Research On The Existential Presupposition

The existential presupposition is a basic problem in traditional logicians inevaluation of categorical proposition reasoning usually must consider. The so-calledexistential presupposition refers to the subject or predicates that categoricalproposition the expression of the class is a non empty set, or say, subject or predicatethe indicated class cannot be empty. If the cancellation of the assumption, intraditional logic is regarded as the interpretation of some categorical reasoningeffectively is no longer available.The existential presupposition is the traditional logic in the discussion on therelation reasoning, deforming of proposition reasoning and categorical syllogism, saidone of the essential contents of the formal validity of propositional reasoning. Intraditional logic, existential presupposition includes two aspects: one is the existencepresupposition; two is the universal existence presupposition. In the discussion on theeffectiveness of categorical syllogism, but also to small existence presupposition,existential presupposition and sports items in existential presupposition difference.However, in traditional logic,"existential Presupposition" is arbitrarily as anagreement in respect of analysis and evaluation of propositional reasoning. As forwhy this agreement, traditional logic did not give a reason. This paper attempts togive a reason from the angle of modern logic, to show why need the existentialpresupposition in traditional logic propositional reasoning effectiveness of the truth inthe discussion.In traditional logic, existential presupposition, not only show that the traditionallogicians in discussing the deductive reasoning doesn’t consider the categoricalproposition the subject and predicate expression is an empty class situation, but alsoshow that deductive reasoning in traditional logic can be constructed in the proof, thecorresponding form with modern logic, therefore, both are coordinated, that doesn’texist inconsistencies, however, modern logic description of theory is more generalthan traditional deductive logic theory.