Paul, OK, I'll give you that one on pepper spray.
But after some more thought I'm not sure I really can accept that definition of violence anyway. It implies that the following things are inherently violent:
Government: legislation is the will, the executive branch carries it out, the judicial branch imposes its own will.
Public education, as it's required by law; also the teachers have a high degree of authority to make rules and punish transgressions.
Parenting: any standards of behavior that you hold the child to, and the discipline to support it.
A doctor's order.
A locked door: imposes your will on others that they do not enter the room.
Clothing: imposing your will that others not see your nakedness.
Self-discipline: telling myself I need to get off the couch and exercise, or stopping myself from ordering dessert, is an act of violence by this definition.
Social norms, ethics and morality: all of these impose the will of a culture upon the individual.
So I don't think I'll go with that one.
I think a definition of violence has to consider the concept of (not necessarily physical) harm. But a fired shot that misses its target and does no harm is still violent. A tornado that touches down in a junkyard, tosses stuff around that nobody cares about, and then departs without hurting any living beings or valuable property, is still violent. A swear word yelled suddenly inside a car, which the other drivers don't hear, is still violent. Falling down the stairs or sliding your car on a patch of ice and hitting a tree have no harmful intent but are still violent. Meanwhile, such things as poison, illness, and negative thinking cause harm, but are not necessarily violent...
And of course there's a difference between pain and damage (as evidenced by the pepper spray, or nikkyo).