In 1537 the Spanish Dominican Francisco de Vitoria, Prime Professor of Theology at the University of Salamanca, delivered a lecture entitled De indis whose purpose was, he declared, to discover ‘by what right the barbarians’ – by which he meant the American Indians – ‘had come under the rule of the Spaniards’. For although, he professed, the conscience of the Spanish kings and their advisors was of itself sufficient guarantee that everything ‘had been well-done’, all men are compelled to consult the wisest and best-informed persons they can find before reaching a decision on any issue where matters of conscience are involved.

Vitoria's relectio belongs to a tradition of ritual legitimation which the Castilian crown had, since the later Middle Ages, regularly enacted when confronted by uncertain moral issues. The conclusions which the crown's advisors reached on these occasions were frequently ignored since, as Vitoria himself observed, kings were, of necessity, pragmatic beings compelled to ‘think from hand to mouth’. But the declarations issued by the theologians and jurists on crown policy formed an important part of the ideological armature of what, after the defeat of the comunero revolt in 1521, has some claims to being the first early-modern nation state. With the accession of Philip II, that state had, effectively, secured the consensus of its own political nation.