From the early centuries through the Reformation and beyond, Christian thinkers distinguished between violence and just acts of force. Justin argued that every “honourable person” would agree that “rulers should give their decision as having followed not violence and tyranny but piety and philosophy” ( First Apology , 2). Tertullian recognized that the lex talionis was given as a restraint on violence rather than as blanket permission ( Against Marcion , 16). For Eusebius, a man who shows no allegiance to God and who is vicious may “be deemed powerful through despotic violence” but he does not have a real claim to the title “emperor” ( Speech for the Thirtieth Anniversary of Constantine’s Accession , 5). John Chrysostom is careful to point out that Israel plundered Egypt “without violence or wrong” ( Twelfth Homily on 1 Timothy ).Though Augustine sometimes speaks of war as repulsing enemy violence “with equal violence for the protection of the citizens” ( On Free Choice of the Will , 1.5), he also describes war as being “against violent resistance” ( Against Faustus 22.74).

Similar notions of violence are evident in the legal and political theorists of Western Christendom throughout the Middle Ages.

In his Summa Decretorum (1.1), Rufinus the Canonist argued that natural law permits rulers “forcible to repel violence,” and cites the Digest to show that “overcoming violence and injustice is a matter for the law of nations.” Even wild animals exhibit the first principle, since they “repel violence.” But repelling violence is not itself an act of violence; it is an act of “force.” Authority may fail to derive from God, Thomas says, if it is acquired “through violence, or simony or some other illegal method” ( Commentary on the Sentences of Peter Lombard , 2.44.2).

Wyclif warned that there was no valid right of conquest, warning that the principle that permits it inculcates “rapacious and predatory attacks against their weaker brethren.” He cites Proverbs 21:7 in support: “The violence of the wicked will sweep them away” ( Civil Lordship , 1.21). Nicholas of Cusa was summing up a medieval commonplace when he wrote that “all violence is opposed to law” ( Catholic Concordance , 3.4).Luther argued that it was no violation of the Sermon on the Mount to appeal to the law against “violence and malice” ( The Sermon on the Mount ). Grotius cited Euripides to the effect that “God hates violence” ( Right of War and Peace 1.1.10).

All citations taken from Oliver O’Donovan and Joan Lockwood O’Donovan, eds., From Irenaeus to Grotius: A Sourcebook in Christian Political Thought .