•  61
    Humanity stands at a precipice. Our species could survive for millions of generations — enough time to end disease, poverty, and injustice; to reach new heights of flourishing. But this vast future is at risk. With the advent of nuclear weapons, humanity entered a new age, gaining the power to destroy ourselves, without the wisdom to ensure we won’t. Since then, these dangers have only multiplied, from climate change to engineered pandemics and unaligned artificial intelligence. If we do not ac…Read more
  •  1075
    The Repugnant Conclusion served an important purpose in catalyzing and inspiring the pioneering stage of population ethics research. We believe, however, that the Repugnant Conclusion now receives too much focus. Avoiding the Repugnant Conclusion should no longer be the central goal driving population ethics research, despite its importance to the fundamental accomplishments of the existing literature.
  • It is often said that there are three great traditions of normative ethics: consequentialism, deontology and virtue ethics. Each is based around a compelling intuition about the nature of ethics: that what is ultimately important is that we produce the best possible outcome, that ethics is a system of rules which govern our behaviour, and that ethics is about living a life that instantiates the virtues, such as honesty, compassion and loyalty. This essay is about how best to interpret consequent…Read more
  •  2
    Bubbles under the Wallpaper: Healthcare Rationing and Discrimination
    In Helga Kuhse, Udo Schüklenk & Peter Singer (eds.), Bioethics: An Anthology, 3rd Edition, Wiley. pp. 406-412. 2016.
    It is common to allocate scarce health care resources by maximizing QALYs per dollar. This approach has been attacked by disability-rights advocates, policy-makers, and ethicists on the grounds that it unjustly discriminates against the disabled. The main complaint is that the QALY-maximizing approach implies a seemingly unsatisfactory conclusion: other things being equal, we should direct life-saving treatment to the healthy rather than the disabled. This argument pays insufficient attention to…Read more
  •  59
    Moral Uncertainty
    Oxford University Press. 2020.
    How should we make decisions when we're uncertain about what we ought, morally, to do? Decision-making in the face of fundamental moral uncertainty is underexplored terrain: MacAskill, Bykvist, and Ord argue that there are distinctive norms by which it is governed, and which depend on the nature of one's moral beliefs.
  •  124
    Statistical Normalization Methods in Interpersonal and Intertheoretic Comparisons
    with William MacAskill and Owen Cotton-Barratt
    Journal of Philosophy 117 (2): 61-95. 2020.
    A major problem for interpersonal aggregation is how to compare utility across individuals; a major problem for decision-making under normative uncertainty is the formally analogous problem of how to compare choice-worthiness across theories. We introduce and study a class of methods, which we call statistical normalization methods, for making interpersonal comparisons of utility and intertheoretic comparisons of choice-worthiness. We argue against the statistical normalization methods that have…Read more
  •  53
    The many forms of hypercomputation
    Journal of Applied Mathematics and Computation 178 142-153
    This paper surveys a wide range of proposed hypermachines, examining the resources that they require and the capabilities that they possess. 2005 Elsevier Inc. All rights reserved
  •  1478
    Making Fair Choices on the Path to Universal Health Coverage
    with Ole Frithjof Norheim, Trygve Ottersen, Bona Chitah, Richard Cookson, Norman Daniels, Nir Eyal, Walter Flores, Axel Gosseries, Daniel Hausman, Samia Hurst, Lydia Kapiriri, Shlomi Segall, Frehiwot Defaye, Alex Voorhoeve, and Alicia Yamin
    World Health Organisation. 2014.
    This report by the WHO Consultative Group on Equity and Universal Health Coverage addresses how countries can make fair progress towards the goal of universal coverage. It explains the relevant tradeoffs between different desirable ends and offers guidance on how to make these tradeoffs.
  •  75
    Moral Uncertainty About Population Axiology
    Journal of Ethics and Social Philosophy 12 (2): 135-167. 2017.
    Given the deep disagreement surrounding population axiology, one should remain uncertain about which theory is best. However, this uncertainty need not leave one neutral about which acts are better or worse. We show that, as the number of lives at stake grows, the Expected Moral Value approach to axiological uncertainty systematically pushes one toward choosing the option preferred by the Total View and critical-level views, even if one’s credence in those theories is low.
  •  1041
    Cómo tomar decisiones justas en el camino hacia la cobertura universal de salud
    with Ole Frithjof Norheim, Trygve Ottersen, Bona Chitah, Richard Cookson, Norman Daniels, Frehiwot Defaye, Nir Eyal, Walter Flores, Axel Gosseries, Daniel Hausman, Samia Hurst, Lydia Kapiriri, Shlomi Segall, Gita Sen, Alex Voorhoeve, Tessa T. T. Edejer, Andreas Reis, Ritu Sadana, Carla Saenz, Alicia Yamin, and Daniel Wikler
    Pan-American Health Organization (PAHO). 2015.
    La cobertura universal de salud está en el centro de la acción actual para fortalecer los sistemas de salud y mejorar el nivel y la distribución de la salud y los servicios de salud. Este documento es el informe fi nal del Grupo Consultivo de la OMS sobre la Equidad y Cobertura Universal de Salud. Aquí se abordan los temas clave de la justicia (fairness) y la equidad que surgen en el camino hacia la cobertura universal de salud. Por lo tanto, el informe es pertinente para cada agente que infl uy…Read more
  •  281
    Suppose that we develop a medically safe and affordable means of enhancing human intelligence. For concreteness, we shall assume that the technology is genetic engineering (either somatic or germ line), although the argument we will present does not depend on the technological implementation. For simplicity, we shall speak of enhancing “intelligence” or “cognitive capacity,” but we do not presuppose that intelligence is best conceived of as a unitary attribute. Our considerations could be applie…Read more
  •  1116
    Moral uncertainty about population ethics
    Journal of Ethics and Social Philosophy. forthcoming.
    Given the deep disagreement surrounding population axiology, one should remain uncertain about which theory is best. However, this uncertainty need not leave one neutral about which acts are better or worse. We show that as the number of lives at stake grows, the Expected Moral Value approach to axiological uncertainty systematically pushes one towards choosing the option preferred by the Total and Critical Level views, even if one’s credence in those theories is low.
  •  1285
    Faire Des Choix Justes Pour Une Couverture Sanitaire Universelle
    with Ole Frithjof Norheim, Trygve Ottersen, Bona Chitah, Richard Cookson, Norman Daniels, Frehiwot Defaye, Nir Eyal, Walter Flores, Axel Gosseries, Daniel Hausman, Samia Hurst, Lydia Kapiriri, Shlomi Segall, Gita Sen, Alex Voorhoeve, Daniel Wikler, Alicia Yamin, Tessa T. T. Edejer, Andreas Reis, Ritu Sadana, and Carla Saenz
    World Health Organization. 2015.
    This report from the WHO Consultative Group on Equity and Universal Health Coverage offers advice on how to make progress fairly towards universal health coverage.
  •  302
    Why Maximize Expected Choice‐Worthiness?1
    Noûs 54 (2): 327-353. 2018.
    This paper argues in favor of a particular account of decision‐making under normative uncertainty: that, when it is possible to do so, one should maximize expected choice‐worthiness. Though this position has been often suggested in the literature and is often taken to be the ‘default’ view, it has so far received little in the way of positive argument in its favor. After dealing with some preliminaries and giving the basic motivation for taking normative uncertainty into account in our decision‐…Read more
  •  8
    The scourge: Moral implications of natural embryo loss (plaga. Moralne konsekwencje naturalnej utraty embrionu)
    Archeus. Studia Z Bioetyki I Antropologii Filozoficznej 10 63-79. 2009.
  •  36
    Ω in number theory
    In C. S. Calude (ed.), Randomness and Complexity, from Leibniz to Chaitin, World Scientific. pp. 161-173. 2007.
    We present a new method for expressing Chaitin’s random real, Ω, through Diophantine equations. Where Chaitin’s method causes a particular quantity to express the bits of Ω by fluctuating between finite and infinite values, in our method this quantity is always finite and the bits of Ω are expressed in its fluctuations between odd and even values, allowing for some interesting developments. We then use exponential Diophantine equations to simplify this result and finally show how both methods can also…Read more
  •  213
    Consequentialism and Decision Procedures
    Dissertation, University of Oxford. 2005.
    Consequentialism is often charged with being self-defeating, for if a person attempts to apply it, she may quite predictably produce worse outcomes than if she applied some other moral theory. Many consequentialists have replied that this criticism rests on a false assumption, confusing consequentialism’s criterion of the rightness of an act with its position on decision procedures. Consequentialism, on this view, does not dictate that we should be always calculating which of the available acts …Read more
  •  37
    Using biased coins as oracles
    with Tien D. Kieu
    International Journal of Unconventional Computing 5 253-265. 2009.
    While it is well known that a Turing machine equipped with the ability to flip a fair coin cannot compute more than a standard Turing machine, we show that this is not true for a biased coin. Indeed, any oracle set X may be coded as a probability pX such that if a Turing machine is given a coin which lands heads with probability pX it can compute any function recursive in X with arbitrarily high probability. We also show how the assumption of a non-recursive bias can be weakened by using a..
  •  82
    Moral Trade
    Ethics 126 (1): 118-138. 2015.
    If people have different resources, tastes, or needs, they may be able to exchange goods or services such that they each feel they have been made better off. This is trade. If people have different moral views, then there is another type of trade that is possible: they can exchange goods or services such that both parties feel that the world is a better place or that their moral obligations are better satisfied. We can call this moral trade. I introduce the idea of moral trade and explore severa…Read more
  •  79
    Many of the commentaries have made similar points regarding the nature of full moral status, so I shall begin by addressing these together. They argue that my representation of the Claim is stronger than many proponents of full moral status would accept (Ord 2008). Robert Card (2008) says that I assume that it is equally bad to lose human life at all stages. Russell DiSilvestro (2008) says that I assume a flawed principle that he calls (M). Marianne Burda (2008) says that I assume that life must…Read more
  •  60
    – We present a new paradigm extending the Iterated Prisoner's Dilemma to multiple players. Our model is unique in granting players information about past interactions between all pairs of players – allowing for much more sophisticated social behaviour. We provide an overview of preliminary results and discuss the implications in terms of the evolutionary dynamics of strategies
  •  40
    On the existence of a new family of diophantine equations for Ω
    Fundamenta Informaticae 56 273-284. 2003.
    We show how to determine the k-th bit of Chaitin’s algorithmically random real number Ω by solving k instances of the halting problem. From this we then reduce the problem of determining the k-th bit of Ω to determining whether a certain Diophantine equation with two parameters, k and N , has solutions for an odd or an even number of values of N . We also demonstrate two further examples of Ω in number theory: an exponential Diophantine equation with a parameter k which has an odd number of solu…Read more
  •  155
    The diagonal method and hypercomputation
    with Tien D. Kieu
    British Journal for the Philosophy of Science 56 (1): 147-156. 2005.
    The diagonal method is often used to show that Turing machines cannot solve their own halting problem. There have been several recent attempts to show that this method also exposes either contradiction or arbitrariness in other theoretical models of computation which claim to be able to solve the halting problem for Turing machines. We show that such arguments are flawed—a contradiction only occurs if a type of machine can compute its own diagonal function. We then demonstrate why such a situati…Read more
  •  89
    Hypercomputation: Computing more than the Turing machine
    Dissertation, University of Melbourne. 2002.
    In this report I provide an introduction to the burgeoning field of hypercomputation – the study of machines that can compute more than Turing machines. I take an extensive survey of many of the key concepts in the field, tying together the disparate ideas and presenting them in a structure which allows comparisons of the many approaches and results. To this I add several new results and draw out some interesting consequences of hypercomputation for several different disciplines.
  •  63
    Some risks have extremely high stakes. For example, a worldwide pandemic or asteroid impact could potentially kill more than a billion people. Comfortingly, scientific calculations often put very low probabilities on the occurrence of such catastrophes. In this paper, we argue that there are important new methodological problems which arise when assessing global catastrophic risks and we focus on a problem regarding probability estimation. When an expert provides a calculation of the probability…Read more
  •  99
    A New Counterexample to Prioritarianism
    Utilitas 27 (3): 298-302. 2015.
    Prioritarianism is the moral view that a fixed improvement in someone's well-being matters more the worse off they are. Its supporters argue that it best captures our intuitions about unequal distributions of well-being. I show that prioritarianism sometimes recommends acts that will make things more unequal while simultaneously lowering the total well-being and making things worse for everyone ex ante. Intuitively, there is little to recommend such acts and I take this to be a serious counterex…Read more
  •  270
    The scourge: Moral implications of natural embryo loss
    American Journal of Bioethics 8 (7). 2008.
    It is often claimed that from the moment of conception embryos have the same moral status as adult humans. This claim plays a central role in many arguments against abortion, in vitro fertilization, and stem cell research. In what follows, I show that this claim leads directly to an unexpected and unwelcome conclusion: that natural embryo loss is one of the greatest problems of our time and that we must do almost everything in our power to prevent it. I examine the responses available to those w…Read more
  •  239
    Over the last few decades, there has been an increasing interest in global consequentialism. Where act-consequentialism assesses acts in terms of their consequences, global consequentialism goes much further, assessing acts, rules, motives — and everything else — in terms of the relevant consequences. Compared to act-consequentialism it offers a number of advantages: it is more expressive, it is a simpler theory, and it captures some of the benefits of ruleconsequentialism without the correspond…Read more