Rights and Evidence

Some philosophers endorse a fact-relative account of moral rights against harm. According to this view, if B’s ϕ‎-ing would contravene A’s right not to be harmed if B had access to all the facts, then B contravenes A’s right by ϕ‎-ing regardless of her epistemic position. Chapter 6 argues that moral rights against harm are not fact-relative, but must rather be sensitive, to a certain extent, to the evidence that duty-bearers can reasonably be expected to possess. The chapter argues that this conception of moral rights against harm has important implications for liability to defensive harm. In particular, people who pose fact-relative wrongful harm are not always liable to defensive harm, since such people may not threaten anyone’s moral rights via their actions.

Necessity

Chapter 5 develops and defends an original account of the necessity constraint on the use of defensive force. The chapter argues that the necessity condition is grounded in the right to be rescued from harm when this rescue can be provided at reasonable cost. The chapter argues that even wrongful attackers have the right to be rescued from serious harm when others can do so at reasonable cost, and this right explains why there is a necessity condition on the permissible use of defensive force. The chapter also offers criticisms of competing conceptions of the necessity condition, as well as offering a particular view regarding the relationship between necessity and liability.

Proportionality

Chapter 4 develops and defends an original conception of proportionality in defensive force: the stringency principle. On this view, the degree of force to which a wrongful attacker renders himself liable is determined by the stringency of the right that the attacker threatens to violate. The more stringent the right that is threatened, the greater the degree of force to which the wrongful attacker is liable. The chapter also provides a critique of an influential alternative view, one that makes an attacker’s degree of liability depend, in part, on the attacker’s degree of moral responsibility for posing a wrongful threat.

Agent-Relative Prerogatives

Chapter 3 defends the view that we each possess a limited agent-relative prerogative to impose harm on people who are not liable to this harm in defence of things over which we have rightful claims. The chapter argues that this prerogative is needed to satisfactorily explain cases where someone who is not liable to defensive harm threatens an innocent person, for example, cases involving Nonresponsible Threats or Justified Attackers. The chapter also argues that the agent-relative prerogative to defensively harm nonliable persons is constrained by a particular version of the means principle. The chapter concludes by addressing a number of potential objections.

Liability

Chapter 2 develops and defends an original account of liability to defensive harm: the moral status account. On this view, a person renders himself liable to defensive harm when the evidence-relative permissibility of his act depends on the assumption that others lack certain moral rights that they in fact possess, and his act threatens, or reasonably appears to threaten, those rights. The chapter also provides criticisms of competing accounts of liability, in particular, the moral responsibility account influentially developed by Jeff McMahan, among others. The chapter concludes by addressing a number of objections that might be pressed against the moral status account.

The Means Principle

Chapter 7 develops and defends a novel conception of the means principle. The chapter argues that there is an absolute prohibition on the harmful use of another person’s body or other rightful property, unless the person who is harmed is duty bound to permit this use, or has otherwise waived their claims against such use. He argues that this principle does not focus on an agent’s intentions, but rather only on whether achieving the outcome that ostensibly justifies an agent’s act requires the use of another person’s body or rightful property. The chapter argues that this conception of the means principle is superior to competing principles in the literature, and it outlines some of the implications for the morality of defensive force.

Introduction

Chapter 1 provides an overview of the book’s main arguments and ideas, and situates the morality of defensive force in the wider literature. The chapter contains a discussion of the book’s scope and method. The chapter also sets out one of the main themes of the book; that we cannot understand the morality of defensive force until we ask and answer deeper questions about how the use of defensive force fits with a more general account of justice and moral rights. By closely studying the morality of defensive force, the chapter concludes, we also reach a deeper understanding of the way moral rights work, and their role in securing just relations between persons.