ラシイ文における推論構造 - BCCWJとCEJCを用いて -

Abstract

Rashī, one of the epistemic modalities in Japanese, has semantic functions such as hearsay and presumption. The research focuses on the latter in Rashī sentences and aims to analyze the process of sentence formation. The analysis is based on four types of inference, i.e., deduction, induction, analogy, and abduction, using examples provided by "BCCWJ (Balanced Corpus of Contemporary Written Japanese)" and "CEJC (Corpus of Everyday Japanese Conversation)". The results show that even Rashī sentences in deduction can convey a high degree of speaker’s subjectivity, in contrast to the conventional meaning of Rashī, which describes an event from an objective point of view. It is seldom used when the main proposition deals with one's assumption or personal belief. Rashī-sentences, in the type of induction, are suitable for describing an event in the form of statistical generalization. Analogy, in which a comparison is made between or among some events, can lead to Rashī-sentences as conclusions, even if the information is not fully suggested in the context. However, this kind of logical leap still needs to be discussed in terms of the speaker's subjectivity. Of the four types of inference, abduction may be the most appropriate structure for Rashī sentences to describe circumstances by gathering the most possible and plausible examples. It is also found that abduction has two directions: either to find the cause or to draw a conclusion.