Two scenes: in the first, longer one (in two epigraphs), we will recall again the «classical» core of a famous problem of «Greek logic», the «non-being» (linked to the «principle of non-contradiction»), from a reading of Parmenides and some extracts from the end of Plato's Sophist, as well as from Poetics and the book «Gamma» of Aristotle's Metaphysics: it will be shown in what sense such «non-being» is but the right name, undermining all faith and confidence, for saying the rigor (mortis) of thought (i.e.: nothing to see); the second (last epigraph), besieged by the first one, expose one, or two (einmal ist keinmal), of its translating extremities (mischiefs): the grammatical-political problems of «heterogenesis» and anarchist «anybody» in Antonio Machado and Agustín García Calvo (from a few laconic forays into other more or less «contemporary» readings).