# Normativity, Logic, and Reasoning (27 May 2023)

## Idea & Motivation

Talks in this workshop will address questions that are in the center of recent debates of the normativity of logic and reasoning.

## Speakers

- Matteo De Benedetto (Bochum)
- Bruno Jacinto (Lisbon)
- Alessandra Marra (MCMP)
- Edi Pavlovic (MCMP)
- Allie Richards (Lisbon)
- Tyko Schuff (MCMP)
- Hosea von Hauff (MCMP)
- António Zilhão (Lisbon)

## Program

Time | Event |
---|---|

09:45 - 10:00 | Welcome |

10:00 - 11:00 | Bruno Jacinto: Rationality, Logic and Information |

11:10 - 12:10 | António Zilhão: On Doxastic Akrasia |

12:10 - 13:30 | Lunch |

13:30 - 14:30 | Allie Richards: Normativity, Default Logic and Bridge Principles |

14:40 - 15:40 | Edi Pavlovic: Is, Ought, and Cut |

15:40 - 16:10 | Coffee |

16:10 - 17:10 | Hosea von Hauff & Tyko Schuff: Logical Pluralism and Normativity |

17:15 - 18:15 | Matteo De Benedetto & Alessandra Marra: Sound and Feasible Inferences: A bounded rationality approach to the normativity of logic |

19:00 | Dinner |

## Abstracts

### Bruno Jacinto: Rationality, Logic and Information

According to the information-theoretic account of belief and knowledge (Stampe 1979, Dretske 1981, Stalnaker 1984, Millikan 1989), the content of these attitudes is determined by the extent to which an agent's belief states carry information about her environment. In this talk I will formulate my preferred version of the information-theoretic account - which extends the original account with, among other things, a topic-sensitive conception of belief states and an explication of epistemic normativity. I will then inquire into what are the bridge principles relating claims of logical consequence to norms governing beliefs that are supported by the resulting information-theoretic epistemology. Finally, I will consider some strategies for how this information-theoretic epistemology may account for mathematical knowledge acquired through deduction.

### António Zilhão: On Doxastic Akrasia

There are a number of fundamental issues associated with the problem of doxastic, or epistemic, akrasia. First, there is the issue of how to appropriately define the condition that is meant to be identified by such a term. Assuming that one becomes satisfied with one or other of the candidate definitions, one has yet to face the subsequent problem of determining whether or not the condition thus identified is, as a mater of fact, at all possible. Assuming that a positive answer to this problem can be found, a further question still remains: can doxastic or epistemic akrasia be a rational condition to be in? I’ll address the above mentioned issues in my talk sequentially and try to come up with sensible answers to all of them.

### Allie Richards: Normativity, Default Logic and Bridge Principles

A common strategy used for defending the normative role of logic is connecting the notion of logical validity to intuitive norms about

reasoning. Macfarlane (2004) famously provides a categorization of such bridge principles with varying parameters, and assesses which of those principles are true. Following Macfarlane, in this talk I assess which bridge principles (if any) are true, but argue for a weaker consequence relation. In doing so, I use John Horty’s (2012) default logic framework.

### Edi Pavlovic: Is, Ought, and Cut

In this paper we examine a range of deontic logics and their philosophical motivations. We distinguish syntactically between normative and descriptive statments and show, using proof-theoretic methods, that for the entire range it is a (meta)theorem that the Special Hume Thesis holds, namely that no purely normative conclusion follows non-trivially from purely descriptive premises (nor, in fact, vice versa). In this way we identify a metanormative constraint which allows us to dismiss certain arguments as unconvincing based simply on their form. We continue with a discussion of possible bridge principles between the two types of statments, and finally lay out further work.

### Hosea von Hauff & Tyko Schuff: Logical Pluralism and Normativity

There is an apparent conflict between logical pluralism, the view that there is more than one correct logic and the canonical edict that logic is normative. If two logics disagree with regard to the validity of some argument, but both of them are correct in the sense of the pluralist, what then should a rational agent do?

In order to escape this dilemma we propose a novel perspective on what it is that differs from one logic to another: Different logics are about different subject matters, and accordingly they bear normative strength only relative to the epistemic interests of the reasoning agent.

One possible incarnation of such a pluralism would be the view that classical logic is concerned with necessary truth preservation, while intuitionistic logic is concerned with constructability, and relevance logic is concerned with warranted assertibility. Depending on which property we are interested in, different logics may be normatively binding for our reasoning.

### Matteo De Benedetto & Alessandra Marra: Sound and Feasible Inferences: A bounded rationality approach to the normativity of logic

We present a novel approach to the question of the normativity of logic, which we reinterpret as a clash between two intuitions: the direct normativity intuition and the unfeasibility intuition. Building upon theories of bounded rationality, our approach conceptualizes reasoning as constrained by multiple, independent normative factors, logical and non-logical ones. These different factors can conflict with one another, to the effect that logically sound inferences might not coincide with what is feasible for an agent to infer. From this perspective, we will argue that logic gives us only prima facie obligations on what to believe, but that such obligations do not always coincide with what an agent ought to believe all things considered. These distinctions will dissolve the alleged clash between the direct normativity and the unfeasibility intuition, embedding logical normativity within a fine-grained theory of human rationality.

### topRegistration

Please register sending an email to Office.Leitgeb@lrz.uni-muenchen.de.

## Organizer

## Venue

Prof.-Huber-Pl. 2

80539 München**Lehrturm, Room W401**

## LMU Roomfinder

https://www.lmu.de/raumfinder/#/building/bw0420/map?room=042204401_