This essay considers complications introduced by the Trolley Problem to the discussion of whether and when harming some for the sake of helping others would be unjustified. It first examines Guido Pincione’s arguments for the conclusion that the permissibility of a bystander turning a runaway trolley from killing five people toward killing one other person instead may undermine one moral argument for political libertarianism and against redistributive taxation, namely that we may not harm some people in order to help others to a greater degree. It then considers both the bearing on Pincione’s argument of recent objections to the permissibility of turning the trolley, as well as the soundness of the objections. Finally, the essay considers the relevance of trolley cases for developing a theory of aggression, insofar as aggression is the unjustified use of force that is either foreseen or intended.

This essay contrasts two approaches to permissible self-defensive killing. The first is the forfeiture approach; the second is the elbow room for self-defense approach. The forfeiture approach comes in many versions — not all of which make prominent use of the word “forfeiture.” However, all versions presume that the permissibility of X killing Y (when X must kill Y in order to prevent herself from being unjustly killed) depends entirely on there being some feature of Y in virtue of which Y has become liable to be killed, that is, in virtue of which Y has forfeited or lost or been stripped of his right not to be killed. Different versions of the forfeiture approach advance different claims about what feature of Y will render Y liable to being killed by X. I criticize versions of this approach offered by Thomson, Otsuka, and McMahan and argue that the shared deep error is the presumption that the permissibility of X’s action turns entirely on some feature of Y. In focusing entirely on Y, the forfeiture approach fails to take seriously X’s right of self-defense. In contrast, the elbow room for self-defense approach starts with an explication of a plausible right of self-defense and maintains that a proper explication of Y’s right not to be killed must make moral elbow room from X’s exercise of this right. Within the elbow room approach, Y’s liability to being killed is based upon X’s right of self-defense rather than the permissibility of X’s killing Y being based upon Y’s forfeiture.

This essay argues for what may be called the parity thesis: Whenever it would be morally permissible to kill a civilian in self-defense or in defense of others against that civilian's unjust acts, it would also be permissible to kill government officials, including police officers, prison officers, generals, lawmakers, and even chief executives. I argue that in realistic circumstances, violent resistance to state injustice is permissible, even and perhaps especially in reasonably just democratic regimes. When civilians see officials about to commit certain severe injustices — such as police officers engaging in excessive violence — they may sometimes act unilaterally and kill the offending officials. I consider and rebut a wide range of objections, including objections against vigilantism, objections based on state legitimacy, and objections that violence can produce bad fallout.

Libertarianism is a controversial political theory. But it is often presented as a resting upon a simple, indeed commonsense, moral principle. The libertarian “Nonaggression Principle” (NAP) prohibits aggression against the persons or property of others, and it is on this basis that the libertarian opposition to redistributive taxation, legal paternalism, and perhaps even the state itself is thought to rest. This essay critically examines the NAP and the extent to which it can provide support for libertarian political theory. It identifies two problems with existing libertarian appeals to the NAP. First, insofar as libertarians employ a moralized understanding of aggression, their principle is really about the protection of property rights rather than the prohibition of aggression. Second, the absolutist prohibition on aggression, which libertarians typically endorse and which is necessary to generate strongly libertarian conclusions, is grossly implausible. The essay concludes by setting forth a version of the NAP that does not suffer from these problems. It argues that this more moderate and defensible version of the NAP still has important libertarian implications, but that a full defense of libertarianism cannot rely upon appeals to nonaggression alone.

A good deal of contemporary moral nonconsequentialism assumes that agents have perfect knowledge about the various features and consequences of their options. This assumption is unrealistic. More often than not, moral agents can only assess with a certain degree of probability the factual circumstances that are morally relevant for their decision making. My aim in this essay is to discuss the problem of moral decisions under risk from the point of view of nonconsequentialism. Basically, I analyze how objective moral principles can be transformed into subjective, decisional prescriptions, and argue that the standard nonconsequentialist approach to moral decision making, which focuses on probability thresholds, is wrong. In accordance with the fundamental postulates of nonconsequentialism, I seek to solve the problem of risk in moral choice by proposing a theory about the marginal moral value of various options. Actions can vary along various dimensions, and each of these dimensions can offer a different moral value function. Nonconsequentialist marginalism can level the playing field with consequentialism. Whereas consequentialism can simply borrow the notion of expected utility from economics, nonconsequentialism must introduce the notion of expectational obligation to formulate a general principle of moral choice under risk. I finally suggest that further empirical work is needed to delineate the shape of various moral value functions that are critical for applying the general principle of moral decision making under risk to well-known cases.

In this essay, I defend a theory of liability to defensive force. The theory contains two elements. The first is a dual Lockean-inspired condition. The second aims to make this first condition consistent with problems arising from uncertainty. Drawing on recent work by Michael Zimmerman, I argue that the rights-based condition should be made sensitive to the evidence available to defenders.

Recent behavioral economics studies have shown that third parties compensate players in Dictator, Ultimatum, and Trust games. However, there are almost no studies about what drives third parties to compensate victims in such games. It can be argued that compensation is a form of helping; and helping behavior, in a variety of forms, has been widely researched, especially with regard to motivators. Previous work on helping behavior has focused on empathic concern as a primary driver. In sharp contrast, anger is often seen as an antisocial motivator resulting in aggression. However, other research has shown that moral outrage, anger evoked by the violation of a moral rule or a social norm, can lead to the punishment of a perpetrator, often described as altruistic or pro-social punishment. Some of the motivations for pro-social punishment, namely a concern for justice or the restoration of community values, can also be realized through victim compensation. We therefore propose the hypothesis that moral outrage leads to compensating behavior above and beyond what is predicted by empathic concern, but only when a social norm has been violated. We test this hypothesis in two studies, both of which use modified trust games in which the investor experiences a loss due either to a social norm violation or some other cause. Study 1 shows that trait moral outrage predicts third-party compensatory behavior above and beyond empathic concern, but only when a social norm is violated. To better understand the causal mechanism, Study 2 directly manipulated moral outrage, showing again that moral outrage leads to compensation, but only when a social norm is violated.

This essay undertakes two tasks: first, to describe the differing mens rea requirements for accomplice liability of both Anglo-American common law and the American Law Institute's Model Penal Code; and second, to recommend how the mens rea requirements of both of these two sources of criminal law in America should be amended so as to satisfy the goals of clarity and consistency and so as to more closely conform the criminal law to the requirements of moral blameworthiness. Three "pure models" of the mens rea requirements for complicity are distinguished, based on the three theories of liability conventionally distinguished in the general part of Anglo-American criminal law. One of these, the vicarious responsibility model, is put aside initially because of both its descriptive inaccuracy and its normative undesirability. The analysis proceeds using the other two models: that of the mens rea requirements for principal liability for completed crimes, and that of the mens rea requirements for attempt liability. Both the common law and the Model Penal Code are seen as complicated admixtures of these two models, the common law being too narrow in the scope of its threatened liability and the Model Penal Code being both too broad and too opaque in its demands for accomplice liability. The normative recommendation of the paper is to adopt the model for the mens rea of complicity that treats it as a form of principal liability, recognizing that the overbreadth of liability resulting from adoption of that model would have to be redressed by adopting a "shopkeeper's privilege" as an affirmative defense separate from any mens rea requirement.

In his famous book Just and Unjust Wars, Michael Walzer articulates a thesis he calls the “Moral Equality of Soldiers,” namely, the principle that combatants have an equal right to kill other combatants in war, regardless of the justice of the cause for which they are fighting. The Moral Equality Thesis, as I shall call it, is an essential component of traditional Just War Theory, in that it provides the basis for distinguishing the jus in bello from the jus ad bellum. It also plays a crucial role in identifying the nature of the difference between combatants and civilians. The Moral Equality Thesis has recently come under attack by scholars of Just War Theory, notably philosopher Jeff McMahan, on the grounds that killing for immoral purposes cannot be justified, and so it cannot be true that combatants all have an equal right to kill, regardless of the justice of their cause. In this essay, I defend the Moral Equality Thesis in its traditional formulation. Without it, I argue, the rule of law would not apply in war. The failure to recognize the equal right of combatants to kill in war, I suggest, creates an inconsistency between the rules of war and basic concepts in the law and morality of self-defense, an inconsistency that McMahan himself would think undesirable. I argue that McMahan’s argument applies more compellingly to armed conflict in asymmetrical warfare. Arguably, the Moral Equality Thesis does not apply in an armed conflict between combatants and unlawful combatants. In that context, the divergence from the law and morality of self-defense is less of a concern.

The ideal of public justification holds, at a minimum, that the most fundamental political and legal institutions of a society must be publicly justified to each of its members. This essay proposes and defends a new account of this ideal. The account defended construes public justification as an ideal of rational justification, one that is grounded in the moral requirement to respect the rational agency of persons. The essay distinguishes two kinds of justifying reasons that bear on politics and shows how they inform the ideal of public justification. It also decouples public justification from contractualist political morality. The result is a novel account of public justification that departs markedly from how the ideal is commonly characterized, but shows how it retains its distinctiveness as an ideal of politics.

In the last ten or fifteen years, realism has emerged as a distinct approach in political theory. Realists are skeptical about the merits of abstract theories of justice. They regard peace, order, and stability as the primary goals of politics. One of the more concrete aims of realists is to develop a realist perspective on legitimacy. I argue that realist accounts of legitimacy are unconvincing, because they do not solve what I call the “puzzle of legitimacy”: the puzzle of how some persons can have the right to rule over others, given that all persons are equals. I focus on the realist accounts of legitimacy developed by Bernard Williams and John Horton.