This paper discusses Martha Craven Nussbaum's position in The Fragility of Goodness regarding Isaac's sacrifice (Genesis 22), as compared to Ifigenia's in Aeschylus's Agamemnon. The discussion is developed under two perspectives. In the first place, Aristotle's central elements of the prudent deliberation are brought out, in order to examine if they are present in Abraham's accounts. Secondly, Nussbaum's critique to monotheistic faith –based upon an irrational way of inscrutable authority that imposes and supports inhuman rules– opens us to a question: what does the biblical God provide for ethical requirements? In order to answer this point, sacrifices in the Old Testament are examined under the light of Franz Hinkelammert and Rene Girard's analysis. The conclusion of the paper is that the question regarding the biblical God is intimately linked to that regarding one's responsability towards another person's life when confronted with deities that promote violente.