In this paper we present a framework for the dynamic and automatic generation of novel knowledge obtained through a process of commonsense reasoning based on typicality-based concept combination. We exploit a recently introduced extension of a Description Logic of typicality able to combine prototypical descriptions of concepts in order to generate new prototypical concepts and deal with problem like the PET FISH (Osherson and Smith, 1981; Lieto & Pozzato, 2019). Intuitively, in the context of our application of this logic, (...) the overall pipeline of our system works as follows: given a goal expressed as a set of properties, if the knowledge base does not contain a concept able to fulfill all these properties, then our system looks for two concepts to recombine in order to extend the original knowledge based satisfy the goal. (shrink)

Inventing novel knowledge to solve problems is a crucial, creative, mechanism employed by humans, to extend their range of action. In this paper, we present TCL (typicality-based compositional logic): a probabilistic, non monotonic extension of standard Description Logics of typicality, and will show how this framework is able to endow artificial systems of a human-like, commonsense based, concept composition procedure that allows its employment in a number of applications (ranging from computational creativity to goal-based reasoning to recommender systems and (...) affective computing). -/- The framework relies on 3 main ingredients: a non monotonic extension of standard Description Logics (allowing to reason on exceptions to inheritance in standard knowledge bases) a probabilistic extension coming from the field of logic programming (the DISPONTE semantics) a cognitive heuristics known ad HEAD-Modifier determining preference rules for the inheritance mechanisms of the novel concepts to be generated via commonsense rules. -/- We report the obtained results and the lessons learned of this research path in the context of model-based AI applications. -/- . (shrink)

Theorists of aesthetic value since Hume have traditionally aimed to justify at least some comparative judgments of aesthetic value and to explain why we thereby have more reason to appreciate some aesthetic objects than others. I argue that three recent theories of aesthetic value—Thi Nguyen’s and Matthew Strohl’s engagement theories, Nick Riggle’s communitarian theory, and Dominic McIver Lopes’ network theory—face a challenge to carry out this explanatory task in a satisfactory way. I defend a monotonicity principle according to which the (...) strength of our aesthetic reasons to appreciate varies monotonically with aesthetic value and claim that these theories, because they do not respect the principle, are non-monotonic. If they cannot find a plausible way to preserve the link between the aesthetic goodness of an object and our aesthetic reasons to appreciate it, these non-monotonic theories should be rejected. (shrink)

Formal ontologies are nowadays widely considered a standard tool for knowledge representation and reasoning in the Semantic Web. In this context, they are expected to play an important role in helping automated processes to access information. Namely: they are expected to provide a formal structure able to explicate the relationships between different concepts/terms, thus allowing intelligent agents to interpret, correctly, the semantics of the web resources improving the performances of the search technologies. Here we take into account a problem (...) regarding Knowledge Representation in general, and ontology based representations in particular; namely: the fact that knowledge modeling seems to be constrained between conflicting requirements, such as compositionality, on the one hand and the need to represent prototypical information on the other. In particular, most common sense concepts seem not to be captured by the stringent semantics expressed by such formalisms as, for example, Description Logics (which are the formalisms on which the ontology languages have been built). The aim of this work is to analyse this problem, suggesting a possible solution suitable for formal ontologies and semantic web representations. The questions guiding this research, in fact, have been: is it possible to provide a formal representational framework which, for the same concept, combines both the classical modelling view (accounting for compositional information) and defeasible, prototypical knowledge ? Is it possible to propose a modelling architecture able to provide different type of reasoning (e.g. classical deductive reasoning for the compositional component and a non monotonic reasoning for the prototypical one)? We suggest a possible answer to these questions proposing a modelling framework able to represent, within the semantic web languages, a multilevel representation of conceptual information, integrating both classical and non classical (typicality based) information. Within this framework we hypothesise, at least in principle, the coexistence of multiple reasoning processes involving the different levels of representation. (shrink)

Robert Koons claims that my previous critique of his “new” cosmological argument is vitiated by confusion about the nature of defeasible argumentation.In response, I claim that Koons misrepresents—and perhaps misunderstands—the nature of my objections to his “new” cosmological argument. The main claims which I defend are: (1) that the move from a non-defeasible to a defeasible causal principle makes absolutely no difference to the success of the cosmological argument in which it is contained; and (2) that, since it is perfectly (...) well understood that non-theists have many reasons for rejecting the defeasible causal principle, it is pointless to claim that the move to a defeasible principle brings about a shift in the “burden of proof”. (Since some people may have forgotten—or may choose to ignore—the fact that non-theists do have reasons for rejecting the defeasible causal principle, I also provide a discussion of a modest sample of these reasons.). (shrink)

In the late summer of 1998, the authors, a cognitive scientist and a logician, started talking about the relevance of modern mathematical logic to the study of human reasoning, and we have been talking ever since. This book is an interim report of that conversation. It argues that results such as those on the Wason selection task, purportedly showing the irrelevance of formal logic to actual human reasoning, have been widely misinterpreted, mainly because the picture of logic current (...) in psychology and cognitive science is completely mistaken. We aim to give the reader a more accurate picture of mathematical logic and, in doing so, hope to show that logic, properly conceived, is still a very helpful tool in cognitive science. The main thrust of the book is therefore constructive. We give a number of examples in which logical theorizing helps in understanding and modeling observed behavior in reasoning tasks, deviations of that behavior in a psychiatric disorder (autism), and even the roots of that behavior in the evolution of the brain. (shrink)

This is part of an authors meets critics session on Daniel Star's wonderful book, Knowing Better. I discuss a potential problem with Kearns and Star's Reasons as Evidence thesis. The issue has to do with the difficulties we face is we treat normative reasons as evidence and impose no possession conditions on evidence. On such a view, it's hard to see how practical reasoning could be a non-monotonic process. One way out of the difficulty would be to allow for (...) (potent) unpossessed reasons but insist that all evidence is possessed evidence. This option, I argue, isn't open to proponents of the Reasons as Evidence thesis. Instead, it seems that they'll have to say that all normative reasons are identified with pieces of possessed evidence. This requires the proponents of the Reasons as Evidence thesis to impose epistemic constraints on norms that some of us find objectionable. (shrink)

Reasoning over our knowledge bases and theories often requires non-deductive inferences, especially – but by no means only – when commonsense reasoning is the case, i.e. when practical agency is called for. This kind of reasoning can be adequately formalized via the notion of supraclassical consequence, a non-deductive consequence tightly associated with default and non-monotonic reasoning and featuring centrally in abductive, inductive, and probabilistic logical systems. In this paper, we analyze core concepts and problems of these (...) systems in the light of supraclassical consequence. (shrink)

Inventing novel knowledge to solve problems is a crucial, creative, mechanism employed by humans, to extend their range of action. In this talk, I will show how commonsense reasoning plays a crucial role in this respect. In particular, I will present a cognitively inspired reasoning framework for knowledge invention and creative problem solving exploiting TCL: a non-monotonic extension of a Description Logic (DL) of typicality able to combine prototypical (commonsense) descriptions of concepts in a human-like fashion. The proposed (...) approach has been tested both in the task of goal-driven concept invention and has additionally applied within the context of serendipity-based recommendation systems. I will present the obtained results, the lessons learned, and the road ahead of this research path. (shrink)

Logic has been a—disputed—ingredient in the emergence and development of the now very large field known as knowledge representation and reasoning. In this book (in progress), I select some central topics in this highly fruitful, albeit controversial, association (e.g., non-monotonic reasoning, implicit belief, logical omniscience, closed world assumption), identifying their sources and analyzing/explaining their elaboration in highly influential published work.

This paper discusses some key connexive principles construed as principles about reasons, that is, as principles that express logical properties of sentences of the form ‘_p_ is a reason for _q_’. Its main goal is to show how the theory of reasons outlined by Crupi and Iacona, which is based on their evidential account of conditionals, yields a formal treatment of such sentences that validates a restricted version of the principles discussed, overcoming some limitations that affect most extant accounts of (...) conditionals. (shrink)

Some believe that all arguments make an implicit “inference claim” that the conclusion is inferable from the premises (e.g., Bermejo-Luque, Grennan, the Groarkes, Hitchcock, Scriven). I try to show that this is confused. An act of arguing arises because an inference can be attributed to us, not a meta-level “inference claim” that would make the argument self-referential and regressive. I develop six (other) possible explanations of the popularity of the doctrine that similarly identify confusions.

Dynamic conceptual reframing represents a crucial mechanism employed by humans, and partially by other animal species, to generate novel knowledge used to solve complex goals. In this talk, I will present a reasoning framework for knowledge invention and creative problem solving exploiting TCL: a non-monotonic extension of a Description Logic (DL) of typicality able to combine prototypical (commonsense) descriptions of concepts in a human-like fashion [1]. The proposed approach has been tested both in the task of goal-driven concept invention (...) [2,3] and has additionally applied within the context of serendipity-based recommendation systems [4]. I will present the obtained results, the lessons learned, and the road ahead of this research path. -/- . (shrink)

This paper investigates the logic of reasons. Its aim is to provide an analysis of the sentences of the form ‘p is a reason for q’ that yields a coherent account of their logical properties. The idea that we will develop is that ‘p is a reason for q’ is acceptable just in case a suitably defined relation of incompatibility obtains between p and ¬q. As we will suggest, a theory of reasons based on this idea can solve three challenging (...) puzzles that concern, respectively, contraposing reasons, conflicting reasons, and supererogatory reasons, and opens a new perspective on some classical issues concerning non-deductive inferences. (shrink)

Inferentialism, especially Brandom’s theory, is the project aimed at understanding meaning as determined by inferences, and language as a social practice governed by rational discursive norms. Discursive practice is thus understood as the basic rational practice, where commitments undertaken by participants are evaluated in terms of their being correct/incorrect. This model of explanation is also intended to rescue, by means of reasons, the commitments we undertake ourselves and assess the commitments we attribute to others, in an objective sense: starting from (...) our subjective normative and doxastic attitudes we should be able to use the normative discursive resources apt to assess our commitments, not only referring to what we take to be correct, but also referring to how things actually are.My hypothesis is that this objectivity is not achieved only on the basis of the rational structure of discursive practice. The main worry concerns the fact that material inferences, those responsible for the content of our concepts (and commitments), are in general non-monotonic. These inferences put experts in an advantageous position,namely as those capable of defeasible reasoning. I propose a view by which this asymmetry among language users is the crucial factor in assessing the objectivity of claims within discursive practice. (shrink)

This paper presents a uniform semantic treatment of nonmonotonic inference operations that allow for inferences from infinite sets of premises. The semantics is formulated in terms of selection functions and is a generalization of the preferential semantics of Shoham (1987), (1988), Kraus, Lehman, and Magidor (1990) and Makinson (1989), (1993). A selection function picks out from a given set of possible states (worlds, situations, models) a subset consisting of those states that are, in some sense, the most preferred ones. A (...) proposition α is a nonmonotonic consequence of a set of propositions Γ iff α holds in all the most preferred Γ-states. In the literature on revealed preference theory, there are a number of well-known theorems concerning the representability of selection functions, satisfying certain properties, in terms of underlying preference relations. Such theorems are utilized here to give corresponding representation theorems for nonmonotonic inference operations. At the end of the paper, the connection between nonmonotonic inference and belief revision, in the sense of Alchourrón, Gärdenfors, and Makinson, is explored. In this connection, infinitary belief revision operations that allow for the revision of a theory with a possibly infinite set of propositions are introduced and characterized axiomatically. (shrink)

Invited Lecture at the SRM ACM Student Chapter, India, on Cognitive Heuristics for Commonsense Thinking and Reasoning in the next generation Artificial Intelligence. The lecture proposes a historical and technical overview of strategies for commonsense reasoning in AI.

I discuss Smokrović’s work on the normativity of logic (Smokrović 2017, Smokrović 2018). I agree that the classical formal logic is not an adequate model for real-life reasoning. But I present some doubts about his notion of deductive logic and his proposal to model such reasoning in non-monotonic logic. No branch of formal logic by itself is likely to capture real-life inferential links (reasoned-inference). I use the logic of relevance as my case study and extend the pessimistic morals (...) to modern systems of non-classical logic. Finally, I propose a more lax conception of normativty: there is a connection between logical assessment in the broad sense (as sanctioned by the notion of cogency) and the evaluation and criticism of reasoning. (shrink)

I present a possible worlds semantics for a hyperintensional belief revision operator, which reduces the logical idealization of cognitive agents affecting similar operators in doxastic and epistemic logics, as well as in standard AGM belief revision theory. (Revised) belief states are not closed under classical logical consequence; revising by inconsistent information does not perforce lead to trivialization; and revision can be subject to ‘framing effects’: logically or necessarily equivalent contents can lead to different revisions. Such results are obtained without resorting (...) to non-classical logics, or to non-normal or impossible worlds semantics. The framework combines, instead, a standard semantics for propositional S5 with a simple mereology of contents. (shrink)

In this paper we propose a computational framework aimed at extending the problem solving capabilities of cognitive artificial agents through the introduction of a novel, goal-directed, dynamic knowledge generation mechanism obtained via a non monotonic reasoning procedure. In particular, the proposed framework relies on the assumption that certain classes of problems cannot be solved by simply learning or injecting new external knowledge in the declarative memory of a cognitive artificial agent but, on the other hand, require a mechanism for (...) the automatic and creative re-framing, or re-formulation, of the available knowledge. We show how such mechanism can be obtained trough a framework of dynamic knowledge generation that is able to tackle the problem of commonsense concept combination. In addition, we show how such a framework can be employed in the field of cognitive architectures in order to overcome situations like the impasse in SOAR by extending the possible options of its subgoaling procedures. (shrink)

Are non-natural properties worth caring about? I consider two objections to metaethical non-naturalism. According to the intelligibility objection, it would be positively unintelligible to care about non-natural properties that float free from the causal fabric of the cosmos. According to the ethical idlers objection, there is no compelling motivation to posit non-natural normative properties because the natural properties suffice to provide us with reasons. In both cases, I argue, the objection stems from misunderstanding the role that non-natural properties play in (...) the non-naturalist's understanding of normativity. The role of non-natural properties is not to be responded to, but to "mark" which natural properties it is correct for us to respond to in certain ways. (shrink)

In Liberalism without Perfection, Jonathan Quong develops what is perhaps the most comprehensive defense of the consensus model of public reason – a model which incorporates both a public-reasons-only requirement and an accessibility requirement framed in terms of shared evaluative standards. While the consensus model arguably predominates amongst public reason liberals, it is criticized by convergence theorists who reject both the public-reasons-only requirement and the accessibility requirement. In this paper, I argue that while we have good reason to reject Quong’s (...) call for a public-reasons-only requirement, all public reason liberals should endorse at least some shared evaluative standards and, hence, an accessibility requirement. (shrink)

In previous work, we studied four well known systems of qualitative probabilistic inference, and presented data from computer simulations in an attempt to illustrate the performance of the systems. These simulations evaluated the four systems in terms of their tendency to license inference to accurate and informative conclusions, given incomplete information about a randomly selected probability distribution. In our earlier work, the procedure used in generating the unknown probability distribution (representing the true stochastic state of the world) tended to yield (...) probability distributions with moderately high entropy levels. In the present article, we present data charting the performance of the four systems when reasoning in environments of various entropy levels. The results illustrate variations in the performance of the respective reasoning systems that derive from the entropy of the environment, and allow for a more inclusive assessment of the reliability and robustness of the four systems. (shrink)

In this paper, I discuss the analysis of logic in the pragmatic approach recently proposed by Brandom. I consider different consequence relations, formalized by classical, intuitionistic and linear logic, and I will argue that the formal theory developed by Brandom, even if provides powerful foundational insights on the relationship between logic and discursive practices, cannot account for important reasoning patterns represented by non-monotonic or resource-sensitive inferences. Then, I will present an incompatibility semantics in the framework of linear logic which (...) allow to refine Brandom’s concept of defeasible inference and to account for those non-monotonic and relevant inferences that are expressible in linear logic. Moreover, I will suggest an interpretation of discursive practices based on an abstract notion of agreement on what counts as a reason which is deeply connected with linear logic semantics. (shrink)

We present two defeasible logics of norm-propositions (statements about norms) that (i) consistently allow for the possibility of normative gaps and normative conflicts, and (ii) map each premise set to a sufficiently rich consequence set. In order to meet (i), we define the logic LNP, a conflict- and gap-tolerant logic of norm-propositions capable of formalizing both normative conflicts and normative gaps within the object language. Next, we strengthen LNP within the adaptive logic framework for non-monotonic reasoning in order to (...) meet (ii). This results in the adaptive logics LNPr and LNPm, which interpret a given set of premises in such a way that normative conflicts and normative gaps are avoided ‘whenever possible’. LNPr and LNPm are equipped with a preferential semantics and a dynamic proof theory. (shrink)

This is a first tentative examination of the possibility of reinstating reduction as a valid candidate for presenting relations between mental and physical properties. Classical Nagelian reduction is undoubtedly contaminated in many ways, but here I investigate the possibility of adapting to problems concerning mental properties an alternative definition for theory reduction in philosophy of science. The definition I offer is formulated with the aid of non-monotonic logic, which I suspect might be a very interesting realm for testing notions concerning (...) localized mental-physical reduction. The reason for this is that non-monotonic reasoning by definition is about appeals made not only to explicit observations, but also to an implicit selection of background knowledge containing heuristic information. The flexibility of this definition and the fact that it is not absolute, i.e. that the relation of reduction may be retracted or allowed to shift without fuss, add at least an interesting alternative factor to current materialist debates. South African Journal of Philosophy Vol. 25(2) 2006: 102-112. (shrink)

Most formalisms for representing common-sense knowledge allow incomplete and potentially inconsistent information. When strong negation is also allowed, contradictory conclusions can arise. A criterion for deciding between them is needed. The aim of this paper is to investigate an inherent and autonomous comparison criterion, based on specificity as defined in [POO 85, SIM 92]. In contrast to other approaches, we consider not only defeasible, but also strict knowledge. Our criterion is context-sensitive, i. e., preference among defeasible rules is determined dynamically (...) during the dialectical analysis.We show how specificity can be defined in terms of two different approaches: activation sets and derivation trees. This allows us to get a syntactic criterion that can be implemented in a computationally attractive way. The resulting definitions may be applied in general rulebased formalisms. We present theorems linking both characterizations. Finally we discuss other frameworks for defeasible reasoning in which preference handling is considered explicitly. (shrink)

In questo contributo descriviamo un sistema di creatività computazionale in grado di generare automaticamente nuovi concetti utilizzando una logica descrittiva non monotòna che integra tre ingredienti principali: una logica descrittiva della tipicalità, una estensione probabilistica basata sulla semantica distribuita nota come DISPONTE, e una euristica di ispirazione cognitiva per la combinazione di più concetti. Una delle applicazioni principali del sistema riguarda il campo della creatività computazionale e, più specificatamente, il suo utilizzo come sistema di supporto alla creatività in ambito mediale. (...) In particolare, tale sistema è in grado di: generare nuove storie (a partire da una rappresentazione narrativa di storie pre-esistenti), generare nuovi personaggi (ad es. il nuovo “cattivo” di una serie tv o di un cartone animato) e, in generale, può essere utilizzato per proporre nuove soluzioni e format narrativi da esplorare nell’ambito dell’industria creativa. (shrink)

Default logic has been a very active research topic in artificial intelligence since the early 1980s, but has not received as much attention in the philosophical literature thus far. This paper shows one way in which the technical tools of artificial intelligence can be applied in contemporary epistemology by modeling a paradigmatic case of deep disagreement using default logic. In §1 model-building viewed as a kind of philosophical progress is briefly motivated, while §2 introduces the case of deep disagreement we (...) aim to model. On the heels of this, §3 defines our formal framework, viz., a refined Horty-style default logic. §4 then uses the framework to model deep disagreement, and finally §5 provides a critical discussion of the result. (shrink)

Even if the “value-free ideal of science” (VFI) were an unattainable goal, one could ask: can it be a useful fiction, one that is beneficial for the research community and society? This question is particularly crucial for scholars and institutions concerned with research integrity (RI), as one cannot offer normative guidance to researchers without making some assumptions about what ideal scientific research looks like. Despite the insofar little interaction between scholars studying RI and those working on values in science, the (...) overlap of topics and interests make collaboration between the two fields promising for understanding research and its ethics. Here, we identify—for the use of RI scholars—the non-epistemic reasons (societal, political, professional) for and against the VFI considered in the literature. All of these are concerned with the beneficial or detrimental consequences that endorsing the VFI would have on society, policy-making, or the scientific community, with some authors appealing to the same principles to argue for opposite positions. Though most of the reviewed articles do not endorse the VFI, it is generally agreed that some constraints have to be put on the use of non-epistemic values. Disagreement on the utility of the VFI lies both on the different epistemic-descriptive positions taken by different authors, and on the scarcity of relevant empirical studies. Engaging critically with the reasons here identified and more in general with the values in science debate will help the RI community decide whether the VFI should be included in future codes of conduct. (shrink)

BACKGROUND: -/- Preconception sex selection for non-medical reasons raises serious moral, legal and social issues. The main concern is based on the assumption that a freely available service for sex selection will distort the natural sex ratio and lead to a severe gender imbalance. However, for a severe gender imbalance to happen, at least two conditions have to be met. First, there must be a significant preference for children of a particular sex, and second, there must be a considerable demand (...) for preconception sex selection. To ascertain whether or not these two conditions are met, we have conducted a survey in Germany. METHODS: -/- As a representative sample of the German population, 1094 men and women aged 18-45 years were asked about their gender preferences and whether or not they could imagine selecting the sex of their children through flow cytometric separation of X- and Y-bearing sperm followed by intrauterine insemination. RESULTS: -/- 58% of respondents stated that they do not care about the sex of their offspring. 30% wish to have a family with an equal number of boys and girls. 4% would like to have more boys than girls, 3% more girls than boys, 1% only boys and 1% only girls. For first-borns, however, there is still a preference for boys over girls. While 75.6% claimed to have no gender preference, 14.2% would like their first child to be a boy and 10.1% would like their first child to be a girl. Whereas 6% could imagine taking advantage of preconception sex selection, 92% found this to be out of the question. Even in the hypothetical case that a medication for sex selection were ever to become available, 90% stated that they would not want to use it. CONCLUSION: -/- Given that a majority does not seem to care about the sex of their offspring and only a minority seem to be willing to select the sex of their children, a freely available service for preconception sex selection for non-medical reasons is rather unlikely to cause a severe gender imbalance in Germany. (shrink)

This paper develops a trivalent semantics for the truth conditions and the probability of the natural language indicative conditional. Our framework rests on trivalent truth conditions first proposed by Cooper (1968) and Belnap (1973) and it yields two logics of conditional reasoning: (i) a logic C of certainty-preserving inference; and (ii) a logic U for uncertain reasoning that preserves the probability of the premises. We show systematic correspondences between trivalent and probabilistic representations of inferences in either framework, and (...) we use the distinction between the two systems to cast light on the validity of inferences such as Modus Ponens, Or-To-If, and Conditional Excluded Middle. Specifically, the conditional behaves monotonically in C, but non-monotonically in U; Modus Ponens is valid in C, but valid in U only for non-nested conditionals. The result is a unified account of the semantics and epistemology of indicative conditionals that can be fruitfully applied to analyzing the validity of conditional inferences. (shrink)

In Public Reason Confucianism, Kim Sungmoon presents a perfectionist theory that is based on a partially comprehensive Confucian doctrine but is non-sectarian, since the doctrine is widely shared in East Asian societies. Despite its attractiveness, I argue that this project, unfortunately, fails because it is still vulnerable to the sectarian critique. The blurred distinction between partially and fully comprehensive doctrines will create a loophole problem. Sectarian laws and policies may gain legitimacy that they do not deserve. I further defend political (...) Confucianism, which is regarded by Kim as an inadequately intelligible form of Confucianism. Kim assumes a too narrow understanding of intelligibility. Although political Confucianism may not be politically intelligible, it is civically intelligible, i.e. it is culturally intelligibly different from other political theories in terms of its implications in citizens’ actions in civil society. In light of civic intelligibility, the distinctiveness of political Confucianism should not be underestimated. (shrink)

How is it possible that beginning from the negation of rational thoughts one comes to produce knowledge? This problem, besides its intrinsic interest, acquires a great relevance when the representation of a knowledge is settled, for example, on data and automatic reasoning. Many treatment ways have been tried, as in the case of the non-monotonic logics; logics that intend to formalize an idea of reasoning by default, etc. These attempts are incomplete and are subject to failure. A possible (...) solution would be to formulate a logic of the irrational, which offers a model for reasoning permitting to support contradictions as well as to produce knowledge from such situations. An intuition underlying the foundation of such a logic consists of the da Costa's paraconsistent logics presenting however, a different deduction theory and a whole distinct semantics, called here "the semantics of possible translations". The present proposing, following our argumentation, intends to enlight all this question, by a whole satisfactory logical point of view, being practically applicable and philosophically acceptable.Como é possível que a partir da negação do racional se possa obter conhecimento adicional? Esse problema, além de seu interesse intrínseco, adquire uma relevância adicional quando o encontramos na representação do conhecimento em bases de dados e raciocínio automático, por exemplo. Nesse caso, diversas tentativas de tratamento têm sido propostas, como as lógicas não-monotônicas, as lógicas que tentam formalizar a ideia do raciocínio por falha . Tais tentativas de solução, porém, são falhas e incompletas; proponho que uma solução possível seria formular uma lógica do irracional, que oferecesse um modelo para o raciocínio permitindo não só suportar contradições, como conseguir obter conhecimento, a partir de tais situações. A intuição subjacente à formulação de tal lógica são as lógicas paraconsistentes de da Costa, mas com uma teoria da dedução diferente e uma semântica completamente distinta . Tal proposta, como pretendo argumentar, fornece um enfoque para a questão que é ao mesmo tempo completamente satisfatório, aplicável do ponto de vista prático e aceitável do ponto de vista filosófico. (shrink)

Which principles govern the transmission of reasons from ends to means? Some philosophers have suggested a liberal transmission principle, according to which agents have an instrumental reason for an action whenever this action is a means for them to do what they have non-instrumental reason to do. In this paper, we (i) discuss the merits and demerits of the liberal transmission principle, (ii) argue that there are good reasons to reject it, and (iii) present an alternative, less liberal transmission principle, (...) which allows us to accommodate those phenomena that seem to support the liberal transmission principle while avoiding its problems. (shrink)

Many believe that, if true, reason-statements of the form ‘that X is F is a reason to φ’ describe a ‘favouring-relation’ between the fact that X is F and the act of φing. This favouring-relation has been assumed to share many features of other, more concrete relations. This combination of views leads to immediate problems. Firstly, unlike statements about many other relations, reason-statements can be true even when the relata do not exist, i.e., when the relevant facts do not obtain (...) and the relevant acts are not done. Secondly, the previous combination of views also makes it very difficult to draw the distinction between agent-relative and agent-neutral reasons. I argue that we should think that the predicate ‘is a reason to’ creates non-extensional contexts in the statements in which it is used. This would both solve the previous problems and avoid the awkward consequences of the so-called slingshot argument. (shrink)

If a conclusion was reached that creatures without a language capability exhibit some form of a capability for logic, this would shed a new light on the relationship between logic, language, and thought. Recent experimental attempts to test whether some animals, as well as pre-linguistic human infants, are capable of exclusionary reasoning are taken to support exactly that conclusion. The paper discusses the analyses and conclusions of two such studies: Call’s (2004) two cups task, and Mody and Carey’s (2016) (...) four cups task. My paper exposes hidden assumptions within these analyses, which enable the authors to settle on the explanation which assigns logical capabilities to the participants of the studies, as opposed to the explanations which do not. The paper then demonstrates that the competing explanations of the experimental results are theoretically underdeveloped, rendering them unclear in their predictions concerning the behavior of cognitive subjects, and thus difficult to distinguish by use of experiments. Additionally, it is questioned whether the explanations are rivals at all, i.e. whether they compete to explain the cognitive processes of the same level. The contribution of the paper is conceptual. Its aim is to clear up the concepts involved in these analyses, in order to avoid oversimplified or premature conclusions about the cognitive abilities of pre- and non-linguistic creatures. It is also meant to show that the theoretical space surrounding the issues involved might be much more diverse and unknown than many of these studies imply. (shrink)

According to Cian Dorr, non-cognitivism has the implausible implication that arguments like the following are cases of wishful thinking: If lying is wrong, then the souls of liars will be punished in the afterlife; lying is wrong; therefore, the souls of liars will be punished in the afterlife. Dorr further claims that if non-cognitivism implies that the above argument and similar arguments are cases of wishful thinking, then non-cognitivism remains implausible even if one solves the so-called Frege-Geach problem. Dorr’s claims (...) have faced a number of objections, but I believe that Dorr is on to something. So, after summarizing Dorr’s argument and briefly describing three flaws in what Dorr claims, I shall present a distinct objection to non-cognitivism and use the preceding to show what Dorr’s argument gets right and what it gets wrong. (shrink)

Graham Priest has formulated the minimally inconsistent logic of paradox (MiLP), which is paraconsistent like Priest’s logic of paradox (LP), while staying closer to classical logic. We present logics that stand to (the propositional fragments of) strong Kleene logic (K3) and the logic of first-degree entailment (FDE) as MiLP stands to LP. That is, our logics share the paracomplete and the paraconsistent-cum-paracomplete nature of K3 and FDE, respectively, while keeping these features to a minimum in order to stay closer to (...) classical logic. We give semantic and sequent-calculus formulations of these logics, and we highlight some reasons why these logics may be interesting in their own right. (shrink)

One way to approach the question of whether there are non-derivative partial reasons of any kind is to give an account of what partial reasons are, and then to consider whether there are such reasons. If there are, then it is at least possible that there are partial reasons of friendship. It is this approach that will be taken here, and it produces several interesting results. The first is a point about the structure of partial reasons. It is at least (...) a necessary condition of a reason’s being partial that it has an explicit relational component. This component, technically, is a rela- tum in the reason relation that itself is a relation between the person to whom the reason applies and the person whom the action for which there is a reason concerns. The second conclusion of the paper is that this relational component is also required for a number of types of putatively impartial reasons. In order to avoid trivialising the distinction between partial and impartial rea- sons, some further sufficient condition must be applied. Finally, there is some prospect for a way of distinguishing between impartial reasons that contain a relational component and partial rea- sons, but that this approach suggests that the question of whether ethics is partial or impartial will be settled at the level of normative ethical discourse, or at least not at the level of discourse about the nature of reasons for action. (shrink)

This paper offers a sketch of welfarist pluralism, a view that is intended to resolve a difficulty for non-derivative pluralists about normative reasons for belief. Welfarist pluralism is the view that all reasons for belief are rooted in wellbeing, and that wellbeing has as one of its components being in a positive epistemic state. The paper explores how this view can explain various pluralist intuitions and why it offers a plausible basis for combinatorial pluralists who believe that alethic and pragmatic (...) reasons for belief combine to determine what one ought to believe. The paper also considers the relationship between theoretical rationality and wellbeing, and provides a partial argument for the derivative normativity of at least some requirements of theoretical rationality. (shrink)

Recent work in cognitive modelling has found that most of the data that has been cited as evidence for the dual-process theory (DPT) of reasoning is best explained by non-linear, “monotonic” one-process models (Stephens et al., 2018, 2019). In this paper, I consider an important caveat of this research: it uses models that are committed to unrealistic assumptions about how effectively task conditions can isolate Type-1 and Type-2 reasoning. To avoid this caveat, I develop a coordinated theoretical, experimental, (...) and modelling strategy to better test DPT. First, I propose that Type-1 and Type-2 reasoning are defined as reasoning that precedes and follows metacognitive control, respectively. Second, I argue that reasoning that precedes and follows metacognitive control can be effectively isolated using debiasing paradigms that manipulate metacognitive heuristics (e.g., processing fluency) to prevent or trigger metacognitive control, respectively. Third, I argue that monotonic modelling can allow us to decisively test DPT only when we use them to analyse data from this particular kind of debiasing paradigm. (shrink)

Normal interpersonal treatment is often based on the existence of the rational nature of both the agent and the target of the treatment, and their relationship is reciprocal and mutual. However, when the rational person confronts the irrational person, such as the mentally retarded or vegetative person, the reciprocal relationship cannot be maintained because the targeted person loses his or her rational capacity. But this inequality does not deprive the object of action of the right to be treated rationally, because (...) people treat the irrationally disabled not according to the principle of reason but according to the principle of emotion - specifically, the principle of love. The principle of love often disregards the specific conditions of the object of treatment and still treats them reasonably. Thus, the emotional principle has a broader application in interpersonal treatment. (shrink)

This paper outlines a new pluralistic theory of normative reasons for belief, welfarist pluralism, which aims to explain how there can be basic alethic/epistemic reasons for belief and basic pragmatic/non-alethic reasons for belief that can combine to determine what one ought to believe. The paper shows how this non-derivative first-order pluralism arises from a purely welfarist account of the foundations of theoretical normativity, thereby combining foundational pragmatism with non-derivative pluralism about normative reasons for belief. In addition, this paper outlines how (...) welfarist pluralism provides a new and potentialy attractive account of the value of truth (or its indicators), namely that the value of truth (or its indicators) is its direct contribution to individuals' personal good or wellbeing. (shrink)

Joseph Raz claims that there can be reason to do the impossible; but partial compliance with reason is better than non-compliance and the closer one gets to complying with reason, the better. I propose some exceptions.

Call a belief ”non-negotiable’ if one cannot abandon the belief without the abandonment of one’s religious perspective. Although non-negotiable beliefs can logically exclude other perspectives, a non-reductive approach to religious pluralism can help to create a space within which the non- negotiable beliefs of others that contradict one’s own non-negotiable beliefs can be appreciated and understood as playing a justificatory role for the other. The appreciation of these beliefs through cognitive resonance plays a crucial role to enable the understanding of (...) those who hold other perspectives. epistemological and spiritual consequences of this claim are explored. (shrink)

In the classic Miners case, an agent subjectively ought to do what they know is objectively wrong. This case shows that the subjective and objective ‘oughts’ are somewhat independent. But there remains a powerful intuition that the guidance of objective ‘oughts’ is more authoritative—so long as we know what they tell us. We argue that this intuition must be given up in light of a monotonicity principle, which undercuts the rationale for saying that objective ‘oughts’ are an authoritative guide for (...) agents and advisors. (shrink)

A non-embracing consequence relation is one such that no set of wffs closed under it is equal to the set of all wffs. I prove that these relations have no deductive power if they are also extensive and monotonic.

Non-moral blame seems to be widespread and widely accepted in everyday life—tolerated at least, but often embraced. We blame athletes for poor performance, artists for bad or boring art, scientists for faulty research, and voters for flawed reasoning. This paper argues that non-moral blame is never justified—i.e. it’s never a morally permissible response to a non-moral failure. Having explained what blame is and how non-moral blame differs from moral blame, the paper presents the argument in four steps. First, it (...) argues that many (perhaps most) apparent cases of non-moral blame are actually cases of moral blame. Second, it argues that even if non-moral blame is pro tanto permissible—because its target is blameworthy for their substandard performance—it often (perhaps usually) fails to meet other permissibility conditions, such as fairness or standing. Third, it goes further and challenges the claim that non-moral blame is ever even pro tanto permissible. Finally, it considers a number of arguments in support of non-moral obligations and argues that none of them succeed. (shrink)

We generalize, by a progressive procedure, the notions of conjunction and disjunction of two conditional events to the case of n conditional events. In our coherence-based approach, conjunctions and disjunctions are suitable conditional random quantities. We define the notion of negation, by verifying De Morgan’s Laws. We also show that conjunction and disjunction satisfy the associative and commutative properties, and a monotonicity property. Then, we give some results on coherence of prevision assessments for some families of compounded conditionals; in particular (...) we examine the Fréchet-Hoeffding bounds. Moreover, we study the reverse probabilistic inference from the conjunction Cn+1 of n + 1 conditional events to the family {Cn,En+1|Hn+1}. We consider the relation with the notion of quasi-conjunction and we examine in detail the coherence of the prevision assessments related with the conjunction of three conditional events. Based on conjunction, we also give a characterization of p-consistency and of p-entailment, with applications to several inference rules in probabilistic nonmonotonic reasoning. Finally, we examine some non p-valid inference rules; then, we illustrate by an example two methods which allow to suitably modify non p-valid inference rules in order to get inferences which are p-valid. (shrink)