When Does Action Become Aggression?

A few discussions recently have got me thinking about when physical force may be justifiably used in response to the actions of others. There’s little controversy around using physical force to defending oneself when being physically attacked. Even most pacifists (in my experience) acknowledge that not using physical force even in those instances is a personal choice, not an ethical statement.

I consider the libertarian non-aggression principle to be quite useful most of the time in determining justified action and reaction utilizing physical force. Let me begin by defining my terms.

Physical force is the application of energy in action or movement. Examples: walking around the block; hugging a loved one; picking up or moving stuff around.

Violence is physical force applied in a destructive or potentially destructive way. Examples: punching somebody; throwing a glass against the wall; breaking an object apart.

Aggression is the initiation of physical force or violence against another person or their property without their permission. Examples: hugging someone without their permission; punching somebody without their permission; throwing somebody else’s glass against the wall without the permission of either the glass or wall owners; taking, handling, or breaking somebody else’s property without their permission.

The libertarian non-aggression principle states that a person is not justified in using aggression against other people or their property. It’s really quite unremarkable, but has enormous implications. With this principle, we can categorize most actions as either justified, or not. Here are two examples: punching a boxing opponent is justified, punching a stranger is not; moving my friend’s sofa to his new apartment is justified, moving a stranger’s sofa to my new apartment is not.

Libertarians love analyzing which actions on the fringe of human behavior constitute aggression, and which do not. The following is an example of just such analysis.

At what point should an action be considered aggression, of which it would be justified in responding with physical force or violence? Most obvious forms of uninvited physical force or violence should be considered aggression. I’ve given some examples of those. Other examples are different types of theft, battery, kidnap, rape, and murder.

I posit that trespassing, the act of entering another person’s property, is not always aggression. Sometimes it is, such as when the owner is unsure of a trespasser’s intent. Is the trespasser lost, or does he plan on hurting or robbing me or my property? It’s an unknown, and so treating it as aggression or probable aggression is not unreasonable. However, I believe there are cases where classifying a trespass as aggression is not reasonable.

Here’s one such case: a transient walking through a golf course. In this case, the transient is merely passing through. He’s not damaging or displacing the golf course in any quantifiable way. I would consider any use of physical force or violence against his person or property to be unjustified, and thus an act of aggression in and of itself. He would thus be justified in using physical force or violence in self-defense.

No, he does not have permission by the golf course owner, and yes his passing through the golf course is technically a trespass. However, it is not a trespass in any meaningful way, certainly not to the extent needed to justify the use of physical force or violence against him. What if he’s been approached once before and asked not to pass through? What if he’s been approached multiple times in the past and asked not to pass through? I still consider the trespass benign and all that entails.

At this point, the only recourse the golf course owner has is in better security. If he doesn’t want transients passing through, he should build a fence.

I think the logic used in this analysis can be applied to all sorts of situations. The relevant key in determining when the solution is physical force or violence, or when the solution is better security is the concept of quantifiable damage. Does the action produce or will it probably produce quantifiable damage? In the case of a transient passthrough, the answer seems to me to be negative.

What about a case where someone picks up and looks at someone else’s property without permission? It seems the answer is negative as well. What about a case where someone decides to squat in an unoccupied vacation home? It seems the answer is affirmative to me, as this action typically requires breaking before entering, displacement of property inside, and the threat of damage to property and/or the owners once they arrive.

Benjamin Franklin said, “An ounce of prevention is worth a pound of cure.” I consider that apropos on the question of how to prevent unwanted albeit non-aggressive actions by others as it concerns our property. I predict that in a totally free society, security will be a higher expense on our personal financial statements than will be reactionary force or violence. And without a central authority either monopolizing or subsidizing the use of violence, property norms will develop in such a way as to minimize these expenses.

Save as PDFPrint
Liked it? Support this contributor on Patreon!
Skyler J. Collins (Editor)

Written by 


Notify of
Most Voted
Newest Oldest
Inline Feedbacks
View all comments
Mark A Rivera
Mark A Rivera
3 years ago

I’ve always wondered about “pre-emptive strikes”? When does the risk of violence justify active and violent self-defense? For example, a large man is making threatening jestures at you and your family, and it appears eminent that he will strike you. If you wait for him to make the “first move”, you will not be able to defend yourself or your family thereafter. Is a pre-emptive strike, the first to initiate physical violence, justified?