The TCL system, designed to deal with type presupposition justification, especially of the complex sorts found in coercion and aspect selection, has many other applications. It can analyze fine-grained shifts in meaning using fine-grained types. It offers a novel perspective on adverbial modification. In dealing with resultatives and nominalizations, the system provides a natural treatment of optional arguments. We have also seen how it yields a new way of thinking about metaphor and about loose talk. It remains to be seen whether it can be used to say anything interesting about vague predication. At present I do not see anything special emerging from the TCL formalism.

Integrating ordinary presuppositions

Throughout this book I have spoken of type presuppositions. And I've argued that the formulas introduced by presupposition justification are part of presupposed content. But what about content level presuppositions? Do they fit into the TCL approach? Many presuppositions come from particular lexical elements, the so-called “presupposition triggers.” Many lexical items are presupposition triggers. Most change of state verbs, like like buy, sell, loan, borrow, heal, etc. have lexical presuppositions, which are the preconditions that have to obtain before the actions or transitions they denote can take place. Their preconditions, e.g., of ownership or physical possession, obey all the classical tests for presuppositions; they take wide scope over various operators like negation or the operator associated with a question. Such change of state verbs also have post-conditions, the conditions that obtain after the event denoted by the verb has taken place.