Thomas Aquinas’ anthropological-metaphysical and theological understanding of inequality among men

The implications that this whole question of equality/inequality among men present in relation to the question of serfdom reveal in a special way the bridge that exists between the metaphysical-anthropological considerations and the social theory of Aquinas himself. The paper argues that, although Thomas considers a series of inequalities among men -both natural and moral-, at the same time, there can be no doubt about his affirmation of a fundamental equality among them. The identical basis of human perfection for all lies in the ontological equality attributable to all members of that species. In this regard, the argument proceeds to a metaphysical analysis of the concepts of aequalitas, similitudo, identitas and unitas, in their relation to humanitas, concluding that among men it must be said that there is a fundamental equality, not likeness. It is established that there are two ways -one positive and the other negative- to show this equality. Regarding the first way, the question of the imago Dei appears as something communis omnibus hominibus. As for the negative manifestation of equality, there is the question of servitude, whose examination in Thomas Aquinas is closely linked to the teaching of two Fathers of the Church, Augustine and Gregory the Great. In conclusion, it is established that for Aquinas there are no people innately superior to others, and that, consequently, to judge that some have de iure certain authority over others, the moral merit of the subjects must be taken into account.