Through law and coercive force employed against those who refuse to abide by the consensus solution.
You use the term "law" quite oddly. Apparently, any act of self-defense is an act of "law", even before the Greeks and Romans had invented the subject in its roughly modern form, or before codifiers such as Hammurabi came along. For kicks, you're compounding this by equating self-defense and robbery, as both "coercive force".