• Necessity in Self-Defense and War
    Philosophy and Public Affairs 40 (1): 3-44. 2012.
    It is generally agreed that using lethal or otherwise serious force in self-defense is justified only when three conditions are satisfied: first, there are some grounds for the defender to give priority to his own interests over those of the attacker (whether because the attacker has lost the protection of his right to life, for example, or because of the defender’s prerogative to prefer himself to others); second, the harm used is proportionate to the threat thereby averted; third, the harm is …Read more
  • Risky Killing and the Ethics of War
    Ethics 126 (1): 91-117. 2015.
    Killing civilians is worse than killing soldiers. Although this principle is widely affirmed, recent military practice and contemporary just war theory have undermined it. This article argues that killing an innocent person is worse the likelier it was, when you acted, that he would be innocent: riskier killings are worse than less risky killings. In war, killing innocent civilians is almost always riskier than killing innocent soldiers. So killing innocent civilians is worse than killing innoce…Read more
  • Sparing Civilians
    Oxford University Press UK. 2015.
    Killing civilians is worse than killing soldiers. If any moral principle commands near universal assent, this one does. Few moral principles have been more widely and more viscerally affirmed. And yet, in recent years it has faced a rising tide of dissent. Political and military leaders seeking to slip the constraints of the laws of war have cavilled and qualified. Their complaints have been unwittingly aided by philosophers who, rebuilding just war theory from its foundations, have concluded th…Read more
  • In dubious battle: uncertainty and the ethics of killing
    Philosophical Studies 175 (4): 859-883. 2018.
    How should deontologists concerned with the ethics of killing apply their moral theory when we don’t know all the facts relevant to the permissibility of our action? Though the stakes couldn’t be higher, and uncertainty is endemic where killing is concerned, few deontologists have an answer to this question. In this paper I canvass two possibilities: that we should apply a threshold standard, equivalent to the ‘beyond a reasonable doubt’ standard applied for criminal punishment; and that we shou…Read more
  • Deontologists have long been upbraided for lacking an account of justified decision- making under risk and uncertainty. One response is to develop a deontological decision theory—a set of necessary and sufficient conditions for an act’s being permissible given an agent’s imperfect information. In this article, I show that deontologists can make more use of regular decision theory than some might have thought, but that we must adapt decision theory to accommodate agent- centered options—permissio…Read more
  • Limited Aggregation and Risk
    Philosophy and Public Affairs 46 (2): 117-159. 2018.
    Many of us believe (1) Saving a life is more important than averting any number of headaches. But what about risky cases? Surely: (2) In a single choice, if the risk of death is low enough, and the number of headaches at stake high enough, one should avert the headaches rather than avert the risk of death. And yet, if we will face enough iterations of cases like that in (2), in the long run some of those small risks of serious harms will surely eventuate. And yet: (3) Isn't it still permissible …Read more