We propose that people typically reason about realistic situations using neither content-free syntactic inference rules nor representations of specific experiences. Rather, people reason using knowledge structures that we term pragmatic reasoning schemas, which are generalized sets of rules defined in relation to classes of goals. Three experiments examined the impact of a “permission schema” on deductive reasoning. Experiment 1 demonstrated that by evoking the permission schema it is possible to facilitate performance in Wason's selection paradigm for subjects who have had (...) no experience with the specific content of the problems. Experiment 2 showed that a selection problem worded in terms of an abstract permission elicited better performance than one worded in terms of a concrete but arbitrary situation, providing evidence for an abstract permission schema that is free of domain-specific content. Experiment 3 provided evidence that evocation of a permission schema affects not only tasks requiring procedural knowledge, but also a linguistic rephrasing task requiring declarative knowledge. In particular, statements in the form if p then q were rephrased into the form p only if q with greater frequency for permission than for arbitrary statements, and rephrasings of permission statements produced a pattern of introduction of modals totally unlike that observed for arbitrary conditional statements. Other pragmatic schemas, such as “causal” and “evidence” schemas can account for both linguistic and reasoning phenomena that alternative hypotheses fail to explain. (shrink)

In this study on deduction, the authors argue that people reason by imagining the relevant state of affairs, ie building an internal model of it, formulating a tentative conclusion based on this model and then searching for alternative models.

What is “the relation of logic to philosophy?” Is “the traditional bond between logic and philosophy severed?” That the field of logic has evolved away from philosophy proper is supported by the apparent fact that most logic research today is carried out by members of university departments other than philosophy with the main logical concern of philosophy departments being elementary logic instruction. So, it appears to many observers that logic used to be a part of philosophy, but that at the (...) leading edge of its research and study it is no longer a basic or pure component of the field of philosophy. Although I myself do not believe this assessment, I will presume for the sake of discussion that it is widely believed. Against this supposed separation of logic from philosophy, I will show how to re-establish the connection. (shrink)

This new edition of the classic Contemporary Theories of Knowledge has been significantly updated to include analyses of the recent literature in epistemology.

Against the traditional view, Alvin Goldman argues that logic, probability theory, and linguistic analysis cannot by themselves delineate principles of rationality or justified belief. The mind's operations must be taken into account.

By a logical theory I mean a formal system together with its semantics, meta-theory, and rules for translating ordinary language into its notation. Logical theories can be used descriptively (for example, to represent particular arguments or to depict the logical form of certain sentences). Here the logician uses the usual methods of empirical science to assess the correctness of his descriptions. However, the most important applications of logical theories are normative, and here, I argue, the epistemology is that of wide (...) reflective equilibrium. The result is that logic not only assesses our inferential practice but also changes it. I tie my discussion to Thagard's views concerning the relationship between psychology and logic, arguing against him that psychology has and should have only a peripheral role in normative (and most descriptive) applications of logic. (shrink)

Change in View offers an entirely original approach to the philosophical study of reasoning by identifying principles of reasoning with principles for revising one's beliefs and intentions and not with principles of logic. This crucial observation leads to a number of important and interesting consequences that impinge on psychology and artificial intelligence as well as on various branches of philosophy, from epistemology to ethics and action theory. Gilbert Harman is Professor of Philosophy at Princeton University. A Bradford Book.

The object of this paper is to show why recent research in the psychology of deductive and probabilistic reasoning does not have.

I want to explore what happens to two philosophical issues when we assume that the mind, a functional device, is to be understood by the same sort of functional analysis that guides biological investigation of other organismic systems and characteristics. The first problem area concerns the concept of rationality, its connection with reliability and reproductive success, and the status of rationality hypotheses in attribution of beliefs. It has been argued that ascribing beliefs to someone requires the assumption that that person (...) is rational. It also has been argued that evolutionary theory can account for the capacity we have for rational thought by appealing to the idea that rational methods for constructing beliefs are reliable and therefore represented a selected advantage. Both of these claims about rationality are critically examined. In the second part of the paper, I turn to some criticisms that have been advanced against "functionalist" solutions to the mind/body problem. These criticisms are defused when that doctrine is understood in terms of a Teleological (rather than a Turing Machine) notion of function. However, functionalism does not emerge totally unscathed. Voltaire's Dr. Pangloss saw everything in terms of its function and its perfect performance of its function. In the philosophy of mind, his influence lives on in the form of two ideas: (i) that we must possess rational methods for constructing beliefs, since our minds are the product of natural selection, and (ii) that psychological states and properties are individuated by their psychological functions. Contemporary biology provides the resources for avoiding Pangloss's wideeyed teleology in the study of adaptation. It is to be hoped that progress in psychology will loosen the grip of Panglossian assumptions in the study of mind. (shrink)

The end of the nineteenth century is remembered as a time when psychology freed itself from philosophy and carved out an autonomous subject matter for itself. In fact, this time of emancipation was also a time of exile: while the psychologists were leaving, philosophers were slamming the door behind them. Frege is celebrated for having demonstrated the irrelevance of psychological considerations to philosophy. Some of Frege’s reasons for distinguishing psychological questions from philosophical ones were sound, but one of Frege’s most (...) influential arguments, which was elaborated upon and advocated by the positivists, vastly overestimated the gap separating the two disciplines. (shrink)

I have been supposing that for the theory of reasoning, explicit belief is an all-or-nothing matter, I have assumed that, as far as principles of reasoning are concerned, one either believes something explicitly or one does not; in other words an appropriate "representation" is either in one's "memory" or not. The principles of reasoning are principles for modifying such all-or-nothing representations. This is not to deny that in some ways belief is a matter of degree. For one thing implicit belief (...) is certainly a matter of degree, since it is a matter of how easily and automatically one can infer something from what one believes explicitly. Furthermore, explicit belief is a matter of degree in the sense that one believes some things more strongly than others. Sometimes one is only somewhat inclined to believe something, sometimes one is not sure what to believe, sometimes one is inclined to disbelieve something, sometimes one is quite confident something is not so, and so forth. (shrink)

This is a book of philosophy, written by a philosopher and intended for anyone who knows enough philosophy to have been seriously injured, antagonised, mystified or intoxicated by it. Stove is passionately polemical, a philosophical counterpart to Tom Wolfe. Setting out to deflate a few philosophical reputations, he lambastes both the dead and the living. Yet he says things that need to be said, and that others often lack the courage to say.

Toward theory a homuncular of believing For years and years, philosophers took thoughts and beliefs to be modifications of incorporeal Cartesian egos. ...

A Border Disputeintegrates the latest work in logic and semantics into a theory of language learning and presents six worked examples of how that theory revolutionizes cognitive psychology. Macnamara's thesis is set against the background of a fresh analysis of the psychologism debate of the 19th-century, which led to the current standoff between logic and psychology. The book presents psychologism through the writings of John Stuart Mill and Immanuel Kant, and its rejection by Gottlob Frege and Edmund Husserl. It then (...) works out the general thesis that logic ideally presents a competence theory for part of human reasoning and explains how logical intuition is grounded in properties of the mind. The next six chapters present examples that illustrate the relevance of logic to psychology. These problems are all in the semantics of child language (the learning of proper names, personal pronouns, sortals or common nouns, quantifiers, and the truth-functional connectives) and reflect Macnamara's rich background in developmental psychology, particularly child language - a field, he points out, that embraces all of cognition. Technical problems raised by but not included in the examples in the main part of the text are dealt with in a separate chapter. The book concludes by describing laws in cognitive psychology, or the type of science made possible by Macnamara's new theory. John Macnamara is Professor of Psychology and Director of the Program in the History and Philosophy of Science, McGill University. A Bradford Book. (shrink)

The aim of this paper is to describe a methodology for revising logical principles in the light of empirical psychological findings. Historical philosophy of science and wide reflective equilibrium in ethics are considered as providing possible models for arguing from the descriptive to the normative. Neither is adequate for the psychology/logic case, and a new model is constructed, employing criteria for evaluating inferential systems. Once we have such criteria, the notion of reflective equilibrium becomes redundant.

Three experiments are reported which show that in certain contexts subjects reject instances of the valid modus ponens and modus tollens inference form in conditional arguments. For example, when a conditional premise, such as: If she meets her friend then she will go to a play, is accompanied by a conditional containing an additional requirement: If she has enough money then she will go to a play, subjects reject the inference from the categorical premise: She meets her friend, to the (...) conclusion: She will go to a play. Other contexts suppress the conditional fallacies. The first experiment demonstrates the effects of context on conditional reasoning. The second experiment shows that the inference suppression disappears when the categorical premise refers to both of the antecedents, such as: She meets her friend and she has enough money. In this case, subjects make both the valid inferences and the fallacies, regardless of the contextual information. The third experiment establishes that when subjects are given general information about the duration of a situation in which a conditional inducement was uttered, such as: If you shout then I will shoot you, they reject both the valid inferences and the fallacies. The results suggest that the interpretation of premises plays an even more central role in reasoning than has previously been admitted. Trois expériences montrent que dans certains contextes les sujets rejettent des instances valides de modus ponens et de modus tollens dans des énoncés conditionnels. Par exemple, quand une prémisse conditionnelle comme: Si elle rencontre son ami, alors elle ira jouer, est accompagnée par une phrase contenant une condition supplémentaire: Si elle a assez d'argent, alors elle ira jouer, les sujets rejettent l'inférence liant la prémisse catégorielle: Elle rencontre son ami, à la conclusion: Elle ira jouer. D'autres contextes éliminent également les inférences conditionnelles fallacieuses. La premiére expérience démontre l'effet du contexte sur la raisonnement conditionnel. La deuxiéme expérience montre que la suppression de l'inférence disparait quand la prémisse catégorielle fait référence aux deux antécédants, comme: Elle rencontre son ami et elle a assez d'argent. Dans ce cas, les sujets font aussi bien les inférences valides et fallacieuses, quelle que soit l'information contextuelle. La troisiéme expérience établit que quand l'on donne aux sujets des informations générales à propos de la durée d'une situation dans laquelle une conditionnelle a été prononcée, comme Si tu cries, alors je te tire dessus, ils rejettent autant les inférences valides que les inférences fallacieuses. Ces résultats suggèrent que l'interprétation des prémisses joue un rŏle encore plus central dans le raisonnement que l'on admettait auparavant. (shrink)

In “Real Logic in Philosophy” I argued that the study of logic be conceived to be the study of the human faculty for correct reasoning. I relabeled the field of study, as well as the object studied, “real logic”- thereby introducing an ambiguity akin to that found with ‘grammar’. ‘Grammar’ is a term for both a field of study and for the object studied. The parallel to grammar and ‘grammar’ was not accidental. I proposed that the faculty for correct reasoning (...) is analogous to the faculty for natural language understanding. So, just as one’s knowlege of a NL can be usefully thought of as an “internalized” grammar, so one’s faculty for Reasoning Logically—or for “real logic” —can be thought of as an “internalized” system. The faculty for correct inference is, then, an internalized real logic. (shrink)