In search of an answer to the question posed in the title, this study turns to the laws of the Pentateuch, Proverbs and the books of Amos and Isaiah 1-39, and concludes that expressed within them are two ethical systems, of which Yahweh is the originator, foundation and guarantor. One is based on the creation, the work of Yahweh, and intrinsically universal. It is the only one to be found in the earliest sapiential writings and in the discourse of Amos and Isaiah. The other is based on the relations between Yahweh and his people Israel, and intrinsically particular. It is expressed above all in the laws of the Pentateuch, but also in the historical books and in some of the prophetic books. The author ends by making a plea for an ‘updating’ ...