Fides Publica in Ancient Rome and its Reception by Grotius and Locke

The article analyzes the Roman notion of des publica and its reception by Grotius and Locke. The Romans considered des publica a general standard of behavior for all those invested with state power. It was regarded as a legal norm with moral connotations, which applied especially, though not exclusively, to exceptional situations, such as wars. Grotius appears to have been the first since Antiquity to rediscover the notion of des publica as a fundamental norm of public law; for him, it became especially valuable as a criterion for determining the legality of civil war and resistance. This understanding of des was also adopted by Locke, who argued that the people had a right of resistance in case the government structurally violated its trust. Contrary to the dominant view in the literature, this article shows that Locke's concept of trust was influenced not only by peculiarly English ideas about political trusteeship, but also by the Roman notion of des publica.