Current research suggests that nonclinical forensic psychologists[sup1] are appearing increasingly more often in the legal arena. We argue that many of the ethical dilemmas that face these psychologists differ from those encountered by clinical forensic psychologists. To test the accuracy of this assertion, 37 nonclinical forensic psychologists were surveyed to identify some of the ethical issues and dilemmas they have encountered while engaging in expert testimony or pretrial consulting. Respondents were asked also about how they have resolved these ethical issues (...) and whether they were aware of the "Specialty Guidelines for Forensic Psychologists" (Committee on Ethical Guidelines for Forensic Psychologists, 1991). Results of the survey are discussed in terms of the need for additional regulatory guidelines or professional standards that speak directly to the ethical issues confronting nonclinical, forensic expert witnesses and consultants. (shrink)

Should we make significant sacrifices to ever-so-slightly lower the chance of extremely bad outcomes, or to ever-so-slightly raise the chance of extremely good outcomes? *Fanaticism* says yes: for every bad outcome, there is a tiny chance of extreme disaster that is even worse, and for every good outcome, there is a tiny chance of an enormous good that is even better. I consider two related recent arguments for Fanaticism: Beckstead and Thomas's argument from *strange dependence on space and time*, and (...) Wilkinson's *Indology* argument. While both arguments are instructive, neither is persuasive. In fact, the general principles that underwrite the arguments (a *separability* principle in the first case, and a *reflection* principle in the second) are *inconsistent* with Fanaticism. In both cases, though, it is possible to rehabilitate arguments for Fanaticism based on restricted versions of those principles. The situation is unstable: plausible general principles tell *against* Fanaticism, but restrictions of those same principles (with strengthened auxiliary assumptions) *support* Fanaticism. All of the consistent views that emerge are very strange. (shrink)

Eliminativists sometimes invoke evolutionary debunking arguments against ordinary object beliefs, either to help them establish object skepticism or to soften the appeal of commonsense ontology. I argue that object debunkers face a self-defeat problem: their conclusion undermines the scientific support for one of their premises, because evolutionary biology depends on our object beliefs. Using work on reductionism and multiple realizability from the philosophy of science, I argue that it will not suffice for an eliminativist debunker to simply appeal to some (...) object-free surrogate theory of evolution that results from converting any scientific proposition about some object K into a proposition about simples arranged K-wise. In the process, I examine some hazards peculiar to eliminative reductions of scientific theories, and propose a trilemma for eliminativists who attempt to recoup generality for ontologically sparse reducing theories by appealing to pluralities of simples arranged K-wise. The paper is intended to define and develop the object debunker’s self-defeat problem for further study, and to clarify some of the ways sparse and abundant ontologies interact with scientific theory. (shrink)

Lewis sender‐receiver games illustrate how a meaningful term language might evolve from initially meaningless random signals (Lewis 1969; Skyrms 2006). Here we consider how a meaningful language with a primitive grammar might evolve in a somewhat more subtle sort of game. The evolution of such a language involves the co‐evolution of partitions of the physical world into what may seem, at least from the perspective of someone using the language, to correspond to canonical natural kinds. While the evolved language may (...) allow for the sort of precise representation that is required for successful coordinated action and prediction, the apparent natural kinds reflected in its structure may be purely conventional. This has both positive and negative implications for the limits of naturalized metaphysics. (shrink)

Everett's relative-state formulation of quantum mechanics is an attempt to solve the measurement problem by dropping the collapse dynamics from the standard von Neumann-Dirac theory of quantum mechanics. The main problem with Everett's theory is that it is not at all clear how it is supposed to work. In particular, while it is clear that he wanted to explain why we get determinate measurement results in the context of his theory, it is unclear how he intended to do this. There (...) have been many attempts to reconstruct Everett's no-collapse theory in order to account for the apparent determinateness of measurement outcomes. These attempts have led to such formulations of quantum mechanics as the many-worlds, many-minds, many-histories, and relative-fact theories. Each of these captures part of what Everett claimed for his theory, but each also encounters problems. (shrink)

The Epistemic Objection says that certain theories of time imply that it is impossible to know which time is absolutely present. Standard presentations of the Epistemic Objection are elliptical—and some of the most natural premises one might fill in to complete the argument end up leading to radical skepticism. But there is a way of filling in the details which avoids this problem, using epistemic safety. The new version has two interesting upshots. First, while Ross Cameron alleges that the Epistemic (...) Objection applies to presentism as much as to theories like the growing block, the safety version does not overgeneralize this way. Second, the Epistemic Objection does generalize in a different, overlooked way. The safety objection is a serious problem for a widely held combination of views: “propositional temporalism” together with “metaphysical eternalism”. (shrink)

Epistemic Consequentialism Consequentialism is the view that, in some sense, rightness is to be understood in terms conducive to goodness. Much of the philosophical discussion concerning consequentialism has focused on moral rightness or obligation or normativity. But there is plausibly also epistemic rightness, epistemic obligation, and epistemic normativity. Epistemic rightness is often denoted with talk … Continue reading Consequentialism Epistemic →.

The present chapter describes a probabilistic framework of human reasoning. It is based on probability logic. While there are several approaches to probability logic, we adopt the coherence based approach.

A common line of thought in contemporary metaethics is that certain facts about the evolutionary history of humans make moral realism implausible. Two of the most developed evolutionary cases against realism are found in the works of Richard Joyce and Sharon Street. In what follows, I argue that a form of moral realism that I call proper-function moral realism can meet Joyce and Street's challenges. I begin by sketching the basics of proper-function moral realism. I then present what I take (...) to be the essence of Street's and Joyce's objections, and I show how proper-function realism answers them. (shrink)

“There are no gaps in logical space,” David Lewis writes, giving voice to sentiment shared by many philosophers. But different natural ways of trying to make this sentiment precise turn out to conflict with one another. One is a *pattern* idea: “Any pattern of instantiation is metaphysically possible.” Another is a *cut and paste* idea: “For any objects in any worlds, there exists a world that contains any number of duplicates of all of those objects.” We use resources from model (...) theory to show the inconsistency of certain packages of combinatorial principles and the consistency of others. (shrink)

An important field of probability logic is the investigation of inference rules that propagate point probabilities or, more generally, interval probabilities from premises to conclusions. Conditional probability logic (CPL) interprets the common sense expressions of the form “if . . . , then . . . ” by conditional probabilities and not by the probability of the material implication. An inference rule is probabilistically informative if the coherent probability interval of its conclusion is not necessarily equal to the unit interval (...) [0, 1]. Not all logically valid inference rules are probabilistically informative and vice versa. The relationship between logically valid and probabilistically informative inference rules is discussed and illustrated by examples such as the modus ponens or the affirming the consequent. We propose a method to evaluate the strength of CPL inference. (shrink)

Probabilistic models have started to replace classical logic as the standard reference paradigm in human deductive reasoning. Mental probability logic emphasizes general principles where human reasoning deviates from classical logic, but agrees with a probabilistic approach (like nonmonotonicity or the conditional event interpretation of conditionals). -/- This contribution consists of two parts. In the first part we discuss general features of reasoning systems including consequence relations, how uncertainty may enter argument forms, probability intervals, and probabilistic informativeness. These concepts are of (...) central importance for the psychological task analysis. In the second part we report new experimental data on the paradoxes of the material conditional, the probabilistic modus ponens, the complement task, and data on the probabilistic truth table task. The results of the experiments provide evidence for the hypothesis that people represent indicative conditionals by conditional probability assertions. (shrink)

We prove a representation theorem for preference relations over countably infinite lotteries that satisfy a generalized form of the Independence axiom, without assuming Continuity. The representing space consists of lexicographically ordered transfinite sequences of bounded real numbers. This result is generalized to preference orders on abstract superconvex spaces.

We consider two ways one might use algorithmic randomness to characterize a probabilistic law. The first is a generative chance* law. Such laws involve a nonstandard notion of chance. The second is a probabilistic* constraining law. Such laws impose relative frequency and randomness constraints that every physically possible world must satisfy. While each notion has virtues, we argue that the latter has advantages over the former. It supports a unified governing account of non-Humean laws and provides independently motivated solutions to (...) issues in the Humean best-system account. On both notions, we have a much tighter connection between probabilistic laws and their corresponding sets of possible worlds. Certain histories permitted by traditional probabilistic laws are ruled out as physically impossible. As a result, such laws avoid one variety of empirical underdetermination, but the approach reveals other varieties of underdetermination that are typically overlooked. (shrink)

Could space consist entirely of extended regions, without any regions shaped like points, lines, or surfaces? Peter Forrest and Frank Arntzenius have independently raised a paradox of size for space like this, drawing on a construction of Cantor’s. I present a new version of this argument and explore possible lines of response.

The counterpart theorist has a problem: there is no obvious way to understand talk about actuality in terms of counterparts. Fara and Williamson have charged that this obstacle cannot be overcome. Here I defend the counterpart theorist by offering systematic interpretations of a quantified modal language that includes an actuality operator. Centrally, I disentangle the counterpart relation from a related notion, a ‘representation relation’. The relation of possible things to the actual things they represent is variable, and an adequate account (...) of modal language must keep track of the way it is systematically shifted by modal operators. I apply my account to resolve several puzzles about counterparts and actuality. In technical appendices, I prove some important logical results about this ‘representational’ counterpart system and its relationship to other modal systems. (shrink)

The existence of mereological sums can be derived from an abstraction principle in a way analogous to numbers. I draw lessons for the thesis that “composition is innocent” from neo-Fregeanism in the philosophy of mathematics.

We propose probability logic as an appropriate standard of reference for evaluating human inferences. Probability logical accounts of nonmonotonic reasoning with system p, and conditional syllogisms (modus ponens, etc.) are explored. Furthermore, we present categorical syllogisms with intermediate quantifiers, like the “most . . . ” quantifier. While most of the paper is theoretical and intended to stimulate psychological studies, we summarize our empirical studies on human nonmonotonic reasoning.

Recently in this journal, Jessica Morley and colleagues (AI & SOC 2023 38:411–423) review AI ethics and education, suggesting that a cultural shift is necessary in order to prepare students for their responsibilities in developing technology infrastructure that should shape ways of life for many generations. Current AI ethics guidelines are abstract and difficult to implement as practical moral concerns proliferate. They call for improvements in ethics course design, focusing on real-world cases and perspective-taking tools to immerse students in challenging (...) situations with relatable personal, social and environmental implications. The present paper considers the ACTWith model of moral cognition for use in such training contexts. Morley and colleagues' paper and contemporary literature are reviewed. Whistleblowing as a source for relatable case studies is discussed, and the purpose of ethics education considered. The ACTWith model is introduced, and correlations with contemporaries noted. The ACTWith model has been successfully employed in a broad range of technology ethics courses in the Netherlands and South Korea. Illustrations are offered. Correlations with contemporary efforts are drawn in the context of software engineering. Summary discussion considers strengths and limitations of the ACTWith program. Overall, the paper emphasizes training high-level moral reasoning through guided inquiry education informing lifetime professional practice, and indicates an outstanding need for teachers able to do the job. (shrink)

There is one critical way we honor great tragedies: by never forgetting. Collective remembrance is as old as human society itself, serving as an important source of social cohesion, yet as Jeffrey Andrew Barash shows in this book, it has served novel roles in a modern era otherwise characterized by discontinuity and dislocation. Drawing on recent theoretical explorations of collective memory, he elaborates an important new philosophical basis for it, one that unveils profound limitations to its scope in relation (...) to the historical past. Crucial to Barash’s analysis is a look at the radical transformations that symbolic configurations of collective memory have undergone with the rise of new technologies of mass communication. He provocatively demonstrates how such technologies’ capacity to simulate direct experience—especially via the image—actually makes more palpable collective memory’s limitations and the opacity of the historical past, which always lies beyond the reach of living memory. Thwarting skepticism, however, he eventually looks to literature—specifically writers such as Walter Scott, Marcel Proust, and W. G. Sebald—to uncover subtle nuances of temporality that might offer inconspicuous emblems of a past historical reality. (shrink)

This chapter suggests how certain problematic claims of pantheism might be made more intelligible. It shows, first, that some pantheistic God-talk is comparable to talk involving mass terms; treating “God” as a mass term affords us a way of understanding, for example, how parts can seemingly be identified with the wholes of which they are the parts, as per the claim that “God is everything and everything is God”. This chapter then goes on to describe a contemporary variant of panpsychism, (...) a variant speculatively predicated on the affinity between intentional states and causal dispositions. This allows for a conception of the world as God’s brain, cashed out in terms of a “panintentionalism” that admits of various organizational possibilities for causal dispositional states, comparable to the organization of intentional states in human brains. (shrink)

“Pragmatic encroachers” about knowledge generally advocate two ideas: (1) you can rationally act on what you know; (2) knowledge is harder to achieve when more is at stake. Charity Anderson and John Hawthorne have recently argued that these two ideas may not fit together so well. I extend their argument by working out what “high stakes” would have to mean for the two ideas to line up, using decision theory.

Prior work proposes a view of development of purpose and source of meaning in life as a more or less temporally distal project ideal self-situation in terms of which intermediate situations are experienced and prospects evaluated. This work considers Augustine on ensoulment alongside current work into self as adapted routines to common social regularities of the sort that Augustine found deficient. How can we account for such diversity of self-reported value orientation in terms of common structural dynamics differently developed, embodied (...) and enacted over the life course? This work in progress represents divergent views as different sorts of error theory, and hypothesizes that differential development of spindle neural projections underlies different accounts of error for attentive self-correction through iterative attenuation. Some implications for AI augmentation and value alignment of autonomous agents developed on such a model are briefly entertained. (shrink)

Some philosophers respond to Leibniz’s “shift” argument against absolute space by appealing to antihaecceitism about possible worlds, using David Lewis’s counterpart theory. But separated from Lewis’s distinctive system, it is difficult to understand what this doctrine amounts to or how it bears on the Leibnizian argument. In fact, the best way of making sense of the relevant kind of antihaecceitism concedes the main point of the Leibnizian argument, pressing us to consider alternative spatiotemporal metaphysics.

Various semantics for studying the square of opposition and the hexagon of opposition have been proposed recently. We interpret sentences by imprecise (set-valued) probability assessments on a finite sequence of conditional events. We introduce the acceptability of a sentence within coherence-based probability theory. We analyze the relations of the square and of the hexagon in terms of acceptability. Then, we show how to construct probabilistic versions of the square and of the hexagon of opposition by forming suitable tripartitions of the (...) set of all coherent assessments. Finally, as an application, we present new versions of the square and of the hexagon involving generalized quantifiers. (shrink)

Levinas and the Philosophy of Religion Jeffrey L. Kosky Reveals the interplay of phenomenology and religion in Levinas’s thought. "Kosky examines Levinas’s thought from the perspective of the philosophy of religion and he does so in a way that is attentive to the philosophical nuances of Levinas’s argument.... an insightful, well written, and carefully documented study... that uniquely illuminates Levinas’s work." —John D. Caputo For readers who suspect there is no place for religion and morality in postmodern philosophy, (...) class='Hi'>Jeffrey L. Kosky suggests otherwise in this skillful interpretation of the ethical and religious dimensions of Emmanuel Levinas’s thought. Placing Levinas in relation to Hegel and Nietzsche, Husserl and Heidegger, Derrida and Marion, Kosky develops religious themes found in Levinas’s work and offers a way to think and speak about ethics and morality within the horizons of contemporary philosophy of religion. Kosky embraces the entire scope of Levinas’s writings, from Totality and Infinity to Otherwise than Being, contrasting Levinas’s early religious and moral thought with that of his later works while exploring the nature of phenomenological reduction, the relation of religion and philosophy, the question of whether Levinas can be considered a Jewish thinker, and the religious and theological import of Levinas’s phenomenology. Kosky stresses that Levinas is first and foremost a phenomenologist and that the relationship between religion and philosophy in his ethics should cast doubt on the assumption that a natural or inevitable link exists between deconstruction and atheism. Jeffrey L. Kosky is translator of On Descartes’ Metaphysical Prism: The Constitution and the Limits of Onto-theo-logy in Cartesian Thought by Jean-Luc Marion. He has taught at Williams College. Indiana Series in the Philosophy of Religion—Merold Westphal, general editor May 2001 272 pages, 6 1/8 x 9 1/4, bibl., index, append. cloth 0-253-33925-1 $39.95 s / £30.50. (shrink)

Tonkens has issued a seemingly impossible challenge, to articulate a comprehensive ethical framework within which artificial moral agents satisfy a Kantian inspired recipe—"rational" and "free"—while also satisfying perceived prerogatives of machine ethicists to facilitate the creation of AMAs that are perfectly and not merely reliably ethical. Challenges for machine ethicists have also been presented by Anthony Beavers and Wendell Wallach. Beavers pushes for the reinvention of traditional ethics to avoid "ethical nihilism" due to the reduction of morality to mechanical causation. (...) Wallach pushes for redoubled efforts toward a comprehensive account of ethics to guide machine ethicists on the issue of artificial moral agency. Options, thus, present themselves: reinterpret traditional ethics in a way that affords a comprehensive account of moral agency inclusive of both artificial and natural agents, or give up on the possibility and “muddle through” regardless. This series of papers pursues the first option, meets Tonkens' "challenge" and pursues Wallach's ends through Beavers’ proposed means, by "landscaping" traditional moral theory in resolution of a comprehensive account of moral agency. This first paper sets out the challenge and establishes the tradition that Kant had inherited from Aristotle, briefly entertains an Aristotelian AMA, fields objections, and ends with unanswered questions. The next paper in this series responds to the challenge in Kantian terms, and argues that a Kantian AMA is not only a possibility for Machine ethics research, but a necessary one. (shrink)

I examine what the mathematical theory of random structures can teach us about the probability of Plenitude, a thesis closely related to David Lewis's modal realism. Given some natural assumptions, Plenitude is reasonably probable a priori, but in principle it can be (and plausibly it has been) empirically disconfirmed—not by any general qualitative evidence, but rather by our de re evidence.

This paper explores the idea that it is instrumentally valuable to learn normative truths. We consider an argument for "normative hedging" based on this principle, and examine the structure of decision-making under moral uncertainty that arises from it. But it also turns out that the value of normative information is inconsistent with the principle that learning *empirical* truths is instrumentally valuable. We conclude with a brief comment on "metanormative regress.".

Everyday life reasoning and argumentation is defeasible and uncertain. I present a probability logic framework to rationally reconstruct everyday life reasoning and argumentation. Coherence in the sense of de Finetti is used as the basic rationality norm. I discuss two basic classes of approaches to construct measures of argument strength. The first class imposes a probabilistic relation between the premises and the conclusion. The second class imposes a deductive relation. I argue for the second class, as the first class is (...) problematic if the arguments involve conditionals. I present a measure of argument strength that allows for dealing explicitly with uncertain conditionals in the premise set. (shrink)

The modus ponens (A -> B, A :. B) is, along with modus tollens and the two logically not valid counterparts denying the antecedent (A -> B, ¬A :. ¬B) and affirming the consequent, the argument form that was most often investigated in the psychology of human reasoning. The present contribution reports the results of three experiments on the probabilistic versions of modus ponens and denying the antecedent. In probability logic these arguments lead to conclusions with imprecise probabilities. In the (...) modus ponens tasks the participants inferred probabilities that agreed much better with the coherent normative values than in the denying the antecedent tasks, a result that mirrors results found with the classical argument versions. For modus ponens a surprisingly high number of lower and upper probabilities agreed perfectly with the conjugacy property (upper probabilities equal one complements of the lower probabilities). When the probabilities of the premises are imprecise the participants do not ignore irrelevant (“silent”) boundary probabilities. The results show that human mental probability logic is close to predictions derived from probability logic for the most elementary argument form, but has considerable difficulties with the more complex forms involving negations. (shrink)

3 Abstract This paper is about modeling morality, with a proposal as to the best 4 way to do it. There is the small problem, however, in continuing disagreements 5 over what morality actually is, and so what is worth modeling. This paper resolves 6 this problem around an understanding of the purpose of a moral model, and from 7 this purpose approaches the best way to model morality.

Traditionally, syllogisms are arguments with two premises and one conclusion which are constructed by propositions of the form “All… are…” and “At least one… is…” and their respective negated versions. Unfortunately, the practical use of traditional syllogisms is quite restricted. On the one hand, the “All…” propositions are too strict, since a single counterexample suffices for falsification. On the other hand, the “At least one …” propositions are too weak, since a single example suffices for verification. The present contribution studies (...) algebraic interpretations of syllogisms with comparative quantifiers (e.g., “Most… are…”) and quantitative quantifiers (e.g., “n/m… are…”, “all, except n… are…”). This modern version of syllogistics is intended to be a more adequate framework for argumentation theory than traditional syllogistics. (shrink)

Achieving a high quality of life is dependent upon how individuals face adversity. Positive psychological interventions are well-suited to support coping efforts; however, experimental research is limited. The purpose of the current research was to examine whether different savoring interventions could increase important coping resources in response to a social-evaluative hassle. We completed an experimental mixed subject design study with a university student sample. All participants completed a hassle induction task and were then randomly assigned into different intervention groups. Positive (...) emotion ratings were collected at three points in time. Results revealed a significant time x intervention interaction effect, such that individuals in the savoring the moment intervention reported higher levels of positive emotions compared to individuals assigned to the true control group, guided imagery control group, and savoring through reminiscence intervention. Such findings represent a significant extension to savoring theory and offer support for savoring the moment exercises as a primary prevention strategy to bolster effective responses to social-evaluative hassles. (shrink)

Teaching critical thinking skill is a central pedagogical aim in many courses. These skills, it is hoped, will be both portable and durable. Yet, both of these virtues are challenged by pervasive and potent cognitive biases, such as motivated reasoning, false consensus bias and hindsight bias. In this paper, I argue that a focus on the development of metacognitive skill shows promise as a means to inculcate debiasing habits in students. Such habits will help students become more critical reasoners. I (...) close with suggestions for implementing this strategy. (shrink)

This paper offers a non-traditional account of what was really at stake in debates over the legitimacy of teleology and teleological explanations in the later medieval and early modern periods. It is divided into four main sections. The first section highlights two defining features of ancient and early medieval views on teleology, namely, that teleological explanations are on a par (or better) with efficient causal explanations, and that the objective goodness of outcomes may explain their coming about. The second section (...) argues that it was the first thesis – the thesis of explanatory parity –that came under attack by mainstream philosophers in the later medieval and early modern traditions, rather than teleology per se. The third section argues similarly that it was the second thesis – the thesis of explanatory goodness – that was the object of Spinoza’s critique of final causes, rather than teleology itself. Finally, the fourth section argues that Leibniz’s claim to be a champion of traditional teleology rests on his willingness to defend both the theses of explanatory parity and goodness against the very charges that led to their demise. The essay concludes by contrasting the narrative offered here with Don Garrett’s recent account according to which “it is not Leibniz but Spinoza who holds the position on teleology and teleological explanation nearest to that of Aristotle” (312). (shrink)

Nick Bostrom’s recently patched ‘‘simulation argument’’ (Bostrom in Philos Q 53:243–255, 2003; Bos- trom and Kulczycki in Analysis 71:54–61, 2011) purports to demonstrate the probability that we ‘‘live’’ now in an ‘‘ancestor simulation’’—that is as a simulation of a period prior to that in which a civilization more advanced than our own—‘‘post-human’’—becomes able to simulate such a state of affairs as ours. As such simulations under consid- eration resemble ‘‘brains in vats’’ (BIVs) and may appear open to similar objections, the (...) paper begins by reviewing objections to BIV-type proposals, specifically those due a presumed mad envatter. In counter example, we explore the motivating rationale behind current work in the development of psychologically realistic social simula- tions. Further concerns about rendering human cognition in a computational medium are confronted through review of current dynamic systems models of cognitive agency. In these models, aspects of the human condition are repro- duced that may in other forms be considered incomputable, i.e., political voice, predictive planning, and consciousness. The paper then argues that simulations afford a unique potential to secure a post-human future, and may be nec- essary for a pre-post-human civilization like our own to achieve and to maintain a post-human situation. Long-s- tanding philosophical interest in tools of this nature for Aristotle’s ‘‘statesman’’ and more recently for E.O. Wilson in the 1990s is observed. Self-extinction-level threats from State and individual levels of organization are compared, and a likely dependence on large-scale psychologically realistic simulations to get past self-extinction-level threats is projected. In the end, Bostrom’s basic argument for the conviction that we exist now in a simulation is reaffirmed. (shrink)

This chapter presents probability logic as a rationality framework for human reasoning under uncertainty. Selected formal-normative aspects of probability logic are discussed in the light of experimental evidence. Specifically, probability logic is characterized as a generalization of bivalent truth-functional propositional logic (short “logic”), as being connexive, and as being nonmonotonic. The chapter discusses selected argument forms and associated uncertainty propagation rules. Throughout the chapter, the descriptive validity of probability logic is compared to logic, which was used as the gold standard (...) of reference for assessing the rationality of human reasoning in the 20th century. (shrink)

This is the commentary on Richard C. Richards, "Humor and Happiness”, read at the Lighthearted Philosophers' Society 5th Annual Conference, 14 October 2011, Treasure Island, Florida.

Nonmonotonic logics allow—contrary to classical (monotone) logics— for withdrawing conclusions in the light of new evidence. Nonmonotonic reasoning is often claimed to mimic human common sense reasoning. Only a few studies, though, have investigated this claim empirically. system p is a central, broadly accepted nonmonotonic reasoning system that proposes basic rationality postulates. We previously investigated empirically a probabilistic interpretation of three selected rules of system p. We found a relatively good agreement of human reasoning and principles of nonmonotonic reasoning according (...) to the coherence interpretation of system p. This study reports an experiment on the cautious monotonicity Rule and its “incautious” counterpart that is not contained in system p, namely the monotonicity Rule. In accordance with our previous results, the data suggest that people reason nonmonotonically: the subjects in the cautious monotonicity condition infer significantly tighter intervals close to the coherence interpretation of system p compared with the subjects in the incautious monotonicity condition where rather wide (and hence non-informative) intervals are inferred. (shrink)

We present probabilistic approaches to check the validity of selected connexive principles within the setting of coherence. Connexive logics emerged from the intuition that conditionals of the form If ∼A, then A, should not hold, since the conditional’s antecedent ∼A contradicts its consequent A. Our approach covers this intuition by observing that for an event A the only coherent probability assessment on the conditional event A|~A is p(A|~A)=0 . Moreover, connexive logics aim to capture the intuition that conditionals should express (...) some “connection” between the antecedent and the consequent or, in terms of inferences, validity should require some connection between the premise set and the conclusion. This intuition is covered by a number of principles, a selection of which we analyze in our contribution. We present two approaches to connexivity within coherence-based probability logic. Specifically, we analyze connections between antecedents and consequents firstly, in terms of probabilistic constraints on conditional events (in the sense of defaults, or negated defaults) and secondly, in terms of constraints on compounds of conditionals and iterated conditionals. After developing different notions of negations and notions of validity, we analyze the following connexive principles within both approaches: Aristotle’s Theses, Aristotle’s Second Thesis, Abelard’s First Principle and selected versions of Boethius’ Theses. We conclude by remarking that coherence-based probability logic offers a rich language to investigate the validity of various connexive principles. (shrink)