For the logical criterion of the impossibility of a concept consists in this, that if we presuppose it, two contradictory propositions both become false; consequently, as no middle between them is conceivable, nothing at all is thought by that concept.
Izan ere, hauxe da kontzeptu baten ezintasun-seinale logikoa, alegia aurre-suposatu beraren azpian, elkarren kontraesale diren bi proposizio aldi berean direla faltsuak; beraz, ba, nola horien artean ez dagoen beste hirugarrengo bat bururatzerik, kontzeptu horren bidez ezin daiteke ezertxo ere pentsa.