In this paper we explore the thesis that the role of argumentation in practical reasoning in general and legal reasoning in particular is to justify the use of defeasible rules to derive a conclusion in preference to the use of other defeasible rules to derive a conflicting conclusion. The defeasibility of rules is expressed by means of non-provability claims as additional conditions of the rules.We outline an abstract approach to defeasible reasoning and argumentation which includes many existing formalisms, including default (...) logic, extended logic programming, non-monotonic modal logic and auto-epistemic logic, as special cases. We show, in particular, that the admissibility semantics for all these formalisms has a natural argumentation-theoretic interpretation and proof procedure, which seem to correspond well with informal argumentation. (shrink)
Human intentional communication is marked by its flexibility and context sensitivity. Hypothesized brain mechanisms can provide convincing and complete explanations of the human capacity for intentional communication only insofar as they can match the computational power required for displaying that capacity. It is thus of importance for cognitive neuroscience to know how computationally complex intentional communication actually is. Though the subject of considerable debate, the computational complexity of communication remains so far unknown. In this paper we defend the position that (...) the computational complexity of communication is not a constant, as some views of communication seem to hold, but rather a function of situational factors. We present a methodology for studying and characterizing the computational complexity of communication under different situational constraints. We illustrate our methodology for a model of the problems solved by receivers and senders during a communicative exchange. This approach opens the way to a principled identification of putative model parameters that control cognitive processes supporting intentional communication. (shrink)
People are prone to ascribe value to persons they love. However, the relation between love and value is far from straightforward. This is particularly evident given certain views on the nature of love. Setting out from the idea that what causes us to have an attitude towards an object need not be found in the intentional content of the attitude, this paper depicts love as an attitude that takes non-fungible persons as intentional objects. Taking this view (...) as a starting point, the paper shows why it is difficult to combine with certain views on value. The main challenge comes from the idea that value judgments are universalizable. This view squares badly with the thought that the people whom we love are irreplaceable. Introducing the idea that properties may have different functions in the intentional content of the attitude, this paper determines what precisely it is about love that makes it hard to combine with universalizability. Moreover, it suggests two ways of meeting this challenge. (shrink)
Humans have a remarkable capacity for tuning their communicative behaviors to different addressees, a phenomenon also known as recipient design. It remains unclear how this tuning of communicative behavior is implemented during live human interactions. Classical theories of communication postulate that recipient design involves perspective taking, i.e., the communicator selects her behavior based on her hypotheses about beliefs and knowledge of the recipient. More recently, researchers have argued that perspective taking is computationally too costly to be a plausible mechanism in (...) everyday human communication. These researchers propose that computationally simple mechanisms, or heuristics, are exploited to perform recipient design. Such heuristics may be able to adapt communicative behavior to an addressee with no consideration for the addressee's beliefs and knowledge. To test whether the simpler of the two mechanisms is sufficient for explaining the `how' of recipient design we studied communicators' behaviors in the context of a non-verbal communicative task (the Tacit Communication Game, TCG). We found that the specificity of the observed trial-by-trial adjustments made by communicators is parsimoniously explained by perspective taking, but not by simple heuristics. This finding is important as it suggests that humans do have a computationally efficient way of taking beliefs and knowledge of a recipient into account. (shrink)
There is a vast amount of potential mappings between behaviours and intentions in communication: a behaviour can indicate a multitude of different intentions, and the same intention can be communicated with a variety of behaviours. Humans routinely solve these many-to-many referential problems when producing utterances for an Addressee. This ability might rely on social cognitive skills, for instance, the ability to manipulate unobservable summary variables to disambiguate ambiguous behaviour of other agents (“mentalizing”) and the drive to invest resources into changing (...) and understanding the mental state of other agents (“communicative motivation”). Alternatively, the ambiguities of verbal communicative interactions might be solved by general-purpose cognitive abilities that process cues that are incidentally associated with the communicative interaction. In this study, we assess these possibilities by testing which cognitive traits account for communicative success during a verbal referential task. Cognitive traits were assessed with psychometric scores quantifying motivation, mentalizing abilities, and general-purpose cognitive abilities, taxing abstract visuo-spatial abilities. Communicative abilities of participants were assessed by using an on-line interactive task that required a speaker to verbally convey a concept to an Addressee. The communicative success of the utterances was quantified by measuring how frequently a number of Evaluators would infer the correct concept. Speakers with high motivational and general-purpose cognitive abilities generated utterances that were more easily interpreted. These findings extend to the domain of verbal communication the notion that motivational and cognitive factors influence the human ability to rapidly converge on shared communicative innovations. (shrink)
Several studies have revealed that posterior parietal and frontal regions support planning of hand movements but far less is known about how these cortical regions interact during the mental simulation of a movement. Here, we have used magnetoencephalography (MEG) to investigate oscillatory interactions between posterior and frontal areas during the performance of a well-established motor imagery task that evokes motor simulation: mental rotation of hands. Motor imagery induced sustained power suppression in the alpha and beta band over the precentral gyrus (...) and a power increase in the gamma band over bilateral occipito-parietal cortex. During motor imagery of left hand movements, there was stronger alpha and beta band suppression over the right precentral gyrus. The duration of these power changes increased, on a trial-by-trial basis, as a function of the motoric complexity of the imagined actions. Crucially, during a specific period of the movement simulation, the power fluctuations of the frontal beta-band oscillations became coupled with the occipito-parietal gamma-band oscillations. Our results provide novel information about the oscillatory brain activity of posterior and frontal regions. The persistent functional coupling between these regions during task performance emphasizes the importance of sustained interactions between frontal and occipito-parietal areas during mental simulation of action. (shrink)
The default mode network (DMN) of the brain consists of areas that are typically more active during rest than during active task performance. Recently however, this network has been shown to be activated by certain types of tasks. Social cognition, particularly higher-order tasks such as attributing mental states to others, has been suggested to activate a network of areas at least partly overlapping with the DMN. Here, we explore this claim, drawing on evidence from meta-analyses of functional MRI data and (...) studies investigating the structural and functional connectivity of the social brain. Finally, we discuss recent evidence for the existence of a DMN in non-human primates and evidence for its involvement in mediating social abilities. We end by discussing some of the implications of these observations. (shrink)
When established communication systems cannot be used, people rapidly create novel systems to modify the mental state of another agent according to their intentions. However, there are dramatic inter-individual differences in the implementation of this human competence for communicative innovation. Here we characterize psychological sources of inter-individual variability in the ability to build a shared communication system from scratch. We consider two potential sources of variability in communicative skills. Cognitive traits of two individuals could independently influence their joint ability to (...) establish a communication system. Another possibility is that the overlap between those individual traits influences the communicative performance of a dyad. We assess these possibilities by quantifying the relationship between cognitive traits and behavior of communicating dyads. Cognitive traits were assessed with psychometric scores quantifying cooperative attitudes and fluid intelligence. Competence for implementing successful communicative innovations was assessed by using a non-verbal communicative task. Individual capacities influence communicative success when communicative innovations are generated. Dyadic similarities and individual traits modulate the type of communicative strategy chosen. The ability to establish novel communicative actions was influenced by a combination of the communicator’s ability to understand intentions and the addressee’s ability to recognize patterns. Communicative pairs with comparable systemizing abilities or behavioral inhibition were more likely to explore the search space of possible communicative strategies by systematically adding new communicative behaviors to those already available. No individual psychometric measure seemed predominantly responsible for communicative success. These findings support the notion that the human ability for fast communicative innovations represents a special type of complex collaborative activity. (shrink)
If motor imagery uses neural structures involved in action execution, then the neural correlates of imagining an action should differ between individuals who tend to execute the action differently. Here we report fMRI data showing that motor imagery is influenced by the way people habitually perform motor actions with their particular bodies; that is, motor imagery is ‘body-specific’ (Casasanto, 2009). During mental imagery for complex hand actions, activation of cortical areas involved in motor planning and execution was left-lateralized in right-handers (...) but right-lateralized in left-handers. We conclude that motor imagery involves the generation of an action plan that is grounded in the participant’s motor habits, not just an abstract representation at the level of the action’s goal. People with different patterns of motor experience form correspondingly different neurocognitive representations of imagined actions. (shrink)
This paper elucidates the structure of Toni Morrison’s novel, Beloved, using the framework of human emotions in response to grieving and death as developed by Elisabeth Kubler-Ross. Through her studies of terminally ill patients, Kubler-Ross identified five stages when approaching death: denial and isolation, anger, bargaining, depression and acceptance. These stages accurately fill the process that the character Sethe experiences in the novel as she learns to accept her daughter’s death.
In discussing Drucilla Cornell's remarks about Toni Morrison's Beloved, I consider epistemological questions raised by the acquiring of understanding of racism, particularly the deep-rooted racism embodied in social norms and values. I suggest that questions about understanding racism are, in part, questions about personal and political identities and that questions about personal and political identities are often, importantly, epistemological questions.
Whoever enters a food store in Switzerland, nowadays, most probably passes by a conspicuous crate for depositing empty glass containers for Toni yogurts. But who actually would know that the story behind the recyclable glass containers is one of the most interesting and informative cases, where one company successfully integrated ecological considerations of society-at-large into their company's marketing strategy, making it eventually a great business success. It is an encouraging story for those who are trying to find ways to (...) include a sense of social responsibility into company policies without calling for more state intervention to bring it about. It is a sobering story at the same time, leaving little doubt, that there are no easy and undisputed solutions for complex and ambiguous problems. (shrink)
This article provides a Foucauldian analysis of whiteness as a philosophical, political, anthropological and epistemological regime, undergirded by a power/knowledge nexus, which shapes what it meansto embody whiteness vis-a-vis the Black body/self. As a specific historically constructed standpoint, one that takes itselfas a “universal” value, and through a genealogical reading, whiteness is revealed as akind of emergence (Entstehung), a reactive value-creating power which shapes how the Black body/self is disciplined and how the Black body/selfcomes to introject a self-denigrating episteme. This (...) introjected episteme is explored as being fueled by white ressentiment. Coming under normalizing disciplinary techniques of whiteness, which is historically demonstrated, it is argued that Blacks carne to intemalize a form of self-ressentiment. Through the existentially rich narrative text of Toni Morrison’s The Bluest Eye, the author shows that Pecola Breedlove, though a fictional character, is the racially distorted (and racially self-hating) product of certain contingent interpersonal and historical practices that once genealogically revealed create the possibility of radically dismantling their impact. (shrink)
Toni Morrison is widely recognized as an American’s prominent novelist, who magnificently explores the life of the black, especially that of black women. Her Nobel Prize Lecture, in which she again tells a story of a black woman, can be regarded as an epitome of Morrison’s thoughts. The dialogue between the blind black old woman and the young people is full of wisdom and profoundness.
L'essor de la perspective linéaire a suscité de nombreuses polémiques tout au long du Quattrocento et du Cinquecento, opposant les partisans d'une géométrisation artificialiste de la vision à ceux qui vantaient les qualités du dessin d'après nature ou invoquaient des arguments de nature physiologique. Ces débats peuvent être retracés à partir des quatre alternatives qui en constituent le noyau dur : champ de vision restreint vs. large ; immobilité vs. mobilité oculaire ; tableau plan vs. curviligne ; vision monoculaire vs. (...) binoculaire. En retenant les premiers termes de ces quatre alternatives, l'histoire de la perspective a rejeté de nombreux systèmes hétérodoxes. Du point de vue de la mathématisation, l'intérêt de ces débats tient à ce qu'ils ont succédé, et non précédé, l'adoption du dispositif perspectif comme intersection de la pyramide visuelle. L'histoire de la perspective linéaire offre ainsi un authentique cas de justification a posteriori des fondements ou, pour ainsi dire, de mathématisation à rebours. (shrink)
In the article ‘After-birth abortion: why should the baby live?’ arguments are made in favour of the moral permissibility of intentionally killing newborn infants, under particular conditions. Here we argue that their arguments are based on an indefensible view of personhood, and we question the logic of harm and interest that informs their arguments. Furthermore, we argue that the conclusions here are so contrary to ordinary moral intuitions that the argument and conclusions based upon it—including those which defend more mainstream (...) methods of abortion—should be treated with immediate suspicion. (shrink)