Communicating modern biotechnologies is certainly no easy task. To tackle such a complex and future-oriented assignment, help may arrive, paradoxically, from the past, from ancient rhetorical tradition, and in particular from Aristotle, the most renowned rhetoric teacher of all time. In his Rhetoric, Aristotle suggested that to be persuasive speakers should make use of widely accepted opinions (endoxa), i.e. the common sense shared by all. Common sense is expressed in common truths and value-laden maxims. Common sense, however, is not flat but dialectical, in that it includes contrasting subjects. While reasoning, orators do not just passively report a conception of an unchanging world, but they reproduce the contrasting conceptions included in common sense. In the case of the debate about Biotechnologies, the contrasting conceptions can be found in the Natural/Artificial dualism, in the dichotomy between an attitude marked by obscurantism and suspicion of scientific and technological innovation and that of a scientistic attitude.