Melinda A. Roberts — Scholarship

Research interests include population ethics; the obligations we have in respect of future people as well as people who will never exist at all; the procreative asymmetry; the neutrality intuition; the nonidentity problem; the repugnant conclusion; and wrongful life.

Melinda A. Roberts — Books

  • How We Read the Law (in progress)
  • A Dialogue Concerning  the Nonidentity Problem (in progress)
  • The Existence Puzzles:  An Introduction to Population Ethics.  (Oxford University Press, forthcoming 2023)

This book introduces newcomers to population ethics, a relatively new branch of moral philosophy that asks how moral law addresses distinctions in how many people, and just who, will exist in the future. This book also proposes a new way of thinking about the hard cases that population ethics is so widely known for. An intuitive first pass at what moral law has to say about the choice to bring new people into existence to begin with comes from Narveson. We are “in favour of making people happy” (we can call that the basic maximizing intuition) but are “neutral about making happy people” (the basic existential intuition). Ever since population ethics started attracting intense interest just a few decades ago, the dominant narrative has been that the two intuitions exist in high tension—that they are inconsistent—and that, as between the two, it’s the basic existential intuition that must go. That unfortunate conclusion ties our hands both in addressing climate change and in establishing the moral permissibility of and constitutional right to contraception and earlier abortion. Moreover, it demands grave sacrifices from multitudes of existing and future people in exchange for the bare chance to avoid human extinction indefinitely. This book takes a different tack. It considers hard cases to generate, not counterexamples disproving the basic existential intuition, but puzzles we can solve by application of the puzzle-solving rules we all understand: fitting the pieces together without throwing any of them out and within the confines of conceptual necessity.

  • Abortion and the Moral Significance of Merely Possible Persons:  Finding Middle Ground in Hard Cases, in Philosophy and Medicine (Springer 2010)

This book has two goals.  The first is to give an account, called Variabilism, of the moral significance of merely possible persons who, relative to a particular circumstance, or possible future or world, could but in fact never do exist.  The second is to use Variabilism to illuminate abortion.  According to Variabilism, merely possible persons just like anyone else matter morally but matter variably.  Where we understand that a person incurs a loss whenever agents could have created more wellbeing for that person and instead create less, Variabilism asserts that the moral significance of any loss is a function of where that loss is incurred in relation to the person who incurs it.  That is:  a loss incurred at a world where the person who incurs that loss does or will exist has full more significance, according to Variabilism, while a loss incurred by that same person at a world where that person never exists at all has no moral significance whatsoever. Some other views deem all merely possible persons and all of their losses to matter morally.  Still other views deem no merely possible persons and none of their losses to matter morally.  Variabilism, instead, takes a middle ground between these two extreme positions.  It thus opens the door to a certain middle ground on procreative choice in general and abortion in particular.  Thus, given that, for persons, thinking and coming into existence come together, Variabilism supports the argument that the early abortion is ordinarily permissible when it is what the woman wants.  That is so, since the loss incurred when, as an effect of the early abortion, a given person is never brought into existence to begin with has no moral significance at all.  In contrast, the late abortion is ordinarily subject to a different analysis.  For the loss incurred in that case has full moral significance, according to Variabilism, since it is incurred at a world where the person who incurs it already exists. Abstract at Springer

  • Harming Future Persons:  Ethics, Genetics and the Nonidentity Problem, eds. Melinda A. Roberts and David T. Wasserman, in International Library of Ethics, Law, and the New Medicine (Springer 2009)

Includes papers by Heyd (explaining and defending the person-affecting intuition and relating nonidentity problem to issues of biographical identity), Persson and McMahan (on the Asymmetry), Holtug (proposing a solution to the nonidentity problem with elements sufficiently person-affecting to sidestep the repugnant conclusion), Wolf (on identity), Mulgan (on a rule consequentialist solution to the nonidentity problem), Harman and Steinbock (on when it is wrong to bring the harmed child into existence), Hanser (on standing in an appropriate relation to the harmed child as a condition on causing harm), Roberts (on analogies between one type of nonidentity problem and the two-envelope problem, and approaches to each that focus on the information available to the agent at the critical time), Lillehammer, Herissone-Kelly and Wasserman (on considerations relating to attitude, intention and parental role as helping to the nonidentity problem), Arrhenius (on structural and coherence issues relating to the person-affecting approach generally) and Peters and Shiffrin (on the nonidentity problem, law and public policy).  Abstract at Springer

  • Child Versus Childmaker:  Future Persons and Present Duties in Ethics and the Law (Rowman & Littlefield 1998)

Chap. 1.  Introduction

Chap. 2:  Is the Person-Affecting Intuition Inconsistent? — John Broome has argued that the person-affecting intuition is inconsistent.  I develop an alternative statement of the person-affecting intuition — a form of person-affecting consequentialism — that avoids that inconsistency objection.  Based on the four-place relation “p has at least as much wellbeing in w1 as q does in w2,” the principles I suggest focus on maximizing wellbeing not for the aggregate but rather for individual.  Thus for each existing or future person, the proposal is that, with exceptions to address trade-offs, agents ought to make choices that maximize that person’s wellbeing.

Chap. 3:  The Nonidentity Problem — Derek Parfit, Gregory Kavka and others put forth the “nonidentity problem” as a challenge to person-affecting principles generally.  I consider how three variations on the nonidentity problem apply to the form of person-affecting consequentialism I describe in Chap. 2.  My conclusion is that two variations of the nonidentity problem are inconsistent with the basic tenets of person-affecting consequentialism and can be safely set aside, and that the third variation leads to results that are not implausible.

Chap. 4:  Wrongful Life — I argue that in some instances the choice to bring a new person into existence can harm a person — create, that is, less wellbeing for a person when agents could have created more — and that that harm can ground a finding of wrongdoing.  I thus argue that it is sometimes better for a person never to come into existence at all than to come into an existence that is highly flawed.

Chap. 5:  Human Cloning — John Robertson has argued that “harm to offspring” objections fail in the case of the new reproductive technologies.  His argument derives from the ideas that (i) in the absence of the new technologies the offspring would not exist at all and (ii) the offspring lives are worth living.  Robertson’s conclusion is that offspring in general are not harmed, or wronged, by application of those new technologies.  I argue that when cloning is used to produce — say — five, or fifty, or a thousand genetically identical people, we can see just how agents could have gone about making things better for any one of those people.  They could have brought one embryo, but not all those others, to fruition.  We, accordingly, find that we have a clear basis after all for declaring the cloned individual to have been harmed.

Melinda A. Roberts — Papers, Discussions, Reviews

  • “Incommensurability, Intuition and Existence,” Proceedings of Climate Ethics and Future Generations (Vol. V) (Institute for Futures Studies Preprint Series 2023)
  • “The Person Based Intuition and the Better Chance Puzzle,” The Oxford Handbook of Population Ethics, eds. Gustaf Arrhenius, Krister Bykvist and Tim Campbell (Oxford University Press, 2022)
  • “The Value and Probabilities of Existence,” Existence and Ethics eds. Jeff McMahan, Tim Campbell, James Goodrich and Keton Ramakrishnan (Oxford University Press, 2022).  Pp. 38-60
  • “Anonymity and Indefinitely Iterated Addition and Reversal,”  Proceedings of Climate Ethics and Future Generations, eds. Paul Bowman and Joe Roussos (Vol. IV) (Institute for Futures Studies 2021).  Pp. 221-237.  https://www.iffs.se/en/publications/working-papers/studies-on-climate-ethics-and-future-generations-vol-4/
  • “Does Climate Change Put Ethics on a Collision Course with Itself?”  Proceedings of Climate Ethics and Future Generations, eds. Paul Bowman and Katharina Berndt Rasmussen (Vol. III), (Institute for Futures Studies 2021).  Pp. 197-220.   https://www.iffs.se/en/publications/working-papers/studies-on-climate-ethics-and-future-generations-vol-3/
  • “Consequentialism and Population Ethics,” The Oxford Handbook of Consequentialism, ed. Douglas Portmore (Oxford University Press 2020).  Pp. 474-497
  • “What Is the Right Way to Make A Wrong a Right?” Proceedings of Climate Ethics and Future Generations, eds. Paul Bowman and Katharina Berndt Rasmussen (Vol. II) (Institute for Futures Studies 2020).  https://www.iffs.se/en/publications/working-papers/studies-on-climate-ethics-and-future-generations-vol-2/
  • “Parfit, Population Ethics and Pareto Plus,” Parfit’s Reasons and Persons:  An Introduction and Critical Inquiry (Reading Parfit Part II), ed. Andrea Sauchelli (Routledge 2020)
  • “Why Wear Blinders?  Boonin and the Narrow Approach to the Nonidentity Problem.”  Book symposium, David Boonin, The Non-Identity Problem and the Ethics of Future People in Law, Ethics and Philosophy (ed. Erik Magnusson) vol. 7 (2019) pp. 102-126.  https://www.raco.cat/index.php/LEAP
  •  “The Nonidentity Problem” (Stanford Encyclopedia of Philosophy 2019).  https://plato.stanford.edu/entries/nonidentity-problem/
  • “Population,” International Encyclopedia of Ethics (Wiley-Blackwell 2019)
  • “Nonidentity Problem,” International Encyclopedia of Ethics.  Wiley-Blackwell (2019)
  •  “When Does the Worth-Having Existence Make Things Better?”  Proceedings of Climate Ethics and Future Generations, eds. Paul Bowman and Katharina Berndt Rasmussen (Vol. I) (Institute for Futures Studies, 2019), pp. 27-41.  https://www.iffs.se/en/publications/working-papers/studies-on-climate-ethics-and-future-generations-vol-1/
  • “Getting Clear on Why the Benefits of Existence Do Not Compel Us to Create” (peer commentary), The American Journal of Bioethics 17(8) (2017), pp. 18-21
  • Review of Rivka Weinberg, The Risk of a Lifetime (Oxford 2016) Ethics 127(2) (2017) 512-517
  • “Is a Person-Affecting Solution to the Nonidentity Problem Impossible?  Axiology, Accessibility and Additional People,” Canadian Journal of Philosophy (special issue Ethics and Future Generations, ed. Rahul Kumar) 47(2-3) (2017), pp. 200-228
  • “Dividing and Conquering the Nonidentity Problem,” with David Wasserman, in Current Controversies in Bioethics, eds. Matthew Liao and Collin O’Neil (Routledge 2017), pp. 81-98
  • “Population Axiology,” Oxford Handbook of Value Theory, eds. Iwao Hirose and Jonas Olson (Oxford University Press) (2015), pp. 299-323
  • Review of Nils Holtug, Persons, Interest and Justice (Oxford 2010) Utilitas (accepted August 2014)
  • Review of Ingmar Persson and Julian Savulescu, Unfit for the Future:  The Need for Moral Enhancement (Oxford 2012).  Journal of Moral Philosophy (accepted July 2014) — JMP link
  • “Can Procreation Impose Morally Significant Harms or Benefits on the Child?  And So What If It Can?”  Newsletter on Philosophy and Medicine (American Philosophical Association April 2014)
  • “Temkin’s Essentially Comparative View, Wrongful Life and the Mere Addition Paradox” (symposium) Analysis 74(2) (2014), pp. 306-326
  • “The Nonidentity Problem,” Stanford Encyclopedia of Philosophy (2013)
  • “The Nonidentity Problem,” International Encyclopedia of Ethics, ed. Hugh LaFollette (Wiley-Blackwell 2013)
  • “Population Ethics,” International Encyclopedia of Ethics, ed. Hugh LaFollette (Wiley-Blackwell 2013)
  • “Moral and Legal Constraints on Human Reproductive Cloning,” in Families:  Beyond the Nuclear Ideal:  For Better or Worse?  eds. D. Cutas and S. Chan (Bloomsbury 2012)
  • “Does the Nonidentity Problem Imply a Double Standard for Physicians and Patients?” Response to Hope and McMillan, American Journal of Bioethics (2012)
  • “An Asymmetry in the Ethics of Procreation,”  Philosophy Compass 6.11 (2011) 765-776
  • “Harming in the Multiple Agent Context,” Ethical Perspectives 18 (2011) 313-340
  • “The Asymmetry:  A Solution,” Theoria 77 (2011) 333-367
  • “Procreation, Abortion and Harm:  Comment” —  2.9 Newsletter on Philosophy and Medicine 20-23 (American Philosophical Association 2010)
  • “The Nonidentity Problem,” Stanford Encyclopedia of Philosophy (July 2009) — http://plato.stanford.edu/
  • “The Nonidentity Problem and the Two-Envelope Problem.” In Harming Future Persons, eds. Melinda A. Roberts and David T. Wasserman (Springer 2009), pp. 201-228.

The nonidentity problem and the two envelope problem have in common an ongoing resistance to intuitive analysis.  They also share certain structural features.  I argue that the two problems proceed under the same error, imagining subjects to draw haphazardly from a potpourri of actual and expected values to generate results about betterness and harm rather than, as we naturally do and always should, draw in a more discriminating way from a more orderly array.  When we play by the same set of rules in calculating the values that we then compare, we, in particular, become able to discern (1) harm in just the cases in respect of which one important variation on the nonidentity problem has long been thought to show no harm done and (2) no harm done in the two envelope problem, which purports to show harm done when the subject refuses endlessly to switch from one envelope to another and back again.

  • “Harming Future Persons:  Introduction,” with David T. Wasserman.  In Harming Future Persons, eds. Melinda A. Roberts and David T. Wasserman (Springer 2009), pp. viii-xxxviii.
  • “The Nonidentity Fallacy:  Harm, Probability and Another Look at Parfit’s Depletion Example,” 19 Utilitas 267-311 (2007)

The nonidentity problem is a collection of problems having distinct logical features. For that reason, they can be typed. This paper focuses on just one type of nonidentity problem, the can’t-expect-better problem, which includes Derek Parfit’s depletion example and many others. The can’t-expect-better problem uses an assessment about the low probability of any particular persons coming into existence to reason that an earlier wrong act does not harm that person. This paper argues that that line of reasoning is unusually treacherous in that it makes not just one hard-to-detect error in what is done with the relevant probability assessments but rather alternates between two. We sort out one mistake only to fall, against all odds (as it were), into a second. By avoiding both errors, we become able to discern harm in cases in which the can’t-expect-better problem argues there is none. We will then be in a position to set aside the can’t-expect-better problem as an objection against the person-based intuition that acts that are bad must be bad for at least some existing or future person.

  • Review, Tim Mulgan Future People:  A Moderate Consequentialist Account, 116 Mind 770-775 (2007)
  • “Supernumerary Pregnancy, Collective Harm and Two Forms of the Nonidentity Problem,” 34 Journal of Law, Medicine & Ethics 277-292 (2007)

An interesting question, in both the moral and the legal context, is whether the babies born of an infertility treatment-induced supernumerary (or multi-fetal) pregnancy (or ITISP) are properly considered to have been harmed.  One might wonder how such a question could even arise in the face of data that clearly demonstrate that ITISP leaves an unduly large number of babies blind, deaf and palsied and facing life-long disabilities.  In fact, however, a number of arguments, based on the problem of collective harm and two forms of the so-called nonidentity problem, challenge the claim of harm in the ITISP context.  The purpose of the present paper is to establish, as against these arguments, that harm has been imposed on the ITISP-damaged offspring.

  • “Person-Based Consequentialism and the Procreation Obligation,” The Repugnant Conclusion: Essays in Population Ethics (eds. J. Ryberg and T. Tannsjo) 99-128 (Springer, 2005)

This article explores a person-based account of the repugnant conclusion, investigating, along the way, the “extinction problem” as a leading challenge to such an account.  The argument is made that a careful consideration of what we understand our own obligations to be in contemporary life — including our obligations with respect to already-existing people — casts doubt on the idea that, in general, agents have an obligation to bring new people into existence just in case doing so will contribute to total, aggregate, utility or wellbeing.

  • “Supernumerary Pregnancy and the Limits of the Constitutional Privacy Guaranty,” Jo. of Philosophical Research 105-117(2005)

The claim of this article is that the privacy guaranty of the Fourteenth Amendment does not protect the choice to commence or continue a supernumerary pregnancy when the consequence of doing so presents risks of harm to prospective offspring in the form of physical, intellectual or emotional deficiencies.  This is so, it is argued, notwithstanding the fact that the reproductive choice (for example, the use of strong fertility drugs in the absence of procedures designed to avoid multiple pregnancy) is part of the causal chain that eventuates in the existence of those offspring, who (probably) would never have otherwise existed at all.

  • “Is the Person-Affecting Intuition Paradoxical?” 55 Theory and Decision 1-44 (2003)

This article critically examines some of the inconsistency objections that have been raised by John Broome and Larry Temkin against the so-called “person-affecting” restriction in normative ethics, including “additional people” problems (especially the mere addition paradox and issues relating to “Pareto-Plus”) and a version of the nonidentity problem from Kavka and Parfit.  Paradoxes can be avoided, it is argued, by situating the person-affecting intuition within a certain form of maximizing consequentialism (in competition with “total” and “average” forms of maximizing consequentialism).

  • “Can It Ever Have Been Better Never to Have Existed At All?  Person-Based Consequentialism and a New Repugnant Conclusion,” 20 Jo. of Applied Philosophy 159-185 (2003)

This article critically considers a handful of arguments to the conclusion that statements purporting to assert that never having existed at all can be better, in the case of some individuals, than existence are always incoherent or at least untrue.  The article concludes that such arguments fail and that it is both coherent and plausibly true that it would have been better, in the case of certain persons, that they never have existed at all.

This paper argues that a person-affecting, or “person-based,” form of consequentialism includes the best features of traditional, aggregative forms of maximizing consequentialism yet is not vulnerable to many of the most telling objections such forms of consequentialism.  Among other things, person-based consequentialism leaves a clearly defined role for considerations of equality.  This paper also suggests that the “leximin” principle captures much of what we think is right about equality without taking us too far in the direction of “equalism.”

  • “Cloning and Harming:  Children, Future Persons and the ‘Best Interest’ Test,” 13 Notre Dame Jo. of Law, Ethics & Public Policy 37-61 (1999)

We can predict that, should reproductive cloning ever become an option, we adults will insist on the right of consent before we will allow our own genomes to be used for purposes of reproductive cloning.  Whether conceived of in legal or moral terms, what we aim to protect in insisting on a right of consent is an interest in “privacy.”  This article argues that the same interest should be respected in the case of children and future persons.  Just as we would not (and in many states legally should not) use a child — who is in no position to consent — as a kidney donor unless we are sure that acting as such a donor is in the child’s own best interest, I argue that neither children nor future persons should be used as clone sources or intentionally brought into existence as clones — as one of two or more genetically identical individuals — unless there is a clear showing that such a violation of their interest in privacy serves their own best interest.

  • “Human Cloning:  A Case of No Harm Done?” 21 Jo. of Med. and Phil. 537-54 (1996)

The focus of this article is the nonidentity problem, developed by Parfit, Kavka and others, and its application to reproductive cloning technologies.  John Robertson has put forward a version of the nonidentity problem as an argument that reproductive cloning will not cause harm to the offspring that it will be used to produce.  Richard McCormack has argued that the acceptance of human reproductive cloning would undermine the dignity of the human embryo and would constitute a breach of the respect that he thinks we owe to the embryo as human.  The terms of their debate suggests that one must either support human reproductive cloning or reject abortion as a morally permissible option.  I argue, however, that we can identify respects in which reproductive cloning causes specific sorts of harm to offspring and hence that we have grounds to reject human reproductive cloning that have no adverse implication for our full and robust support for the right of abortion.

  • “Parent and Child in Conflict: Between Liberty and Responsibility,” 10 Notre Dame Jo. of Law, Ethics and Public Policy 485-542 (1996)

The focus of this article is the case of “Baby Richard,” who, after a failed adoption, was returned at the age of four to a biological father whom the child had never seen before.  The main argument of the article is that, just as adults have parental rights that we think warrant protection under the Fourteenth Amendment’s due process guaranty, so should children be understood to have “affiliational” rights that likewise merit constitutional protection.  Such rights would counterbalance in extreme circumstances the parent’s right of custody and control with respect to his or her own biological offspring.

  • “Present Duties and Future Persons: When Are Existence-Inducing Acts Wrong?” 14 Law and Philosophy 297-327 (1995)

This article takes a close look at the nonidentity problem in its many forms.  Thus, counterfactual, probabilistic and more broadly modal forms of the argument are considered and, in some cases, rejected as flawed.  The analysis has been revised and clarified in Chapter 3 of Child Versus Childmaker (“The Nonidentity Problem”).

  • “Sexual Harassment, the Acquiescent Plaintiff and the Unwelcomeness Requirement,” in D. Bushnell, ed., Nagging Questions (Rowman & Littlefield, 1995) 105-121
  • “A Way of Looking at the Dalla Corte Case,” 22 Jo. of Law, Medicine and Ethics 339-42 (1994)

I argue that, when the postmenopausal woman’s own ongoing partner is the sperm source, it is difficult to conclude that postmenopausal pregnancy is somehow immoral or should be made illegal.  This argument leaves the question of moral status open in the case were both egg and sperm are donated.  In both cases, the main concern would be the consequences of the technology for the child.  In the former case, it is difficult to see any other reasonable alternative by which the particular child could both exist and not suffer the risk of having a beloved parent die when the child is still young.  In the latter case, it is easy to pinpoint an alternative course of action that would allow the particular child both to exist and avoid the risk.  The moral analysis thus seems to be different in the one case as compared to the other.

  • “Good Intentions and a Great Divide: Having Babies by Intending Them,” 12 Law and  Philosophy 287-317 (1993)

The focus of this article is commercial surrogacy and Richard Posner’s argument that, from the child’s point of view, no objection to commercial surrogacy can be sensibly made in view of the fact that the child owes his or her very existence to the practice of surrogacy.  I argue that this defense of surrogacy is flawed in view of the fact that by the time the question of the contract’s enforceability is properly raised the child exists; declaring the contract unenforceable will not in any way change that fact.  At the same time, declaring the contract unenforceable represents a step forward from the child’s point of view since it means that the child’s placement will be determined, not by the terms of the commercial contract, but rather in accordance with the child’s own “best interest.”

  • “Distinguishing Wrongful From Rightful’ Life,” 6 Jo. of Contemporary Health Law and Policy 59-80 (1990)

This paper argues that the tort of “wrongful life” should be recognized.  The particular focus is on arguments that conclude that claims of wrongful life are somehow self-contradictory or incoherent.  I argue that they are neither.

Melinda A. Roberts — Presentations, Talks, Comments

  • “The Asymmetry.”  Invited lecture, Institute for Futures Studies Climate Ethics and Future Generations (Stockholm, Sept. 2023).
  • “The Puzzle of the Procreative Asymmetry.”  Keynote for Buffalo University Romanell Center for Clinical Ethics and the Philosophy of Medicine Saturday Workshop (Buffalo, New York Apr. 2023)
  • McMahan’s “ ‘It Might Have Been!’: Abortion, Prenatal Injury, and What Matters in Alternative Possible Lives.”  Invited comments.  University Center for Human Values, Princeton University (Oct. 2022)
  • “What Is the Problem with Moral Philosophy?”  What Is the Point of Moral Philosophy?  Oxford Uehiro Centre for Practical Ethics.  Conference in honor of Ingmar Persson.  Organized by Julian Savulescu and Ingmar Persson (Oxford July 2022)
  • “Population, Existence and Incommensurability.”  Incommensurability Conference.  Organized by Nir Eyal and Anders Herlitz (Center for Population-Level Bioethics, Rutgers University, May 2022)
  • “Why Population Ethics Should Reject the Principle of Anonymity.”  Formal Ethics Conference Series.  Organized by Paul McNamara (Jan. 2022).  International conference (virtual)
  • “Should Social Choice Theory Abandon the Principle of Anonymity?”  Invited lecture, Uppsala University (Uppsala Nov. 12, 2021) (virtual)
  • “Anonymity and the Case of the Indefinitely Iterated Addition and Reversal.”  Workshop on Complaints, Institute for Futures Studies (Stockholm, June 2021)
  • “What Is the Right Way to Make a Wrong a Right?”  Workshop on the Nonidentity Problem.  Institute for Futures Studies (Stockholm, Feb. 2020)
  • “Does Climate Change Put Ethics on a Collision Course with Itself?”  Conference on Sustainability and Future People, Umeå University (Umeå, Sweden, Feb. 2020)
  • “Population Ethics and the Ethics of Procreation,” Population and Procreative Ethics (workshop), Princeton University.  Organized by Johann Frick and Tina Rulli (Princeton May 11-12, 2019)
  • “Does the Additional Worth-Having Existence Make Things Better? Rutgers University (Value Theory Reading Group) (New Brunswick April 11, 2019)
  • “Is Climate Ethics on a Collision Course with Itself?”  Conference on Population, Public Policy and Climate. Organized by Politics, Philosophy and Economics (New Orleans March 15-16, 2019)
  • “Nonidentity and Fertility:  When Does a Choice Create a Better Chance of Existence?”  Climate Ethics and Future Generations, Workshop on Uncertainty.  Institute for Futures Studies (Stockholm Dec. 6-7, 2018)
  • “Does the Worth-Having Existence Make Things Morally Better?”  Climate Ethics and Future Generations, Kick Off Conference, Institute for Futures Studies, Stockholm (Sept. 27-29, 2018)
  • “The Better Chance Puzzle and the Value of Existence,” Oxford Parfit Conference.  Oxford University (May 18-20, 2018) (organizer Jeff McMahan/Corpus Christie College)
  • “The Better Chance Puzzle, the Nonidentity Problem and the Value of Existence.”  Conference on the Philosophical Legacy of Derek Parfit.  Conference of the International Society for Utilitarian Studies (ISUS) Karlsruhe Institute of Technology (KIT).  Germany (July 2018)
  • “The Nonidentity Problem and the Value of Existence,” American Philosophical Association Eastern Division Meetings, Savannah, Georgia (2018)
  • “Why Are Commercial Surrogacy and Baby-Selling Wrong?” (tentative title).  Comment on Eric Chwang, “Commercial Surrogacy as Less Objectionable Baby-Selling,” University Center for Human Values, Princeton University (Decamp series) (fall 2017)
  • “Axiology, Accessibility and Nonidentity,” Conference New Work in Population Ethics, Duke Center for Law, Ethics and Public Policy (April 2017)
  • “Is a Person-Affecting Solution to the Nonidentity Problem Impossible?” Binghamton University (SPEL colloquium) (February 2017)
  • “The Nonidentity Problem,” Workshop on Deontological Stances on the Nonidentity Problem, Institute for Futures Studies (Stockholm May 2016)
  • Comment on “Why Procreators Have No Special Obligations,” Axel Gosseries and Nicholas Vrousalis, University Center for Human Values DeCamp Seminar (Princeton University Feb. 2016)
  • “The Procreative Asymmetry in Ethics and the Law,” American Philosophical Association Eastern Division Meetings (Committee on Philosophy and Law) (Washington D.C. Jan. 2016)
  • “The Neutrality Intuition,” Conference on Population Ethics (Future of Humanity Institute/Project on Population Ethics: Theory and Practice, Oxford University (Nov. 2015)
  • “The Neutrality Intuition,” Princeton University Center for Human Values Fellows Seminar (Oct. 2015)
  • “Dividing and Conquering the Nonidentity Problem,” New York University Bioethics Workshop (with David Wasserman) (May 2015)
  • “Modal Ethics”  Society for Applied Ethics, Oxford University (June 2014)
  • “Rethinking ‘Mere Addition’:  Can Adding Happy People Make Things Worse?” American Philosophical Association Pacific Division Meetings (San Diego 2014)(Comment on Larry Temkin’s Rethinking the Good)
  • “Can Procreation Impose Morally Significant Harms or Benefits on the Child?” American Philosophical Association Eastern Division Meetings (Baltimore 2014)
  • Comment on Tim Campbell, “Infinite Utility and Cain’s Paradox,” Rocky Mountain Ethics Congress/RoME V (2012)
  • Comment on Howard Nye, “Responsibility for Vulnerability and the Non-Identity Problem,” American Philosophical Association Pacific Division Meetings (San Francisco 2013)
  • “Wrongful Life and Wrongful Birth,” seminar presentation, New York University (Nov. 2011)
  • “Variabilism and the Asymmetry,” University of Tennessee, Knoxville (Oct. 2011)
  • “The Person-Affecting Approach in Ethics,” super-seminar, University of Tennessee at Knoxville (Oct. 2011)
  • “Variabilism and the Asymmetry,” Rocky Mountain Ethics Congress (RoME IV) (Aug. 2011)
  • “Procreative Reasons, Procreative Obligation and Procreative Liberty,” Dubrovnik Conference On Moral Philosophy and Value Theory (June 2011)
  • “The Two Envelope Problem:  The Man Who Knew Too Much,” faculty colloquium, University of Delaware (Apr. 2011)
  • “The Nonidentity Problem,” student seminar, University of Delaware (Apr. 2011)
  • “A Variabilist Solution to the Asymmetry,” Workshop on Population Ethics, McGill University, Montreal (Mar. 2011)
  • “A Variabilist Solution to the Asymmetry,” Philamore Ethics Reading Group (Mar. 2011)
  • “Abortion and the Moral Significance of Merely Possible Persons,” Stockholm University (Dec. 2010)
  • “Abortion and the Moral Significance of Merely Possible Persons,” University of Copenhagen (Nov. 2010)
  • “The Asymmetry and Genetic Enhancement,” Workshop on Justice and Reproduction, The Nordic Network for Politics and Ethics (University of Gothenburg, Nov. 2010)
  • “Causing Harm in the Multiple Agent Context,” University catholique de Louvain, International Bernheim Workshop (Oct. 2010)
  • Comment on Saul Smilansky’s “Should We Be Sorry We Exist?” Rocky Mountain Ethics Congress (RoME III) (Aug. 2010)
  • “Does the Moral Status of Merely Possible Persons Imply that Early Abortion Is Wrong,” poster presentation, Rocky Mountain Ethics Congress (RoME III) (Aug. 2010)
  • “Does the Moral Status of Merely Possible Persons Imply that Early Abortion Is Wrong?” Society for Applied Philosophy Annual Conference (St. Anne’s College, Oxford, July 2010)
  • Comment on John Broome, “Climate Change:  How Bad Is the Chance of Catastrophe?”  DeCamp Seminar (University Center for Human Values, Princeton, Mar. 2010)
  • “An Asymmetry in the Ethics of Procreation:  Can It Be Permissible Not to Bring the Happy Child into Existence Yet Obligatory to Leave the Miserable Child Out of Existence?,” Conference on What Do We Owe to Future Persons, Cluster of Excellence/The Formation of Normative Orders, Goethe University (Frankfurt, Feb. 2010)
  • Comment on Dillard, Harman, Kamm and McMahan, “Procreation, Abortion and Harm,” Committee on Philosophy and Law, American Philosophical Association Eastern Division Meetings (Dec. 2009)
  • “Does the Moral Status of Merely Possible Persons Imply that Early Abortion Is Wrong?” New Jersey Regional Philosophical Association (Montclair State University, Nov. 2009)
  • “Counting the Costs Before They’re Hatched:  Climate Change, the Nonidentity Problem and the Moral Significance of Merely Possible Persons,” Conference on the Ethics of Climate Change:  Intergenerational Justice and the Global Challenge, University of Delaware Department of Philosophy and the American Philosophical Association (Newark, Del., Oct. 2009)
  • “Do Principles of Justice Extend to Merely Possible Persons?” Conference, Extensions of Justice, The Hebrew University of Jerusalem (Mount Scopus, June 2009)
  • Comment on Holly Smith, “Error and Uncertainty in Moral Decision-Making,” Felician Ethics Conference (Apr. 2009)
  • “Abortion and the Moral Significance of Merely Possible Persons,” University of Delaware at Newark (Nov. 2008)
  • Comment on Rivka Weinberg, “Existence:  Who Needs It?” University Center for Human Values, Princeton University (Nov. 2008)
  • “The Nonidentity Problem and the Two Envelope Problem,” University of California at Riverside (Feb. 2008)
  • Climate Change and the Problem of Collective Harm, comment on Andrew Light, Society for Applied Philosophy, Princeton Theological Institute (Oct. 2007)
  • Comment on Larry Temkin, Equality and Health Care, University Center for Human Values, Princeton University (Sept. 2006)
  • “When Do We Harm Persons by Causing Them to Exist?  Expected Value, Betterness and the Slave Child Case,” University Center for Human Values Decamp Seminar (Princeton, Oct. 2006)
  • Supernumerary Pregnancy and Harm to Persons, Center for Bioethics, University of Pennsylvania (Hart Lecture, June 2006)
  • “Assisted Reproductive Technologies and Harm to Offspring,” The American Society of Law, Medicine & Ethics 28th Annual Conference for Health Law Teachers (Newark, June 2004)
  • Comment on Noam J. Zohar, “Divine Representations and the Value of Embryos:  God’s Image, God’s Name and the Status of Human Non-Persons,” Center for Judaic Studies and University Center for Human Values (Princeton, 2004)
  • Comment on David Wasserman, “Is Every Birth Wrongful?  Is Any Birth Required?”  University Center for Human Values (Princeton, 2004)
  • “The New Reproduction Technologies and the Limits and Structure of Constitutional Privacy,” American Philosophical Association — Pacific Division Meetings (San Francisco, Mar. 2003)
  • “The Structure of Constitutional Privacy:  The ‘Right’ To Be Left Alone As a Hierarchy of Critical Privacy Interests,” American Society for Value Inquiry (Milwaukee, Apr. 2002)
  • Comment on Adrienne Asch, Selling of Human Ova, University Center for Human Values (Princeton, 2002)
  • “Person-Based Consequentialism and the Equality Problem,” American Philosophical Association — University of Delaware Ethics in the Twenty-First Century (Newark, Delaware, Nov. 2001)
  • “Am I As Good As You Are?  Two Forms of Consequentialism and Two Approaches to the Equality Problem,” American Philosophical Association — Pacific Division Meetings (Oakland, April 2001)
  • “Cloning and Harming,” American Philosophical Association — Pacific Division Meetings (Berkeley, Apr. 1999)
  • “Is the Person-Affecting Intuition Inconsistent?” American Philosophical Association — Pacific Division Meetings (Berkeley, Apr. 1997)