The non-aggression principle or NAP (sometimes the zero aggression principle) is a simple concept that helps identify and avoid unethical behavior in ourselves and others. The principle states that it is unethical and unjust to initiate coercion, physical force, threats, or fraud against other people.
“Initiation” is the key word; since there’s obviously no magical guarantee that all people will adhere to this principle, you are perfectly justified to respond as necessary to stop aggression if it’s used against you. NAP is not the same as pacifism; neither is it a strict, be-all-end-all definition of what is unethical.
The principle may sound rather obvious at its face, but once you really start to look at things, you’ll start to notice just how much modern society is based on aggression, from government (see “The State is Institutionalized Violence”) to parenting (through spanking and threats rather than understanding, explaining, and reasoning) and everywhere in between.
If you accept the non-aggression principle, then you’re already on your way down the road to a voluntary, stateless lifestyle. Welcome! If you’re interested in learning more, here are a couple of helpful videos:
Animated and easy to understand even if it is a little bit corny.
Voluntaryism: The Non-Aggression Principle (NAP)