Does the Problem of the Incommensurability Exist in Aristotle? An analysis from the doctrine and hermeneutics of Paul Karl Feyerabend: Paul Karl Feyerabend holds a particular hermeneutic with regard to Aristotle’s scientific work. He invites to rethink the contemporary science from an “Aristotelian program of investigation”. He assures us that if science assumes his way of proceeding, the presence of metaphysical elements would not mean a problem for us. Our purpose is to make a critical analysis of the scope of this invitation and to intervene in the discussion of whether or not exists in his scientific practice the problem of incommensurability – as it is understood by Feyerabend. For this, we will show how Aristotle’s understanding of the phenomenon establishes a unity between facts and theories where the problem of incommensurability cannot be established.