Non-aggression principle

The non-aggression principle (NAP) is a concept in which "aggression"—defined as initiating or threatening any forceful interference with an individual, their property or their agreements (contracts)—is illegitimate and should be prohibited. Interpretations of the NAP vary, particularly concerning issues like intellectual property, force, and abortion.

Like the Golden Rule, the Non-Aggression Principle follows an ethics of reciprocity, in the sense that whether a person's action is permissible, depends upon the preceding actions of others.

The non-aggression principle is considered by some to be a, or even the, defining principle of libertarianism. It is a common principle among right-libertarians of both minarchist and anarcho-capitalist beliefs.