Soames on the logical empiricists on truth,meaning, convention,and logical truth

Philosophical Studies -     

Natural deduction and arbitrary objects

Journal of Philosophical Logic -     

Classical harmony: Rules of inference and the meaning of the logical constants

The thesis that, in a system of natural deduction, the meaning of a logical constant is given by some or all of its introduction and elimination rules has been developed recently in the work of Dummett, Prawitz, Tennant, and others, by the addition of harmony constraints. Introduction and elimination rules for a logical constant must be in harmony. By deploying harmony constraints, these authors have arrived at logics no stronger than intuitionist propositional logic. Classical logic, they maintain, cannot be justified from this proof-theoretic perspective. This paper argues that, while classical logic can be formulated so as to satisfy a number of harmony constraints, the meanings of the standard logical constants cannot all be given by their introduction and/or elimination rules; negation, in particular, comes under close scrutiny.     

Literal meaning, conventional meaning and first meaning

Literal meaning is often identified with conventional meaning. In A Nice Derangement of Epitaphs Donald Davidson argues (1) that literal meaning is distinct from conventional meaning, and (2) that literal meaning is identical to what he calls first meaning. In this paper it is argued that Davidson has established (1) but not (2), that he has succeeded in showing that there is a distinction between literal meaning and conventional meaning but has failed to see that literal meaning and first meaning are also distinct. This failure is somewhat surprising, since it is through a consideration of Davidson's notion of radical interpretation that the distinction between literal meaning and first meaning becomes apparent.I am grateful to the Social Sciences and Humanities Research Council of Canada for its financial support, and to Mark Mercer, Tom Patton and Gary Wedeking for their helpful comments. I would also like to thank David Checkland, who discussed A Nice Derangement of Epitaphs with me at length some years ago.     

Reassessing logical hylomorphism and the demarcation of logical constants

The paper investigates the propriety of applying the form versus matter distinction to arguments and to logic in general. Its main point is that many of the currently pervasive views on form and matter with respect to logic rest on several substantive and even contentious assumptions which are nevertheless uncritically accepted. Indeed, many of the issues raised by the application of this distinction to arguments seem to be related to a questionable combination of different presuppositions and expectations; this holds in particular of the vexed issue of demarcating the class of logical constants. I begin with a characterization of currently widespread views on form and matter in logic, which I refer to as ‘logical hylomorphism as we know it’—LHAWKI, for short—and argue that the hylomorphism underlying LHAWKI is mereological. Next, I sketch an overview of the historical developments leading from Aristotelian, non-mereological metaphysical hylomorphism to mereological logical hylomorphism (LHAWKI). I conclude with a reassessment of the prospects for the combination of hylomorphism and logic, arguing in particular that LHAWKI is not the only and certainly not the most suitable version of logical hylomorphism. In particular, this implies that the project of demarcating the class of logical constants as a means to define the scope and nature of logic rests on highly problematic assumptions.     

Instability, Modus ponens and uncertainty of deduction

Considering the instability of nonlinear dynamics, the deductive inference rule Modus ponens itself is not enough to guarantee the validity of reasoning sequences in the real physical world, and similar results cannot necessarily be obtained from similar causes. Some kind of stability hypothesis should be added in order to draw meaningful conclusions. Hence, the uncertainty of deductive inference appears to be like that of inductive inference, and the asymmetry between deduction and induction becomes unrecognizable such as to undermine the basis for the fundamental cleavage between analytic truth and synthetic truth, as W. V. O. Quine pointed out. Induction is not inferior to deduction from a pragmatic point of view.     

Modality,invariance, and logical truth

Conclusion Let us sum up. We began with the question, What is the interest of a model-theoretic definition of validity? Model theoretic validity consists in truth under all reinterpretations of non-logical constants. In this paper, we have described for each necessity concept a corresponding modal invariance property. Exemplification of that property by the logical constants of a language leads to an explanation of the necessity, in the corresponding sense, of its valid sentences. I have fixed upon the epistemic modalities in characterizing the logical constants: to be a logical constant in the language of a population is to be invariant over a modality describing complete possible epistemic states of that population (or an idealized analogue thereof). The grounds for this characterization are these: (1) It leads, I believe, to an extensionally reasonable demarcation of the logical constants, including clear cases and excluding clear non-cases. It gives a principled criterion for deciding unclear cases. (2) It provides an analysis of the topic-neutrality of logic. (3) It leads to an explanation of the epistemic necessity of the logical truths in terms of the topic-neutrality of the logical constants.All the same, it is reasonable to ask, even if the suggested demarcation of logic is extensionally correct, whether it can reasonably be expected to be fundamental. The epistemic invariance of an expression is a rather striking property, one which we should want to explain. What is missing, then, is an explanation of the distinguishing epistemic properties of the constants in terms of more fundamental properties involving their understanding and use. It would be these that properly define the nature, not just the extent, of logic.     

Logical expressivism,logical theory and the critique of inferences

Synthese - The basic idea of logical expressivism in the Brandomian tradition is that logic makes inferential relations explicit and thereby accessible to critical discussion. But expressivists...     

Relevant implication and the weak deduction theorem

It is shown that the implicational fragment of Anderson and Belnap's R, i.e. Church's weak implicational calculus, is not uniquely characterized by MP (modus ponens), US (uniform substitution), and WDT (Church's weak deduction theorem). It is also shown that no unique logic is characterized by these, but that the addition of further rules results in the implicational fragment of R. A similar result for E is mentioned.I am grateful to the referees; their comments enabled me to correct a mistake and to clarify several passages.     

Struggle with ultimate meaning: Nuanced associations with search for meaning,presence of meaning,and mental health

Struggle with ultimate meaning reflects concerns about whether one’s life has a deeper meaning or purpose. We examined whether this construct could be distinguished from presence of meaning in life and search for meaning. In two US samples – a web-based sample (N = 1047) and an undergraduate sample (N = 3978) – confirmatory factor analyses showed that struggle with ultimate meaning loaded on a factor that was distinct from but related to presence (negatively) and search (positively). Moderated regression analyses showed that people with low levels of presence combined with high levels of search for meaning were particularly likely to struggle with ultimate meaning. Additionally, when compared to presence and search, struggle with ultimate meaning related more strongly to depressive symptoms than presence or search. These results suggest that struggle with ultimate meaning represents a distinct component of how people grapple with meaning that has implications for mental health.