(See also: Non-Aggression Principle.)
[bk]
Anyone who is still unhappy with this use of the term "coercion" can simply eliminate the word from this discussion and substitute for it "physical violence or the threat thereof," with the only loss being in literary style rather than in the substance of the argument. What anarchism proposes to do, then, is to abolish the state, that is, to abolish the regularized institution of aggressive coercion.
Murray N. Rothbard, "Society without a State"
[rothbard]
If we consider that each person owns his own body and can acquire ownership of other things by creating them, or by having ownership transferred to him by another owner, it becomes at least formally possible to define "being left alone" and its opposite, "being coerced". Someone who forcibly prevents me from using my property as I want, when I am not using it to violate his right to use his property, is coercing me. A man who prevents me from taking heroin coerces me; a man who prevents me from shooting him does not.
David Friedman, The Machinery of Freedom
[friedman]