ダロウ文の推論構造 ―演繹・帰納・類比・仮説推論の観点から―

Abstract

Darō, one of the epistemic modalities in modern Japanese, is a widely used conjectural form in both written and spoken registers. The semantic function of Darō ranges from delivering a speaker’s judgment based on internal clues and seeking the hearer’s confirmation in colloquial speech to drawing conclusions from information within the given context. Although this leads to differences in the inferential structure, this study argues that there is a consistent logic underlying the various meanings in Darō-sentences. With the aim of analyzing the primary logic of such sentences, this study identifies four types of inference: deduction, induction, analogy, and abduction. This study finds that deduction and abduction are the most common types of inference. The results also reveal that Darō functions to indicate the starting point for an inference by providing a topic. In deduction ((1)-1) and ((1)-2), Darō employs tautological logic, which allows the speaker’s internal judgment and confirmation to be interpreted. Of these four types of inference, enumerative induction ((2)-1) is the least likely to occur when Darō implies a question. In the induction by projective method ((2)-2), Darō illustrates trends or tendencies within a society. Analogy ((3)-1) and ((3)-2) are suitable for Darō when predicting unknown events. In abduction ((4)-1) and ((4)-2), Darō has features of paraphrasing words and assuming the cause, respectively.