When the first generation of generative linguists discovered presuppositions in the late 1960s and early 1970s, the initial set of examples was quite small. Aspectual verbs like stop were discussed already by Greek philosophers, proper names, Kepler, and definite descriptions, the present king of France, go back to Gottlob Frege and Bertrand Russell by the previous turn of the century.

Just in the span of a few years my generation of semanticists assembled a veritable zoo of ‘presupposition triggers’ under the assumption that they were all of the same species. Generations of students have learned about presuppositions from Stephen Levinson’s 1983 book on Pragmatics that contains a list of 13 types of presupposition triggers, an excerpt of an even longer unpublished list attributed to a certain Lauri Karttunen. My task in this talk is to come clean and show why the items on Levinson’s list should not have been lumped together.

In retrospect it is strange that the early writings about presupposition by linguists and even by philosophers don’t make any reference to the rich palette of semantic relations they could have learned from Frege and later from Paul Grice. If we had known Frege’s concepts of Andeutung – Grice’s conventional implicature – and Nebengedanke, it would have been easy to see that there are types of author commitment that are neither entailments nor presuppositions.