Carnegie Mellon University

Lectures & Colloquia

Fall 2015

Monday, September 14, 2015, Philosophy Colloquium

Katie Steele, London School of Economics
International Paretianism: A palatable response to climate change?
Talk: 3:30p-5:15p, DH 1212, Reception: 5:15p-6:00p, DH 4301

International Paretianism (IP) is billed as the positive and feasible response to international problems such as climate change (see, especially, Posner and Weisbach 2010). In the tradition of public goods economics, climate change is depicted as a collective-action problem for nation states, where the current ‘business-as-usual’ arrangement is Pareto inferior to some alternative involving climate-change mitigation. According to IP, a global climate deal should be framed to achieve such a Pareto improvement (making no state worse off). Critics argue, however, that such a deal would not be adequately just, and moreover, to the extent that it supports substantial mitigation, IP involves inconsistent claims about feasibility. This paper contributes to the debate by initially clarifying what would be achieved by an IP response to climate change, under various assumptions about the game theoretic structure of the problem and two possible stances on feasibility. The further consideration is whether an IP deal plausibly has some merit, however minimal, in terms of advancing justice.

Monday, October 12, 2015, Philosophy Colloquium

Nate Charlow, University of Toronto
Talk Title: "The Meaning of Imperatives"
Talk: 3:30p-5:15p, DH 1212, Reception: 5:15p-6:00p, DH 4301

Abstract: I will survey a range of current views on the semantics of imperatives, presenting them as more or less conservative with respect to the "Truth-Conditional Paradigm" in semantics. I will describe and critique views at either extreme of this spectrum: accounts on which the meaning of an imperative is a modal truth-condition, as well as various accounts that attempt to explain imperative meaning without making use of truth-conditions. On the view I end up defending, an imperative will semantically determine, without having as its meaning, a modal truth-condition, which figures centrally in accounting for various aspects of its meaning.

Note: This talk shares a title (and abstract) with a published paper of mine, but it is very different in focus.

Assistant Professor, Department of Philosophy, University of Toronto
Current Research Areas: Phil Lang/semantics:imperatives; expressivism; conditionals; modals

Monday, October 19, 2015, Pure and Applied Logic Colloquium

Dana Scott, Carnegie Mellon University (emeritus)
Talk title: "Can Modalities Save Naive Set Theory?”
Talk: 3:30p-5:15p, DH 1212, Reception: 5:15p-6:00p, DH 4301

Abstract: The late “Grisha” Mints once asked the speaker whether a naive set theory could be consistent in modal logic. Specifically he asked whether restricting the comprehension scheme to necessary properties was safe. Scott was working on a set theory in the Lewis system S4 of modal logic and Mints was happy to position his question in the same modal system. Obviously a very, very weak modality can avoid paradoxes, but such results are not especially interesting. At that time (2009) Scott could not answer the consistency question, and neither could Mints. Last November Scott noted that CMU Philosophy was hosting a seminar on a naive set theory by Harvey Lederman. Scott wrote him for his paper and said, “By the way, there is this question of Grisha Mints, and I wonder if you have an opinion?” Lederman sent back a sketch of a proof of the inconsistency of a strengthened version of comprehension. That proof at first did not quite work out, but was repaired in correspondence. Lederman mentioned the questions to two of his colleagues, and in March of 2015 Tiankai Liu suggested a possible model of a weaker comprehension scheme, which after a small correction gave a consistency proof. A few days later, Peter Fritz came up with essentially the same model. A paper has now been submitted for publication jointly by Fritz, Lederman, Liu, and Scott.

Monday, November 9, 2015, Philosophy Colloquium

Cailin O'Connor, University of California-Irvine
Talk Title: The Evolution of Guilt: a Model-Based Approach
Talk: 3:30p-5:15p, DH 1212, Reception: 5:15p-6:00p, DH 4301

Abstract: Moral emotions, such as shame and guilt, are deeply important to human moral behavior. Although few ethicists think the 'is' of evolved moral emotions should be directly translated to an 'ought' of ethical imperative, evidence from psychology and biology has increasingly made clear that at very least a full picture of human ethics must take these emotions into account.

This paper will focus on the evolution of guilt specifically. The goal is to provide an analysis of how guilt can be individually beneficial to actors, drawing on extensive literature from evolutionary game theory regarding the evolution of prosocial behavior. In this way, work by philosophers on the evolution of guilt can be supplemented by a more detailed picture of the relevant evolutionary dynamics. As I will show, this literature suggests a number of ways that guilt can provide individual fitness benefits, both by preventing transgression in the first place, and by leading to reparative behaviors after transgression. In an attempt to better understand this latter role of guilt, I present novel modeling work on the evolution of apology.

Monday, November 23, 2015, Pure and Applied Logic Colloquium

Peter Dybjer, Chalmers University, Gothenburg, Sweden
Talk Title: Undecidability of Equality in the Free Locally Cartesian Closed Category
Talk: 3:30p-5:15p, DH 1212

Abstract: We show that a version of Martin-Löf type theory with extensional identity, a unit type $\N_1, \Sigma, \Pi$, and a base type is a free category with families (supporting these type formers) both in a 1- and a 2-categorical sense. It follows that the underlying category of contexts is a free locally cartesian closed category in a 2-categorical sense because of a previously proved biequivalence. We then show that equality in this category is undecidable by reducing it to the undecidability of convertibility in combinatory logic.  This is joint work with Simon Castellan and Pierre Clairambault, ENS Lyon.

Monday, November 30, 2015, Philosophy Colloquium

James Owen Weatherall, University of California, Irvine
Talk Title: On Stuff: The Field Concept in Classical and Quantum Physics
Talk: 3:30p-5:15p, DH 1212, Reception: 5:15p-6:00p, DH 4301

Abstract: Discussions of physical "ontology" often come down to two basic options. Either the basic physical entities are particles, or else they are fields. I will argue that, in fact, it is not at all clear what it would mean to say that the world consists of fields. Speaking classically (i.e., non-quantum-ly), there are many different sorts of thing that go by the name "field", each with different representational roles. Even among those that have some claim to being "fundamental" in the appropriate sense, it does not seem that a single interpretational strategy could apply in all cases. I will end by suggesting that standard strategies for constructing quantum theories of fields are not sufficiently sensitive to the different roles that "fields" can play in classical physics. Along the way, I will say something about an old debate in the foundations of relativity theory, concerning whether the spacetime metric is a "geometrical" or "physical" field. The view I will defend is that the metric is much like the electromagnetic field: geometrical!

Spring 2016

Monday, February 1, 2016, Center for Ethics and Policy Colloquium

Christine Grady, National Institutes of Health
Talk Title: The Art and Science of Contemporary Informed Consent
Talk: 3:30-5:15p, HH B103, Reception: 5:15p-6:00p, DH 4301

Abstract:  Informed consent is a core ethical and legal requirement in medical care and clinical research, based on a principle of respect for individuals’ right to shape their goals and choices consistent with their values and interests. Yet there is disparity between the practice of informed consent and its theoretical ideal, and an under-appreciation of how informed consent varies by context.  A growing body of research has documented gaps in patient and research participant understanding, and an overemphasis on the written consent document. I will present data on studies we and others have done in an effort to improve research participant understanding of study information. I will also consider the advantages and drawbacks of different proposed models of consent, such as dynamic consent, opt-out consent, and broad consent.  Opportunities for strengthening the concepts and practices of informed consent will be discussed. 

Monday, February 8, 2016, Pure and Applied Logic Colloquium

Audrey Yap, University of Victoria, BC
Talk Title: Emmy Noether and the History of Mathematical Structuralism: Invariants and Ideals
Talk: 3:30p-5:15p, HH B103, Reception: 5:15p-6:00p, DH 4301

Abstract:  In Hermann Weyl's obituary of Emmy Noether, he identifies several different periods in her work in which she transitions through different methodological styles. Though she began her career studying under Paul Gordan, and working in an algorithmic, constructive style (her early work), she truly grew into her own as an algebraist, having been encouraged to study abstract algebra by Ernst Fischer. In the second period Weyl identifies, Noether worked on invariant theory, some of which comprised her Habilitation work, but then turned to the theory of ideals, which is arguably one of her most important mathematical contributions. We will consider how her structural approach to mathematics developed as her work on invariant theory transitioned away from the algorithmic Gordan style of calculating invariants. Though in many ways, her contributions to ideal theory are extensions of work that had already been done by others, most notably Dedekind, this structural approach and a greater range of mathematical tools allowed her to generalize Dedekind’s work to great effect. It is exactly her emphasis on generalization that embodies her pioneering approach to abstract algebra. Her student B.L van der Waerden writes that the maxim by which she always let herself be guided was that "all relations between numbers, functions, and operations become clear, generalizable, and truly fruitful only when they are separated from their particular objects and reduced to general concepts." This paper will show how Noether's emphasis on abstraction and generalization of frameworks and results contributed to the more abstract conception of structure used in contemporary mathematics. 

Monday, February 22, 2016, Philosophy Colloquium

Kenny Easwaran, Texas A&M University
Talk Title: A New Framework for Aggregating Utility
Talk: 3:30p-5:15p, HH B103, Reception: 5:15p-6:00p, DH 4301

Abstract: It is often assumed that a natural way to aggregate utility over multiple agents is by addition. When there are infinitely many agents, this leads to various problems. Vallentyne and Kagan approach this problem by providing a partial ordering over outcomes, rather than a numerical aggregate value. Bostrom and Arntzenius both argue that without a numerical value, it is difficult to integrate this aggregation into our best method for considering acts with risky outcomes: expected value.

My 2014 paper, "Decision Theory without Representation Theorems", describes a project for evaluating risky acts that extends expected value to cases where it is infinite or undefined. The project of this paper is to extend this methodology in a way that deals with risk and aggregation across agents simultaneously, instead of giving priority to one or the other as Bostrom and Arntzenius require. The result is still merely a partial ordering, but since it already includes all considerations of risk and aggregation, there is no further need for particular numerical representations.

Monday, March 28, 2016, Philosophy Colloquium

Anita Allen, University of Pennsylvania
Talk Title: Beware of Iphones and Artists:  Is there an Ethical Duty to Protect Your Own Privacy?
Talk: 3:30p-5:15p, HH B103, Reception: 5:15p-6:00p, DH 4301

Abstract: Safeguarding others' privacy is widely understood to be a responsibility of government, business, and individuals.   (Apple seems to think protecting device owners’ privacy is a corporate responsibility.)  Do individuals also have a moral obligation to protect their own privacy?  Moreover, could protecting one's own privacy be called for by important moral virtues, as well as obligations or duties? The "virtue" of fairness and the "duty" or "obligation" of respect for persons arguably ground other-regarding responsibilities of confidentiality and data security. But is anyone ethically required (and not just prudentially advised) to protect his or her own privacy? If so, how might a requirement to protect one's own privacy and related ethical virtues properly influence everyday choices, public policy, or the law?  Shop offline with cash?  Don’t use an Iphone?  Avoid open windows?  I want to test the idea of an ethical mandate to protect one's own privacy in the world that includes the Internet of Things, while identifying the practical and philosophical problems that bear adversely on the case. 

Monday, April 4, 2016, Philosophy Colloquium

Igor Douven, Paris-Sorbonne University
Talk: 3:30p-5:15p, HH B103, Reception: 5:15p-6:00p, DH 4301

Monday, April 18, 2016, Pure and Applied Logic Colloquium

Peter Aczel, University of Manchester
Talk Title: On the NF Consistency Problem
Talk: 3:30p-5:15p, HH B103, Reception: 5:15p-6:00p, DH 4301

Abstract:  In 1937 Quine first presented the formal set theory called New Foundations (NF). It is a subtheory of the inconsistent Set Theory that is in the standard first order language of axiomatic set theory and consists of the full naive comprehension scheme together with the extensionality axiom. NF weakens the comprehension scheme by restricting it to only apply to stratifiable formulae; i.e. those formulae in which natural number 'levels' can be attached to its variables in such a way that for every subformula, (x in y), where x has level n, y must have level n+1. So, for example, 'not (x in x)' is not stratifiable.

The problem to decide whether or not NF is consistent is still open.
But at present there are two independent unpublished claims to have consistency proofs, one by Randall Holmes and the other by Jamie Gabbay. In my talk I will review some of the history of the problem and give my own reformulation of some of the ideas that I feel I have understood, in the claimed proof of Jamie that has been submitted for publication in a nearly 90 page paper,

Jamie's proof is based on techniques from Nominal Theory and Stone Duality which I consider are not essential. So my presentation will not involve them. Also I will not try to go into the tricky combinatorial details involved in two original transfinite recursive constructions used in Jamie's model construction that I do not claim to have checked in all details.

Monday, April 18, 2016, Center for Ethics and Policy Colloquium

Ruth Macklin, Albert Einstein College of Medicine
Talk Title: Cross-border Surrogacy: Exploitation of Women or Employment Opportunity?
Talk: 4:30p-6:00p, Margaret Morrison 103

Abstract:  A global industry of medical “tourism” has flourished in recent years.  A prominent example is cross-border surrogacy arrangements, in which women who cannot carry a pregnancy travel to low-resource countries where typically poor women are paid to be gestational surrogates.  In most cases an embryo that has been fertilized in vitro using the visiting woman’s egg and her partner’s sperm is implanted in the womb of the surrogate.  However, surrogacy arrangements have also taken place for gay male couples as well as single women. This practice has been criticized as exploitation of poor women by wealthier couples who come from mostly industrialized countries.  Yet the women who serve as gestational surrogates are paid more than they could possibly earn in other types of work.  Critics argue that large sums of money “coerce” poor women into an activity that places them at some risk and involves significant inconvenience.  Are women who serve as surrogates--or their families--actually better off as a result of their serving in this capacity?  The ethics of cross-border surrogacy is hotly debated, with additional questions arising about the legal status of the resulting child.

Venue Details

Hamerschlag Hall (HH) B103: Enter Hamerschlag Hall at the main entrance (Wean Hall on the right and Baker-Porter Hall on the left), proceed down the main corridor. At the end of the hallway make a left and take the silver elevators to level B. When you exit the elevator, make a right and HH B103 is at the end of this hall on the left.

Using the stairways: Enter Hamerschlag Hall at the main entrance proceed down the main corridor. At the end of the hallway make a right and walk down from level 1 to level B. On level B make a right and HH B103 is at the end of this hall on the left.

Doherty Hall 4301: Enter Doherty Hall through the side entrance, to the right of the Bill Brown Gathering Area. The 4301 wing is at the very top of the first stairway you encounter. Alternatively, pass the stairway into an alcove and take the left-hand elevator to the 4th floor. When you exit the elevator you are in 4301.