 The computational semantics landscape contains a few landmarks in which the concept of a default figures prominently, albeit under different labels. I have already discussed the role of defaults and inheritance reasoning in artificial intelligence research in the example of SDRT. This kind of research in computational linguistics is arguably the closest to theoretical linguistic semantics and pragmatics in that it directly appeals to human practices in reasoning. Pelletier &amp; Elio (2005) refer to this characteristic as the psychologism of nonmonotonic logics, and thus a property that was so fiercely banished from logic by Frege as a form of a ‘corrupting intrusion’, in that ‘being true is quite different from being held as true’ (Frege 1893: 202). Pelletier and Elio write: