周延理论和内插定理

三段论规则中的周延律一般是指中项在前提中至少周延一次,前提中不周延的项在结论中不得周延。本文把直言命题中作为主项和谓项出现的词项处理成零元模态词,提出一个零元模态逻辑系统来精确定义周延这一概念,并论证这两条规则可以从该系统的内插定理直接导出,由此确立周延律的正确性。     

Supervaluationism and Logical Consequence: A Third Way

It is often assumed that the supervaluationist theory of vagueness is committed to a global notion of logical consequence, in contrast with the local notion characteristic of modal logics. There are, at least, two problems related to the global notion of consequence. First, it brings some counterexamples to classically valid patterns of inference. Second, it is subject to an objection related to higher-order vagueness. This paper explores a third notion of logical consequence, and discusses its adequacy for the supervaluationist theory. The paper proceeds in two steps. In the first step, the paper provides a deductive notion of consequence for global validity using the tableaux method. In the second step, the paper provides a notion of logical consequence which is an alternative to global validity, and discusses i) whether it is acceptable to the supervaluationist and ii) whether it plays a better role in a theory of vagueness in the face of the problems related to the global notion.     

On Hans Reichenbach’s inductivism

One of the first to criticize the verifiability theory of meaning embraced by logical empiricists, Reichenbach ties the significance of scientific statements to their predictive character, which offers the condition for their testability. While identifying prediction as the task of scientific knowledge, Reichenbach assigns induction a pivotal role, and regards the theory of knowledge as a theory of prediction based on induction. Reichenbach’s inductivism is grounded on the frequency notion of probability, of which he prompts a more flexible version than that of Richard von Mises. Unlike von Mises, Reichenbach attempts to account for single case probabilities, and entertains a restricted notion of randomness, more suitable for practical purposes. Moreover, Reichenbach developed a theory of induction, absent from von Mises’s perspective, and argued for the justification of induction. This article outlines the main traits of Reichenbach’s inductivism, with special reference to his book Experience and prediction.     

Probability, logic and the cognitive foundations of rational belief

Since Pascal introduced the idea of mathematical probability in the 17th century discussions of uncertainty and “rational” belief have been dogged by philosophical and technical disputes. Furthermore, the last quarter century has seen an explosion of new questions and ideas, stimulated by developments in the computer and cognitive sciences. Competing ideas about probability are often driven by different intuitions about the nature of belief that arise from the needs of different domains (e.g., economics, management theory, engineering, medicine, the life sciences etc). Taking medicine as our focus we develop three lines of argument (historical, practical and cognitive) that suggest that traditional views of probability cannot accommodate all the competing demands and diverse constraints that arise in complex real-world domains. A model of uncertain reasoning based on a form of logical argumentation appears to unify many diverse ideas. The model has precursors in informal discussions of argumentation due to Toulmin, and the notion of logical probability advocated by Keynes, but recent developments in artificial intelligence and cognitive science suggest ways of resolving epistemological and technical issues that they could not address.     

What is Carnap's Conventionalism after all?

As is well known, Carnap's conventionalism was a rejection to Kant's view ofmathematics and was fully developed in his Logische Syntax der Sprache.The purpose of this article is to step back to Der Logische Aufbau der Weltto show that the Logical Syntax of Language is an attempt to solve difficultiesfound in the earlier construction. I first clarify the notion of conventionalism, whichplays a central role in the application of mathematics to the reconstruction of empiricalknowledge. By not strictly distinguishing between the intuitive notion and thetopological concept of dimension, Carnap is led to a construction which is highlyquestionable. To illustrate the constructive method developed in the Aufbauand some of its inherent difficulties, I consider the computational aspects of theconstruction of phenomenological space via the mathematical concept of dimension.Contrary to Carnap's conventionalism, a dual nature of mathematical statements isbrought into existence by his logical reconstruction. So, if Carnap wants to retainhis mathematics as devoid of content, he must make a clear-cut distinction betweenanalytic and synthetic statements. Thus the natural follow-up to the Aufbau isthe Logical Syntax of Language.     

The Transcendental Method and (Post-)Empiricist Philosophy of Science

This paper reconsiders the relation between Kantian transcendental reflection (including transcendental idealism) and 20th century philosophy of science. As has been pointed out by Michael Friedman and others, the notion of a “relativized a priori” played a central role in Rudolf Carnap’s, Hans Reichenbach’s and other logical empiricists’ thought. Thus, even though the logical empiricists dispensed with Kantian synthetic a priori judgments, they did maintain a crucial Kantian doctrine, viz., a distinction between the (transcendental) level of establishing norms for empirical inquiry and the (empirical) level of norm-governed inquiry itself. Even though Thomas Kuhn’s theory of scientific revolutions is often taken to be diametrically opposed to the received view of science inherited from logical empiricism, a version of this basically Kantian distinction is preserved in Kuhn’s thought. In this respect, as Friedman has argued, Kuhn is closer to Carnap’s theory of linguistic frameworks than, say, W.V. Quine’s holistic naturalism. Kuhn, indeed, might be described as a “new Kant” in post-empiricist philosophy of science. This article examines, first, the relativization of the Kantian a priori in Reichenbach’s work, arguing that while Reichenbach (after having given up his original Kantianism) criticized “transcendentalism”, he nevertheless retained, in a reinterpreted form, a Kantian-like transcendental method, claiming that the task of philosophy (of science) is to discover and analyze the presuppositions underlying the applicability of conceptual systems. Then, some reflections on Kuhn’s views on realism are offered, and it is suggested that Kuhn (as well as some other influential contributors to the realism debate, such as Hilary Putnam) can be reinterpreted as a (relativized, naturalized) Kantian transcendental idealist. Given the central importance of Kuhnian themes in contemporary philosophy of science, it is no exaggeration to claim that Kantian transcendental inquiry into the constitutive principles of empirical knowledge, and even transcendental idealism (as the framework for such inquiry), still have a crucial role to play in this field and deserve further scrutiny.     

The effect of “irrelevant” variables on decision making: Criterion shifts in preferential choice?

In decision research, it is widely assumed that decision makers have subjective experiences which indicate definitively, albeit with random fluctuations, whether or not one alternative is preferable to another. Further, it is assumed that subjects' choices reflect this underlying preference order. It follows from this position, as a logical consequence rather than an empirical observation, that if a manipulation affects people's choices, it does so by changing the way people subjectively experience the alternatives (presumably via people's encoding or combination of attribute information). In psychophysics, an analogous theoretical position has been relinquished. Specifically, it is no longer believed that observers in a detection experiment have subjective experiences which indicate definitively, albeit with error, whether a signal has been perceived. Rather, according to signal detection theory, the observer's sensory experience can be portrayed as a quantifiable sensation that must be converted into an overt report of “signal present” or “signal absent” by comparing the sensation with a criterion. In this paper, we describe two models of preferential choice, the lexicographic criterion model and a probabilistic criterion model, that replace the notion of definitive preference with an analogue of signal detection theory. In the models, the decision maker is represented as having quantifiable inclinations, rather than definitive preferences, that must be converted into an overt choice by comparing the inclinations with a criterion. By attributing the effects of experimental manipulations to shifts in the criterion, rather than to changes in people's inclinations, the model offers a testable alternative to the proposition that altered choices imply altered preferences.     

A Logic for Disjunctive Ignorance

In this paper, we introduce a notion of ‘disjunctive ignorance’, which is a weak combination of two forms of ignorance in the literature. We propose a logical language with ‘disjunctive ignorance’ as a sole modality, explore the logical properties of this notion and its related notions, and axiomatize it over various frame classes. By finding suitable reduction axioms, we extend the results to the case of public announcements and apply it to Moore-like sentences.

     

Husserl on Analyticity and Beyond

Quine’s criticism of the notion of analyticity applies, at best, to Carnap’s notion, not to those of Frege or Husserl. The failure of logicism is also the failure of Frege’s definition of analyticity, but it does not even touch Husserl’s views, which are based on logical form. However, some relatively concrete number-theoretic statements do not admit such a formalization salva veritate. A new definition of analyticity based not on syntactical but on semantical logical form is proposed and argued for.

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On a fallacy attributed to tarski

The purpose of this paper is to examine some passages of Tarski‘s paper ’On the concept of logical consequence’ and to show that some recent readings of those passages are wrong. John Etchemendy has claimed that in those passages Tarski gave an argument purporting to show that the notion of logical consequence defined by him (as opposed to some pretheoretic notion of logical consequence) possesses certain modal properties. Etchemendy further claims that the argument he attributes to Tarski is fallacious. Some of Etchemendy’s critics have granted him that Tarski did give an argument purporting to show that the defined notion possesses certain modal properties ; but they have claimed that Tarski’s argument was not a fallacious one. I will show that both Etchemendy and his critics are wrong; in the relevant passages, Tarski did not offer (nor did he intend to offer) an argument that the defined notion of logical consequence possesses any modal properties     

Pragmatic reasoning schemas

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 (must, can) 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.     

Mental representation of logical connectives

Logical connectives, such as “AND”, “OR”, “IF . . . THEN”, and “IF AND ONLY IF” are ubiquitous in both language and cognition; however, reasoning with logical connectives is error-prone. We argue that some of these errors may stem from people's tendency to minimize the number of possibilities compatible with logical connectives and to construct a “minimalist” one-possibility representation. As a result, connectives denoting a single possibility (e.g., conjunctions) are likely to be represented correctly, whereas connectives denoting multiple possibilities (e.g., disjunctions or conditionals) are likely to be erroneously represented as conjunctions. These predictions were tested and confirmed in three experiments using different paradigms. In Experiment 1, participants were presented with a multiple-choice task and asked to select all and only those possibilities that would indicate that compound verbal propositions were true versus false. In Experiment 2, a somewhat similar task was used, except that participants were asked later to perform a cued recall of verbal propositions. Finally, Experiment 3 used an old/new recognition paradigm to examine participants' ability to accurately recognize different logical connectives. The results of the three experiments are discussed in relation to theories of representation of possibilities and theories of reasoning.     

Case study of a Thai conduction aphasic

A case study of a 55-year-old nonfamilial left-handed monolingual Thai patient with clinical and pathoanatomic evidence of major infarction in the left temporoparietal region is presented. He was studied at 9 years poststroke with a Thai adaptation of the Boston Diagnostic Aphasia Exam and supplementary tests. His language characteristics included fluent spontaneous speech, near-normal auditory language comprehension, and poor repetition, leading to a diagnosis of conduction aphasia. In regard to this aphasic syndrome, issues concerning classification, neuroanatomic correlates, and underlying neuropsychological mechanisms are addressed. The nature of his grammatical disturbance is examined critically in light of the notion of “information load.”     

为分析性辩护

自从蒯因在著名的《经验论的两个教条》等一系列文章中对分析性做出批评以后,分析传统内已经很少有哲学家再对分析性概念持肯定态度了;随之受到威胁的是意义以及逻辑必然性的概念。     

Human/nature: Toward a critical ecology

Abstract

Gadamer's notion of statements, distinguished from the otherwise speculative nature of language, is explored with regard to its implications for reflexivity in qualitative research. After reviewing the importance of ‘speculative’ language for phenomenological research, this paper discusses the problem that statements pose for phenomenological methods. The methodological challenges faced in trying to facilitate experiential accounts rather than statements are examined, with particular attention to the central role of the researcher‐participant conversation. The methodological implications of a conversational approach to phenomenological research are then presented, and this approach is discussed in terms of reflexivity.     

Attributive Uses of Prosentences

Defenders of the prosentential theory of truth claim that the English language contains prosentences which function analogously to their better known cousins – pronouns. Statements such as 'That is true' or 'It is true', they claim, inherit their content from antecedent statements, just as pronouns inherit their reference from antecedent singular terms. Prosentential theorists claim that the content of these prosentences is exhausted by the content of their antecedents. They then use the notion of the inheritance of content from an antecedent to explain the various functions of the predicate '…is true'. Defenders of the prosentential theory of truth are mistaken, I claim, in thinking that in order to oppose the view that '…is true' is used to ascribe a substantive truth property to propositions they need to claim that no uses of '…is true' ever attribute any property. I identify an 'attributive' use of prosentences in which reliability is implicitly attributed to a subject. I then use the capacity of prosentences to serve as implicit attributions of reliability as a basis for explicating the logical structure of explicit attributions of reliability. The identification of an attributive use of prosentences does not constitute a fundamental change in the prosentential theory.     

A Counterfactual Analysis of the Concepts of Logical Truth and Necessity

This paper analyzes the logical truths as (very roughly) those truths that would still have been true under a certain range of counterfactual perturbations.What’s nice is that the relevant range is characterized without relying (overtly, at least) upon the notion of logical truth. This approach suggests a conception of necessity that explains what the different varieties of necessity (logical, physical, etc.) have in common, in virtue of which they are all varieties of necessity. However, this approach places the counterfactual conditionals in an unfamiliar foundational role.     

Substantive and procedural norms in normative multiagent systems

Procedural norms are instrumental norms addressed to agents playing a role in the normative system, for example to motivate these role playing agents to recognize violations or to apply sanctions. Procedural norms have first been discussed in law, where they address legal practitioners such as legislators, lawyers and policemen, but they are discussed now too in normative multiagent systems to motivate software agents. Procedural norms aim to achieve the social order specified using regulative norms like obligations and permissions, and constitutive norms like counts-as obligations. In this paper we formalize procedural, regulative and constitutive norms using input/output logic enriched with an agent ontology and an abstraction hierarchy. We show how our formalization explains Castelfranchi's notion of mutual empowerment, stating that not only the agents playing a role in a normative system are empowered by the normative system, but the normative system itself is also empowered by the agents playing a role in it. In our terminology, the agents are not only institutionally empowered, but they are also delegated normative goals from the system. Together, institutional empowerment and normative goal delegation constitute a mechanism which we call delegation of power, where agents acting on behalf of the normative system become in charge of recognizing which institutional facts follow from brute facts.     

Aristotelian diagrams for semantic and syntactic consequence

Several authors have recently studied Aristotelian diagrams for various metatheoretical notions from logic, such as tautology, satisfiability, and the Aristotelian relations themselves. However, all these metalogical Aristotelian diagrams focus on the semantic (model-theoretical) perspective on logical consequence, thus ignoring the complementary, and equally important, syntactic (proof-theoretical) perspective. In this paper, I propose an explanation for this discrepancy, by arguing that the metalogical square of opposition for semantic consequence exhibits a natural analogy to the well-known square of opposition for the categorical statements from syllogistics, but that this analogy breaks down once we move from semantic to syntactic consequence. I then show that despite this difficulty, one can indeed construct metalogical Aristotelian diagrams from a syntactic perspective, which have their own, equally elegant characterization in terms of the categorical statements. Finally, I construct several metalogical Aristotelian diagrams that incorporate both semantic and syntactic consequence (and their interaction), and study how they are influenced by the underlying logical system’s soundness and/or completeness. All of this provides further support for the methodological/heuristic perspective on Aristotelian diagrams, which holds that the main use of these diagrams lies in facilitating analogies and comparisons between prima facie unrelated domains of investigation.