Abstract

Proponents of probabilism argued that 'when an opinion is probable it may be followed even when the contrary opinion is more probable'. Gabriel Vazquez (1549-1604) was the first Jesuit theologian to defend and expand this doctrine. The prevalent theory of sovereignty at the time held that: (1) when sovereigns are victims of wrongs, they take on the role of international judges (thus just wars are just punishments); and (2) the sovereign need not stand before the judgment of any other human being. The conjunction of probabilism and the idea of the sovereign as a superior judge made it conceptually possible for a war to be just on both sides. The reason is that probabilism allows two sovereigns to inculpably carry out two conflicting but probable judicial sentences about the same case. Confronted with this problem, Vazquez decided to eliminate the overlap between sovereign jurisdictions by revising the then dominant conception of sovereign supremacy and proposing criteria for determining > the competent forum to settle sovereign disputes. His views developed during his involvement in the controversy about Castilian claims to the Portuguese throne