自修辭視野檢視《墨子‧天志》三篇思維論證

Abstract

本文藉助西方修辭學的概念，亦即「在任何一個問題上找出可能說服方式」，探討〈天志〉三篇的思維歷程。得知〈天志〉三篇論證「天」的性質，是經過「天的普遍性、規範性」、「天的超越性、起源性」、「天的意志是兼愛」三個步驟；當中運用了修辭學的例證法、修辭式推論、類比推論等論證模式。循此論證步驟，可以看出〈天志〉的目的，主要是藉由論證「天」的性質，使「兼愛」成為具有形上意義的道德本體，是一種「神性意志」式的「功利主義」理論系統。這三個論證步驟並非完美無缺，在盡最大努力實踐「自我（們）說服」的修辭學要求下，可從刪除謬誤的類比推論，安頓「天」所具備的「正義」和「政治」兩義，以及改換難以證實的前提等修訂、調整，鉤勒出由〈天志上〉到〈天志下〉，最後〈天志中〉的思維軌跡。

This paper explores the course of thought in the three chapters of "Heaven's Intention"using Western Rhetoric, i.e., ascertaining possible methods of persuasion for any particular issue. It discovers that the three chapters demonstrate the character of "Heaven" following three steps: the universality and normativity of Heaven, the supremacy and origin of Heaven, and the Heaven's Intention as universal love. In constructing this argument, rhetorical devices such as paradeigma, enthymeme, and analogical inference are used. Through these steps, "Heaven's Intention" primarily aims to make "universal love" as a metaphysical moral noumenon by demonstrating the character of "Heaven." "Heaven's Intention" is a theoretical system of utilitarianism by divine will. These three steps are not without flaws. Under the Rhetoric requirement to exert our utmost in striving for "self-persuasion," the course of thought is from "Heaven's Intention I" to "Heaven's Intention III" and, at last, to "Heaven's Intention II" is outlined by eliminating fallacious analogies, distinguishing properly the two meanings "justice" and "politics" of Heaven, and changing the premises that are difficult to verify.