Prawitz has recently developed a theory of epistemic grounding that differs in many respects from his earlier semantics of arguments and proofs. An innovative approach to inferences yields a new conception of the intertwinement of the notions of valid inference and proof. We aim at singling out three reasons that may have led Prawitz to the ground-theoretic turn, i.e.: a better order in the explanation of the relation between valid inferences and proofs; a notion of valid inference based on which (...) valid inferences and proofs are recognisable as such; a reconstruction of the deductive activity that makes inferences capable of yielding justification per se. These topics are discussed by Prawitz with reference to a very general and ancient question: why and how correct deduction has the epistemic power to compel us to accept its conclusions, provided its premises are justified? We conclude by remarking that, in spite of some improvements, the ground-theoretic approach shares with the previous one a problem of vacuous validity which, as Prawitz himself points out, blocks in both cases a satisfactory explanation of epistemic compulsion. (shrink)

Dag Prawitz’s theory of grounds proposes a fresh approach to valid inferences. Its main aim is to clarify nature and reasons of their epistemic power. The notion of ground is taken to denote what one is in possession of when in a state of evidence, and valid inferences are described in terms of operations that make us pass from grounds we already have to new grounds. Thanks to a rigorously developed proof-as-chains conception, the ground-theoretic framework permits Prawitz to overcome some (...) conceptual difficulties of his earlier proof-theoretic explanation. Though from different points of view, anyway, the two accounts share an issue of recognizability of relevant operational properties. (shrink)

Celebrated as a courtesan and poet, and as a woman of great intelligence and wit, Tullia d'Aragona entered the debate about the morality of love that engaged the best and most famous male intellects of sixteenth-century Italy. First published in Venice in 1547, but never before published in English, Dialogue on the Infinity of Love casts a woman rather than a man as the main disputant on the ethics of love. Sexually liberated and financially independent, Tullia d'Aragona dared (...) to argue that the only moral form of love between woman and man is one that recognizes both the sensual and the spiritual needs of humankind. Declaring sexual drives to be fundamentally irrepressible and blameless, she challenged the Platonic and religious orthodoxy of her time, which condemned all forms of sensual experience, denied the rationality of women, and relegated femininity to the realm of physicality and sin. Human beings, she argued, consist of body and soul, sense and intellect, and honorable love must be based on this real nature. By exposing the intrinsic misogyny of prevailing theories of love, Aragona vindicates all women, proposing a morality of love that restores them to intellectual and sexual parity with men. Through Aragona's sharp reasoning, her sense of irony and humor, and her renowned linguistic skill, a rare picture unfolds of an intelligent and thoughtful woman fighting sixteenth-century stereotypes of women and sexuality. (shrink)

We define a class of formal systems inspired by Prawitz’s theory of grounds. The latter is a semantics that aims at accounting for epistemic grounding, namely, at explaining why and how deductively valid inferences have the power to epistemically compel to accept the conclusion. Validity is defined in terms of typed objects, called grounds, that reify evidence for given judgments. An inference is valid when a function exists from grounds for the premises to grounds for the conclusion. Grounds are described (...) by formal terms, either directly when the terms are in canonical form, or indirectly when they are in non-canonical form. Non-canonical terms must reduce to canonical form, and two terms may be said to be equal when they converge towards equivalent grounds. In our systems these properties can be proved through rules distinguished according to whether they concern types or logic. Type rules involve type introduction and elimination, equality for application of operational symbols, and re-writing equations for non-canonical terms. The logic amounts to a sort of intuitionistic system in a Gentzen format. To conclude, we show that each system of our class enjoys a normalization property. (shrink)

One of Etchemendy's arguments against the Tarskian and model-theoretic notion of logical truth is based on a reduction principle according to which a universally quantified sentence is true if, and only if, all of its instances are logically true. The reduction of logical truth to mere truth reveals that the concept of validity at play in Tarski and in model-theory relies upon extra-logical assumptions. A similar reduction had already been put forward by Prawitz, although not with focus on extra-logical assumptions. (...) Prawitz's reduction concerns rather the possibility of understanding the Tarskian and model-theoretic approach as implying any epistemic modality. We take into account a possible strategy that an advocate of Tarski and model-theory may use against Etchemendy's objection, and argue that this strategy fails with respect to Prawitz's criticism. This permits us to shed light upon a difference between Prawitz's and Etchemendy's standpoints: while Etchemendy's reduction shows that the Tarskian and model-theoretic notion of logical truth cannot be understood as an adequate formal counterpart of truth-preservation solely by virtue of logical form, Prawitz's reduction insists on the fact that truth-preservation solely by virtue of logical form is insufficient for epistemic modality to obtain. (shrink)

We outline a class of term-languages for epistemic grounding inspired by Prawitz’s theory of grounds. We show how denotation functions can be defined over these languages, relating terms to proof-objects built up of constructive functions. We discuss certain properties that the languages may enjoy both individually and with respect to their expansions. Finally, we provide a ground-theoretic version of Prawitz’s completeness conjecture, and adapt to our framework a refutation of this conjecture due to Piecha and Schroeder-Heister.

ABSTRACTThis paper explores the impact of the philosophical structure of Leone Ebreo’s Dialoghi d’amore on the construction of Tullia d’Aragona’s Dialogo della infinità di amore. Analysing both the explicit references to and the indirect citations of Leone’s Dialoghi, I aim to demonstrate how the reinterpretation of some fundamental topics of this work – such as the re-evaluation of the sensual aspect of human love and the distinction between honest and vulgar love – lies at the heart of Tullia’s dialogue. The (...) article also intends to shed light on the complex role of Benedetto Varchi in the elaboration of these issues by d’Aragona, who for the final revision of her text could have relied – as she did for her poems – on his collaboration. (shrink)

This book presents an in-depth and critical reconstruction of Prawitz’s epistemic grounding, and discusses it within the broader field of proof-theoretic semantics. The theory of grounds is also provided with a formal framework, through which several relevant results are proved. Investigating Prawitz’s theory of grounds, this work answers one of the most fundamental questions in logic: why and how do some inferences have the epistemic power to compel us to accept their conclusion, if we have accepted their premises? Prawitz proposes (...) an innovative description of inferential acts, as applications of constructive operations on grounds for the premises, yielding a ground for the conclusion. The book is divided into three parts. In the first, the author discusses the reasons that have led Prawitz to abandon his previous semantics of valid arguments and proofs. The second part presents Prawitz’s grounding as found in his ground-theoretic papers. Finally, in the third part, a formal apparatus is developed, consisting of a class of languages whose terms are equipped with denotation functions associating them to operations and grounds, as well as of a class of systems where important properties of the terms can be proved. (shrink)

Few philosophical topics are as intertwined with gender questions as the topic of love, which moved center-stage in the diverse literary and philosophical productions of the Renaissance. Situated in the rich cultural environment of Cinquecento, Italy, Tullia d'Aragona's Dialogo della Infinità d'Amore offers not only a unique contribution to Renaissance theories of love, but also forces a reexamination of the aims and methods of communication, and provokes a reflection on philosophy's very own self-conception.

: Few philosophical topics are as intertwined with gender questions as the topic of love, which moved center-stage in the diverse literary and philosophical productions of the Renaissance. Situated in the rich cultural environment of Cinquecento, Italy, Tullia d'Aragona's Dialogo della Infinità d'Amore offers not only a unique contribution to Renaissance theories of love, but also forces a reexamination of the aims and methods of communication, and provokes a reflection on philosophy's very own (male) self-conception.

This paper explains how to use a new software tool for argument diagramming available free on the Internet, showing especially how it can be used in the classroom to enhance critical thinking in philosophy. The user loads a text file containing an argument into a box on the computer interface, and then creates an argument diagram by dragging lines from one node to another. A key feature is the support for argumentation schemes, common patterns of defeasible reasoning historically know as (...) topics . Several examples are presented, as well as the results of an experiment in using the system with students in a university classroom. (shrink)

Robert Kimball, in “What’s Wrong with Argumentum Ad Baculum?” (Argumentation, 2006) argues that dialogue-based models of rational argumentation do not satisfactorily account for what is objectionable about more malicious uses of threats encountered in some ad baculum arguments. We review the dialogue-based approach to argumentum ad baculum, and show how it can offer more than Kimball thinks for analyzing such threat arguments and ad baculum fallacies.

Peirce and Frege both distinguished between the propositional content of an assertion and the assertion of a propositional content, but with different notational means. We present a modification of Peirce’s graphical method of logic that can be used to reason about assertions in a manner similar to Peirce’s original method. We propose a new system of Assertive Graphs, which unlike the tradition that follows Frege involves no ad hoc sign of assertion. We show that axioms of intuitionistic logic can be (...) derived from AGs, and argue that AGs analyse and represent assertions and illocutionary content in a way which is motivated both by its logical properties and its historical connection with the ideas that led to the development of the graphical method. (shrink)