The Default Context,

The term "presupposition" originates in the philosophy of logic, where it is used to denote a special type of implicit information which must be true for the sentence in question to have a truth-value. The debate between Russell and Strawson plays an important role in launching the research into presuppositions and the introduction of pragmatic presupposition by Stalnaker provides a different perspective on how the presuppositional phenomenon can be approached and interpreted in pragmatic terms.The purpose of the first part is to present a review of previous research on presupposition. It is maintained that two conceptions of presupposition are dominant in the literature. The semantic conception approaches presupposition from the truth of a three-valued logic, and views presupposition as a proposition the truth of which is a precondition for the truth-value of the presupposing proposition. The pragmatic conception characterizes presupposition from the perspective of language use, and regards presupposition as a major factor of the context, belief and knowledge state of the addresser and addressee. It is argued that the pragmatic and semantic notions of presupposition are not incompatible with each other and that the so-called semantic presupposition is actually a sub-case of the pragmatic presupposition.I adopt the concept of pragmatic presupposition in its narrow sense. Pragmatic presupposition is highly dependent on the contextual factors. In the second part, I try to illustrate the presuppositional phenomenon through context.Project problem, which cannot solved by semantic presupposition can have abetter solution by considering context. We should have a context set to choose as the database, from which we select the suitable context under certain rules for the choice of presupposition. Surely the context set can not solve all the problem, and some other factors should be considered.