Field on the Normative Role of Logic

Aristotelian Society Supplementary Volume, 2009

The paper tries to spell out a connection between deductive logic and rationality, against Harman's arguments that there is no such connection, and also against the thought that any such connection would preclude rational change in logic. One might not need to connect logic to rationality if one could view logic as the science of what preserves truth by a certain kind of necessity (or, by necessity plus logical form); but the paper points out a serious obstacle to any such view. What is the connection between (deductive) logic and rationality? Answers to this vary markedly.

Theoria. An International Journal for Theory, History and Foundations of Science, 2023

This paper advocates for the normative role of logic in reasoning. I offer a response, anchored in an externalist perspective, to two fronts of attack against the normativity thesis, namely Harman’s sceptical challenge and the accusation of naturalistic fallacy. On the one hand, I rework dialogical bridge principles and show that such principles satisfy adequacy criteria to deal with Harman’s challenge. On the other hand, I argue that it is possible to derive normative consequences from logical facts. This is because argumentative interactions among agents involve the acceptance of constitutive rules that entail obligations. Hence, since logical rules can be seen as constitutive of the social practice of reasoning, they create prescriptions for reasoning. Bridge principles make those obligations and prohibitions explicit.

Aristotelian Society Supplementary Volume, 2009

The paper tries to spell out a connection between deductive logic and rationality, against Harman's arguments that there is no such connection, and also against the thought that any such connection would preclude rational change in logic. One might not need to connect logic to rationality if one could view logic as the science of what preserves truth by a certain kind of necessity (or by necessity plus logical form); but the paper points out a serious obstacle to any such view.

pre-print, 2023

Logical theories are usually seen as true or false in relation to the phenomenon they aim to describe, namely, validity. An alternative view suggests that the laws governing validity are "legislated-true," making logical theories conventional. In this chapter, I propose an intermediate standpoint in which logical systems exhibit a blend of descriptive and conventional aspects, balanced to fulfill their primary purpose, which is not seen as theoretical, but practical: assisting us in generating and identifying valid inferences. From this perspective, logics are cognitive tools, human creations designed primarily to facilitate the performance of cognitive operations. This viewpoint aligns logic more closely with technology than science and supports a pluralistic approach: the diversity of alternative technical solutions for issues related to the creation and recognition of valid inferences allows for the coexistence of multiple logics.

Logic and Logical Philosophy, 2011

In this paper two concepts of psychologism in logic are outlined: the one which Frege and Husserl fought against and the new psycholo-gism, or cognitivism, which underlies a cognitive turn in contemporary logic. Four issues such cognitively oriented logic should be interested in are indicated. They concern: new fields opened for logical analysis , new methods and tools needed to address these fields, neural basis of logical reasoning, and an educational problem: how to teach such logic? Several challenging questions, which arise in the context of these issues, are listed.

In this paper two concepts of psychologism in logic are outlined: the one which Frege and Husserl fought against and the new psychologism, or cognitivism, which underlies a cognitive turn in contemporary logic. Four issues such cognitively oriented logic should be interested in are indicated. They concern: new fields opened for logical analysis, new methods and tools needed to address these fields, neural basis of logical reasoning, and an educational problem: how to teach such logic? Several challenging questions, which arise in the context of these issues, are listed.

Rough draft. To appear in Knauff, M. and Spohn, W. (ed.), Handbook of Rationality, MIT Press.

This chapter addresses the question as to how (if at all) propositional (PL) and first-order logic (FOL) relate to epistemic rationality. Rationality, it is often held, demands that our attitudes cohere in particular ways. Logic is often invoked as a source of such coherence requirements when it comes to belief: An ideally rational agent's beliefs are consistent and closed under logical consequence. However, this traditional picture has been challenged from various quarters. We begin by briefly reviewing the key concepts involved in PL and FOL. We then critically examine two distinct approaches to justifying logic-based requirements of rationality. The first lays down a set of desiderata codifying our intuitions, and then seeks to formulate a principle articulating the link between logic and rational belief that satisfies them. The second starts by identifying our most fundamental epistemic aim and seeks to derive requirements of rationality based on their ability to promote this aim.

2021

Contemporary psychologism has been amended for most of the objections by its opponents over a century ago. However, some authors still raise doubts about its ability to account for some peculiar properties of logic. In particular, it is argued that the psychological universality of patterns of inferential behavior is not sufficient to account for the normativity of logic. In this paper, I deal with the issue and offer three alternative solutions that do not rely on mere empirical universality. I will use the works of Laurence Jonathan Cohen, Diego Marconi and Marcello D'Agostino, adapting them for the purpose of defending logical psychologism. I will therefore argue that, although more refined work on the subject is needed, contemporary psychologism has the key resources to retain its place in the philosophical debate on the foundations of logic.

Memory & Cognition, 1983