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Philosophy Department Publishes New Treatise on the Ethics of Self-Defense

Defining the Moral Boundaries of Force in a Free Society

The Department of Philosophy at the New Hampshire Institute of Libertarian Sciences has published a seminal new work, The Just Defense: A Systematic Theory of Defensive Ethics from First Principles. This treatise, authored by a team led by Senior Fellow Dr. Aris Thorne, represents the most rigorous and comprehensive analysis to date of the ethics of self-defense within the libertarian framework. While the non-aggression principle (NAP) clearly prohibits the initiation of force, its application in defensive scenarios is fraught with complexity. When is force proportionate? What constitutes imminent threat? What are the rights and responsibilities of bystanders? Can defensive force be delegated? This book tackles these difficult questions head-on, providing a logical structure for evaluating any defensive act.

Foundations: From Self-Ownership to the Right to Defend

The treatise begins by firmly grounding the right of self-defense in the principle of self-ownership. If an individual owns their own person, then they necessarily have the right to protect that ownership from invasion. This is not a secondary right granted by society or the state, but an inseparable corollary of self-ownership. The authors then engage in a meticulous process of defining key terms: Aggression is defined as the initiation of (or threat of initiation of) physical interference with the person or rightfully acquired property of another. Defense is action taken to halt, repel, or rectify an ongoing or imminent aggression.

A major contribution is the treatise's detailed analysis of imminence. Rejecting both the overly restrictive "about to strike" standard and the overly permissive "potential future threat" standard, the authors develop a sliding scale based on evidence of intent, capability, and concrete movement toward action. They also introduce the concept of "constructive aggression," such as a trespass that, by its nature, creates a reasonable apprehension of imminent harm (e.g., a stranger forcibly entering one's home at night).

The Calculus of Proportionality and the Duty to Retreat

The most challenging chapter deals with proportionality. The authors argue that defensive force must be objectively proportionate to the threat posed by the aggression, not to the harm already inflicted. The goal of defense is to stop the aggression, not to punish. Therefore, if a shove can be stopped by stepping back and blocking, lethal force is disproportionate. However, they firmly reject any legal "duty to retreat" from one's own property. One has the right to stand one's ground on one's own homestead. In public spaces, the treatise argues for a standard of "reasonable opportunity to retreat without increasing danger." If safe retreat is possible, it should be taken to minimize violence; if not, standing one's ground is justified.

The work also delves into the ethics of defending others (the right of other-defense), which it derives from the right of contract and association. If person A contracts with person B for protection, B's right to defend A is delegated from A's own right of self-defense. In the absence of explicit contract, the authors argue one may intervene to defend a third party if one is reasonably certain that the person being attacked wishes to be defended and that one's intervention will not escalate the situation uncontrollably. The defense of property is treated separately, with a strong argument that lethal force is almost never proportionate to defend property alone, except in extreme scenarios where the loss of property constitutes a direct threat to life (e.g., stealing the only medicine in a remote location).

Collective Defense and Resistance to Tyranny

The final section of the treatise is its most politically significant. It scales the ethics of defense from individual interactions to the collective level: resistance against a tyrannical state. The authors establish that a government that systematically violates the rights of its subjects is, by definition, a criminal gang engaged in ongoing mass aggression. The subjects, individually and collectively, therefore retain the right to defend themselves against this aggression.

The Just Defense is already being adopted as a core text in advanced philosophy courses at NHILS and is sparking intense debate in libertarian circles worldwide. It moves the discussion beyond slogan and into the realm of actionable, principled guidance for individuals and communities seeking to live freely in a dangerous world.