It is a fine line that divides a stratagem from an act of perfidy. Valerius Maximus denounces as an act of perfidy the conduct of Cnæus Domitius, who, having received the King of the Arverni as a guest under the pretence of a colloquy, sent him by sea a prisoner to Rome;[187] but it is not easy to distinguish it from the actions of Montluc or Feuquières. Vattel lays down the following doctrine on the subject: As humanity compels us to prefer the gentlest means in the prosecution of our rights, if we can master a strong place, surprise or overcome an enemy by a stratagem or a feint void of perfidy, it is better to do so than to have resort to a bloody siege or the carnage of a battle. He expressly excludes perfidy; but might not Polyænus have defended it on precisely the same humanitarian grounds as those by which Vattel justifies the more ordinary stratagems? Might not an act of perfidy equally prevent a siege or a battle? If we are justified in contending for our rights by force, it is hard to say that we may not do so by fraud; but it is still harder to distinguish the kinds and the limits of such fraud, or to say where it ceases to be lawful. And to this length did Polyænus apparently go, as we see in the cases of downright perfidy which he includes in his collection of stratagems. The Locrians swore to observe a treaty with the Sicilians so long as they trod the earth they then walked on, or carried their heads on their shoulders: the next day they threw away the heads of garlic which they had carried under their cloaks on their shoulders, and the earth they had strewn in their shoes, and began a general massacre of the Sicilians.[188] The Campanians, having agreed to surrender half their arms, cut them in half, and so virtually surrendered nothing.[189] Paches, the Athenian, says Frontinus, having promised personal safety to his enemies on condition of their laying down their arms, or as he termed it, their _iron_, slew all those who, having laid down their arms, still retained the _iron_ clasps in their cloaks.[190]