This paper is a continuation and development of the arguments presented in Kamio and Suzuki (1996, CLS 32). The major claim of the present paper is that the class of factive predicates is an open class. The second claim is that the nature of presupposition is basically pragmatic, rather than semantic as Kamio and Suzuki (1996) implied. The first claim is supported by the following two kinds of argument. First, there are innumerable predicates which create a factive presupposition when they are used with the past tense although they do not when used with the present tense. The contrast between It is nonsense that John will object to the chairman versus It is nonsense that John objected to the chairman exemplified our first claim. Second, there are also innumerable combinations of a verb and a predicate or a prepositional phrase which can create a factive presupposition only when they are used in the form of combined phrases. For example, It was considered against the policy for John to reimburse the customer all the amount entails that John in fact reimbursed the money. But neither consider nor against the policy can itself create a factive presupposition. Moreover, beyond the policy, in accordance with the policy, against the law, against the principle and countless other prepositional phrases can replace against the policy in the example above and preserve the factive presupposition. Thus, the class of factive predicates is finite but open, just as the class of nouns is, because countless new nouns are creatable. The pragmatic nature of presupposition, which has been widely accepted, will also be suggested if we observe many predicates and their pragmatic characteristics.