# Philosophy at Work (11 - 12 March 2019)

## Idea & Motivation

The workshop continues the series of workshops held either at the University of Salzburg, or the University of California/Irvine or at LMU Munich.

The topics presented at the workshop cover a wide variety of mathematical philosophy: philosophy of logic, inductive logic, game theory, general philosophy of science, and special philosophy of science -- just to mention a few.

## Speakers

- Bengt Autzen (Salzburg/MCMP)
- Jeff Barrett (UC Irvine)
- Norbert Gratzl (LMU/MCMP)
- Simon Huttegger (UC Irvine)
- Silvia Jonas (LMU/MCMP)
- Hannes Leitgeb (LMU/MCMP)
- Toby Meadows (UC Irvine)
- Julien Murzi (Salzburg/MCMP)
- Patricia Palacios (Salzburg/MCMP)
- Lauren Ross (UC Irvine)
- Marta Sznajder (LMU/MCMP)
- Charlotte Werndl (Salzburg)

## Program

### Day 1 (11 March 2019)

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

09:30 - 10:00 | Welcome/Coffee |

10:00 - 11:00 | Silvia Jonas: Realism and Disagreement |

11:05 - 12:05 | Patricia Palacios: Can Physics Tell Us When Democratic Systems May Be Unstable? |

12:05 - 13:30 | Lunch Break |

13:30 - 14:30 | Charlotte Werndl: Can Somebody Please Say What Gibbsian Statistical Mechanics Says? |

14:35 - 15:35 | Jeff Barrett: Quantum Randomness and Underdetermination |

15:35 - 16:00 | Coffee Break |

16:00 - 17:00 | Lauren Ross: Causes with Material Continui |

17:05 - 18:05 | Simon Huttegger: Rethinking Convergence to the Truth |

18:30 | Conference Dinner (Schlosswirtschaft Schwaige) |

### Day 2 (12 March 2019)

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

09:30 - 10:30 | Bengt Autzen: Hope and Risk |

10:40 - 11:40 | Toby Meadows: Anodyne Set-Theoretic Multiversism |

11:45 - 12:45 | Hannes Leitgeb: A Structural Justification of Probabilism: From Partition Invariance to Subjective Probability |

12:45 - 14:00 | Lunch Break |

14:00 - 15:00 | Marta Sznajder: Joanina Hosiasson on Inductive Reasoning |

15:05 - 16:05 | Julien Murzi: Surprise, Surprise, KK is Innocent! |

16:05 - 16:25 | Coffee Break |

16:25 - 17:25 | Norbert Gratzl: Proof-theoretic Semantics and Classical Logic (with a Glimpse on Arithmetic) |

## Abstracts

### Bengt Autzen: Hope and Risk

Luc Bovens argues that hope has instrumental value in counteracting risk aversion. The paper revisits Bovens' decision-theoretic argument regarding the value of hope. The aim of the paper is to refine the hope-counteracts-risk aversion thesis by clarifying the conditions under which it holds. I argue that the value of hope when making decisions in the face of risk must be more subtle than previously assumed. In order for hope to be of instrumental value in countering risk aversion, a hopeful agent must take into account whether gambles are cumulative or compounding in character.top

### Jeff Barrett: Quantum Randomness and Underdetermination

We consider the nature of quantum randomness and how one might have empirical evidence for it. We will see why, depending on one's computational resources, it may be impossible to determine whether a particular notion of randomness properly characterizes one's empirical data. Indeed, we will see why even an ideal observer under ideal epistemic conditions may never have any empirical evidence whatsoever for believing that the results of one's quantum-mechanical experiments are randomly determined. This illustrates a radical sort of empirical underdetermination faced by fundamentally stochastic theories like quantum mechanics.top

### Norbert Gratzl: Proof-theoretic Semantics and Classical Logic (with a Glimpse on Arithmetic)

This talk takes up the topic of a philosophically satisfying presentation of classical logic—viewed from proof-theoretic semantics. The starting point is a minimal logic which is known to satisfy the desiderata from proof-theoretic semantics. It is then shown how to obtain classical logic by adding certain rules that will result in classical logic and satisfy the desiderata in question— all except cut elimination. The last item will be accomplished by a hybrid system that has both elements of classical and minimal logic. Finally, consistency of classical arithmetic is established by use of game theoretic semantics and previously obtained results.top

### Simon Huttegger: Rethinking Convergence to the Truth

Convergence to the truth is viewed with some ambivalence in philosophy of science. On the one hand, methods of inquiry that lead to the truth in the limit are prized as marks of scientific rationality. But an agent who, by using some method, expects to always converge to the truth seems to fail a minimum standard of epistemic modesty. This point was recently brought home by Gordon Belot in his critique of Bayesian epistemology. In this paper I will study convergence to the truth theorems within the framework of Edward Nelson's radically elementary probability theory. This theory provides an enriched conceptual framework for investigating convergence, giving rise to an appropriately modest from of Bayesianism.top

### Silvia Jonas: Realism and Disagreement

The fact that people disagree fundamentally on moral matters is widely considered to be a central problem for moral realism. However, explicit arguments spelling out what exactly the problem with disagreement is supposed to be are scarce. As a consequence, some moral realists have argued that disagreement does in fact not constitute a problem for realism. Drawing an analogy with mathematics, I argue that it is possible to substantiate the claim that fundamental disagreement is problematic for moral realism. More precisely, I argue that disagreement undermines realism about an a priori domain just in case pluralism is not a coherent option.top

### Hannes Leitgeb: A Structural Justification of Probabilism: From Partition Invariance to Subjective Probability

A new justification of Probabilism is developed that pays close attention to the structure of the underlying space of possibilities. Its central assumption is: rational numerical degrees of belief ought to be partition-invariant. One can prove that if the resulting set of postulates for graded belief is satisfied, rational degrees of belief may always be represented as probabilities. The justification is compared to, and contrasted with, Cox’s (1946, 1961), and it is shown that some features of subjective probability theory appear in new light once partition invariance is counted amongst the constitutive properties of rational graded belief.top

### Toby Meadows: Anodyne Set-Theoretic Multiversism

Is there more than one way to faithfully interpret the language of set theory? In the last few years, a number of affirmative answers to this question have been entertained by both set theorists and philosophers.

Depending on who you talk to, the impact of these multiverse moves tends to be dramatically over-stated or almost deceptively underestimated. In an effort to disentangle these mixed messages, I will try to draw out something approximating the core contention of a variety of multiverse positions. To this end, I will introduce an inoffensive species of multiversism and argue that whether or not one holds this position is of almost negligible mathematical importance. Indeed you might already be an Anodyne Multiverser and just not know it!top

### Julien Murzi: Surprise, Surprise, KK is Innocent!

(joint work with Leonie Eichhorn and Philipp Mayr)

The surprise examination paradox seemingly shows that a teacher cannot give a surprise test to her students. Yet, she obviously can. Where does the paradoxical reasoning go wrong? In his book Knowledge and its Limits (2000, ch. 6), Tim Williamson argues by a supposed analogy with some paradoxes based on margin for error principles that the surprise reasoning relies on an illicit application of the KK principle, that if S knows P, then she knows that she knows P. In this talk, I argue that Williamson’s argument from analogy is problematic, and observe that invalidating the KK principle is in any event of no use: a paradoxical conclusion is reached before such a principle is applied in the course of the paradoxical reasoning. Indeed, there is no need to invalidate the KK principle in order to block the surprise reasoning. Following Sorensen (1988), I show that a more adequate solution diagnoses a tension between a certain knowledge retention principle and the existence of blindspots for knowledge.top

### Patricia Palacios: Can Physics Tell Us When Democratic Systems May Be Unstable?

I examine the extant literature in econophysics and sociophysics modeling, in particular models for stock market crashes, voting contagion and Galam models for democratic voting in bottom up hierarchical systems, and suggest that they can be interpreted as minimal models (Weisberg 2007, Batterman and Rice 2014). I conclude that these highly idealized minimal models aid us in identifying possible interventions (á la Woodward 2003) and can help us explain how democracy is destabilized.

top

### Lauren Ross: Causes with Material Continuity

A significant amount of philosophical literature on causation has focused on criteria that distinguish causal from non-causal relationships. This focus has generated interest in accounts of causation that appeal to statistical relations, counterfactual analyses, notions of conserved quantities, and theories of connected processes, among others. Despite this interest, a more recent body of work in this area has taken a different aim. Instead of distinguishing causal from non-causal relationships, this work aims to clarify differences across types of causal relationships. This newer work captures “distinctions among causation” in the sense of iden- tifying how legitimate causal relationships can differ from each other. These projects often suggest that these differences matter for how we reason about causal relationships and for how we study, understand, and represent them. Among the different characteristics that causal relationships can have, differences having to do with stability, specificity, proportion- ality, and speed have been discussed in the extant literature (Woodward 2010; Blanchard, Vasilyeva, and Lombrozo 2018; Ross 2018).

In this talk, I argue that there is another distinction among causal relationships that has yet to receive attention in the literature. This distinction has to do with whether causal relationships have material continuity or not. In this sense, “material continuity” refers to the transfer or flow of some material from cause to effect. This feature shares similarities to various causal process and “mark transmission” accounts of causation, such as those articulated by Russell, Reichenbach, and Salmon (Russsell 1948; Reichenbach 1971; Salmon 1984). After discussing key features of these accounts and various examples from biology and ordinary life, I provide an analysis of how we should understand causes with material continuity. In particular, I clarify (i) what is meant by material continuity, (ii) how it is present in some but not all causal relationships, and (iii) why this feature matters for how causal relationships are understood, studied, and described.top

### Marta Sznajder: Joanina Hosiasson on Inductive Reasoning

In a series of articles written in the 1920s and 1930s, Janina Hosiasson explored various topics in the logic of inductive reasoning. Influenced by Broad, Keynes, and the logic of the Lwów-Warsaw School, she insisted on a logical treatment of induction, while at the same time drawing on her empirical research on the psychology of reasoning. In this talk, I will discuss Hosiasson's work on analogical reasoning; the presentation will be largely based on unpublished archive material. I will analyse her general approach to inductive reasoning and her definition of analogical reasoning, comparing it to modern approaches. Through an analysis of the necessary and sufficient conditions that Hosiasson derives for the justification of inductive reasoning, I will show how her work foreshadows some proposals made twenty years later by Carnap and others.

top

### Charlotte Werndl: Can Somebody Please Say What Gibbsian Statistical Mechanics Says?

Gibbsian statistical mechanics (GSM) is the most widely used version of statistical mechanics among working physicists. Yet a closer look at GSM reveals that it is unclear what the theory actually says and how it bears on experimental practice. The root cause of the difficulties is the status of the Averaging Principle, the proposition that what we observe in an experiment is the ensemble average of a phase function. We review different stances toward this principle, and eventually present a coherent interpretation of GSM that provides an account of the status and scope of the principle.top

## Registration

## Venue

Carl Friedrich von Siemens Stiftung

Südliches Schloßrondell 23

80638 Munich

## Acknowledgement

The workshop is supported by the Carl Friedrich von Siemens Stiftung.