The precondition of a civilized society is the barring of physical force from
social relationships—thus establishing the principle that if men wish to deal
with one another, they may do so only by means of reason: by discussion,
persuasion and voluntary, uncoerced agreement.
The necessary consequence of man’s right to life is his right to self-defense.
In a civilized society, force may be used only in retaliation and only against
those who initiate its use.