Hugo Grotius, Moral Scepticism and the use of arguments in Utramque partem

Abstract

The use of equally compelling arguments both for and against the truth of a proposition were known in the Renaissance as arguments in utramque partem. Early modern sceptics used arguments in utramque partem in order to show that one cannot ground morality on safe grounds, for the arguments which are presented in favor of the idea of justice could be neutralized by equally compelling arguments against the idea of justice. In this paper, I argue that Hugo Grotius tried to refute this kind of moral scepticism in his main philosophical writings, De jure bellic ac pacis and De jure praedae commentarius. Against the sceptic, Grotius seeks to establish that the reasons which are consecutively presented for and against the idea of justice are not incompatible with each other.