 Recall from  Section 1.2  that a deductive consequence relation satisfies Soundness. That is to say that \( \alpha \vdash \beta\) only if \( \beta \) is true in all the worlds in which \(\alpha\) is true. It is clear from the preceding examples that defeasible reasoning cannot satisfy Soundness. If \(\alpha \dproves \beta\) then perhaps \(\beta\) is true in “typical” worlds in which \(\alpha\) is true. We call a consequence relation ampliative if \(\alpha \dproves \beta,\) but there are worlds in which \( \alpha \) is true, but \(\beta\) is false. The terminology derives from the Latin ampliare, “to enlarge”, because defeasible reasoning “extends” or “goes beyond” the premises. Ampliativity and non-monotonicity go hand in hand in all but the most contrived circumstances. 