The non-aggression principle states that it is immoral to initiate the use of force against people or property (in the context of property rights, people are their own property, and thus aggression can be thought of as against property, period). Defense is allowed. For instance, if Person A punches Person B in the face for no reason, then Person A is a criminal for initiating the use of force, but Person B is within their rights to defend themselves with force from Person A. In this article I explore some logical properties of non-aggression.

The Definition of Non-Aggression

First, let us clarify what the non-aggression principle is. The non-aggression principle states that it is immoral to initiate the use of force against someone’s property. If you believe in the non-aggression principle, you believe it is immoral to start fights with people, but not (necessarily) to defend yourself from someone who is attacking you. If you do happen to believe that the use of force even for defense is immoral (pacifism), that’s consistent with, but not a part of, the non-aggression principle. To be a pacifist you must be non-aggressive, but to be non-aggressive you don’t have to be a pacifist. (I believe that pacifism, defined here as anti-force under any circumstances, is unworkable, since it gives an enormous incentive to criminals since they will have so many defenseless people to prey on, and thus criminals will proliferate, defeating any attempts to create a pacifist world.)

Here are some examples. Defending yourself is not initiating the use of force, and does not violate the non-aggression principle. Employing violence against someone who has always been non-violent does violate the non-aggression principle. Putting up a fence around your property does not violate the non-aggression principle. Tearing down somebody else’s fence because you don’t like how it looks does violate the non-aggression principle. Helping to defend your friends from a violent aggressor does not violate the non-aggression principle, so long as your friends want your help. Attacking a stranger and their friends because you enjoy the feeling of their faces on your first does violate the non-aggression principle.

Non-Aggression and Peace

Non-aggression is necessary for peace. If any one person doesn’t live by the non-aggression principle, then new fights will break out every time this person initiates the use of force, and therefore peace does not exist. Non-aggression is also sufficient for peace. If everyone actually lived by the non-aggression principle (an unlikely scenario), peace would soon follow. That is because force would only be used as defense, and thus old fights would quickly come to an end, and new fights would not start. No violent exchanges would occur at all in society—the definition of peace. Non-aggression is therefore both necessary and sufficient for peace.

Non-Aggression and Win/Win, Win/Lose Exchanges

When Person A initiates the use of force against Person B, except in rare cases, Person A wins, and Person B loses. But when Person A and Person B participate in a voluntary exchange, except in rare cases, they both win. Since non-aggression is biased in favor of voluntary win/win exchanges, it seems appealing from a utilitarian point-of-view (which aims to maximize the good of all), except for those edge cases where initiating the use of force may be win/win. These hypothetical cases where aggression is win/win, which may or may not exist, are exactly the cases that statists use to argue in favor of aggression. However, it should be obvious to you that whenever you are the one being aggressed against, you are losing, because for it to constitute aggression, you must have determined, using your own information and mental effort, that this particular exchange is not in your interests. You may consider the possiblity that you are wrong about what your interests are, but your alternative is to trust someone else’s conclusions about your interests above your own, which is a contradiction, because you would have to trust your own conclusions about their conclusions, after having just admitted that your own conclusions are untrustworthy. Therefore, you have no choice but to trust your own conclusions about what your interests are. Therefore, it is impossible to perceive a situation where you are the one being aggressed against as anything other than not in your interests (if you are rational). Further, whatever you conclude your own interests are, say X, then your interests are X. (These are what I like to call “high-level” interests, which are beliefs that you arrive at, and are distinguished from “low-level” interests which are pleasure and (being averse to) pain. Also, don’t confuse your gene’s “interests” with your own interests. Your interests are calculated in your brain. Your genes’s “interests” are increased frequency in the gene pool, and this may or may not coincide with your interests, which may include, say, not wanting to have children.) By concluding that such an exchange is not in your interests, then it is not in your interests. At some later point in time, you may gain as a consequence of the exchange, but that does not change the fact that you have lost by being aggressed against. The utilitarian argues that a net-positive outcome that eventually results from initiating force is worth criminal action in the present, but that doesn’t change the fact that initiating force in the present is criminal in the present.

Non-Aggression and Rationality

Suppose that you are the one doing the aggressing. Although it can never be rational to accept force being initiated against yourself, it can be rational to initiate force against others. Perhaps you believe an exchange will be win/win if you initiate force, or perhaps even win/lose, where you are the one winning. It should be obvious that although it might be rational to do this, it can never be moral. The person you are aggressing against is either convinced you are a criminal, or they are brainwashed or irrational in some other sense. Initiating force against them, even if you passionately believe you are doing them good, they will passionately believe otherwise, and rightly regard you as being a criminal (if they are rational).

Further, if you initiate force, it is more likely to be win/lose than win/win, for the simple empirical reason that people do actually have a pretty good idea what’s good for themselves, since they have information about their lives that you never will. In practice, the reason why Person A initiates force against Person B is obviously because it is in Person A’s interests, irrespective of the interests of Person B.

Conclusion

The non-aggression principle states that it is immoral to initiate the use of force. We have demonstrated that non-aggression is the principle of peace, that aggression is never in the interests of the person being aggressed against, and although aggression can sometimes be rational, it can never be moral.