evolutionary adaptation for bodily mimesis, the volitional use of the body as a representational devise, is the “small difference” that gave rise to unique and yet pre-linguistic features of humanity such as imitation, pedagogy, intentional communication and the possibility of a cumulative, representational culture. Furthermore, it is this that made the evolution of language possible. In support for the thesis that speech evolved atop bodily mimesis and a transitional multimodal protolanguage, I review evidence for the extensive (...) presence of sound-symbolism in modern languages, for its psychological reality in adults, and for its contribution to language acquisition in children. On a meta-level, the argument is that dividing human cognitive-semiotic evolution into a sequence of stages is crucial for resolving classical dichotomies concerning human nature and language, which are both natural and cultural, both continuous with and discontinuous from those of animals. (shrink)

This dissertation proposes and defends a hybrid view I call Hybrid Impermissivism, which combines the following two theses: Moderate Uniqueness and Credal Permissivism. Moderate Uniqueness says that no evidence could justify both believing a proposition and its negation. However, on Moderate Uniqueness, evidence could justify both believing and suspending judgement on a proposition (hence the adjective “Moderate”). And Credal Permissivism says that more than one credal attitude could be justified on the evidence. Hybrid Impermissisim is developed into (...) a precise theory by using normative bridge principles on how rational belief and credence ought to interact. My overall conclusion is that Hybrid Impermissivism is a coherent, plausible, and conciliatory position and provides a correct characterisation of the requirements of evidence on doxastic attitudes . (shrink)

We prove the following main theorem: Let be an abstract elementary class satisfying the joint embedding and the amalgamation properties with no maximal models of cardinality μ. Let μ be a cardinal above the the Löwenheim‐Skolem number of the class. If is μ‐Galois‐stable, has no μ‐Vaughtian Pairs, does not have long splitting chains, and satisfies locality of splitting, then any two ‐limits over M, for, are isomorphic over M.

In this Handbook entry, I review how colour similarity spaces are constructed, first for physical sources of colour and secondly for colour as it is perceptually experienced. The unique hues are features of one of the latter constructions, due initially to Hering and formalized in the Swedish Natural Colour System. I review the evidence for a physiological basis for the unique hues. Finally, I argue that Tye's realist approach to the unique hues is a mistake.

Here we discuss the challenge posed by self-organization to the Darwinian conception of evolution. As we point out, natural selection can only be the major creative agency in evolution if all or most of the adaptive complexity manifest in living organisms is built up over many generations by the cumulative selection of naturally occurring small, random mutations or variants, i.e., additive, incremental steps over an extended period of time. Biological self-organization—witnessed classically in the folding of a protein, or in the (...) formation of the cell membrane—is a fundamentally different means of generating complexity. We agree that self-organizing systems may be fine-tuned by selection and that self-organization may be therefore considered a complementary mechanism to natural selection as a causal agency in the evolution of life. But we argue that if self-organization proves to be a common mechanism for the generation of adaptive order from the molecular to the organismic level, then this will greatly undermine the Darwinian claim that natural selection is the major creative agency in evolution. We also point out that although complex self-organizing systems are easy to create in the electronic realm of cellular automata, to date translating in silico simulations into real material structures that self-organize into complex forms from local interactions between their constituents has not proved easy. This suggests that self-organizing systems analogous to those utilized by biological systems are at least rare and may indeed represent, as pre-Darwinists believed, a unique ascending hierarchy of natural forms. Such a unique adaptive hierarchy would pose another major challenge to the current Darwinian view of evolution, as it would mean the basic forms of life are necessary features of the order of nature and that the major pathways of evolution are determined by physical law, or more specifically by the self-organizing properties of biomatter, rather than natural selection. (shrink)

In this essay, I present a straightforward counterexample to the Uniqueness Thesis, which holds, roughly speaking, that there is a unique rational response to any particular body of evidence.

This article seeks to provide some genetic perspectives on the question “Just How Special Are Humans—Really?” It begins with an introduction to how genetic variation can provide information about the past. It continues by discussing two ways in which genetic analyses has, on multiple occasions, shown that humans are less unique than we thought we are. We have a cognitive bias to toward thinking we are special. Our species has colonized an ecological niche not exploited by any other species on (...) our earth, but how much of our adaptation to that niche is cultural rather than genetic? (shrink)