Abstract This paper shows that modern monetary theory can be better understood through the differences between Menger and Walras. Since the 1980s, attempts to establish coherent microfoundations for monetary exchange have brought Menger's theory of the origin of money to the forefront and sent walrasian methods to the backstage. However, during the first decade of the twenty-first century, models inspired on mengerian monetary theory, mainly represented by the search monetary approach, are trying to reintroduce neo-walrasian elements. This paper aims at clarifying the main theoretical implications of this movement, through an analysis of the Menger–Walras divide on money. This divide allows us to show new proof of the deep theoretical differences among the so-called marginalist authors and of the richness of this historical period as a source for modern economics.