 It is not quite accurate to say that the state or its government has a monopoly of force, since one can justifiably use force as a citizen to defend oneself or others from an attack or assault that is not itself justified (being criminal or insane), and this requires no authorization. Still, Aquinas insistently draws a distinction between private and public use of force. Only public authority can punish or rightly engage in war, and it is reasonable for public authorities to seek a virtual monopoly on what would now be called police operations for the prevention, suppression, and detection of crime. Private persons can never rightly intend precisely to harm or kill, though they can knowingly bring about harm or death as a proportionate side-effect of intending to block an attack (3.4.1 above). Persons with public authority can, Aquinas thinks, rightly intend to kill (or injure) in the exercise of their duty to suppress the attacks of criminals, pirates, and other public or private enemies. (He does not explore those borderland or badland – “wild west” – situations where the distinction between public and private is indistinct.)