Institutio Oratoria

And there is clearly far more justification for lying when it is a question of diverting an assassin from his victim or deceiving an enemy to save our country. Consequently a practice which is at times reprehensible even in slaves, may on other occasions be praiseworthy even in a wise man. If this be granted, I can see that there will be many possible emergencies such as to justify an orator in undertaking cases of a kind which, in the absence of any honourable reason, he would have refused to touch.

In saying this I do not mean that we should be ready under any circumstances to defend our father, brother or friend when in peril (since I hold that we should be guided by stricter rules in such matters), although such contingencies may well cause us no little perplexity, when we have to decide between the rival claims of justice and natural