佛教逻辑学的论辩解释与认知解释——陈那、法称与因明

The Dialectic and Epistemic Interpretation of Buddhist Logic:Dignāga,Dharmakīrti and the Hetuvidyā-Tradition

佛教逻辑有别于西方形式逻辑的一项重要特征,在于对论证前提为真的强调,并在此基础上提出了著名的"因三相"理论。论证前提的真,在陈那著作中又被理解为辩论主体将该前提确定为真。这种"确定"体现为文献中对"极成"(prasiddha)、"成"(siddha)、"决定"(ni?cita)、"见"(d???a)、"已知"(vidita)的强调。这些表达辩论者认知状态的词汇,皆可概括为佛教逻辑中的"认知算子"(epistemic operator)。本文通过研究东亚因明与法称两个传统对陈那《正理门论》中"决定同许"的理论设定的不同解释,说明因明传统在陈那奠定的方向上,进一步采取了"论辩解释"(dialectic interpretation),将"确定为真"解释为在辩论的情境中为辩论的双方承认为真(共许、同许)。法称《释量论自注》对陈那"决定同许"的解释,则表明由他开启的传统在陈那的基础上,进一步采取了"认知解释"(epistemic interpretation),将"确定为真"解释为在认识论的意义上得到确定(ni?cita/ni?caya,决定),即为有效认知的手段(量)所证成。这是因明传统与法称传统的一项根本差异。因明传统对辩论术的关注,极有可能反映了法称以前印度学界对陈那思想的诠释路径。

A basic feature of Buddhist logic which distinguishes it from Western formal logic is that the Buddhist conception of what makes an argument good is grounded on the intuition that a good argument should start from true premises.In Buddhist logic,the truth of a premise is usually understood as being ascertained to be true by both the proponent and the opponent in a debate.Hence,the common ascertainment by both sides in debate,which is a special kind of epistemic condition,plays an essential role in defining the truth of a premise and in elucidating the standard of a good argument.Vocabularies used by Buddhist logicians to refer to this kind of epistemic condition,like siddha"established,"prasiddha"well established."niscita"ascertained,"drsta"observed"and vidita"known,"are considered by the present author as the epistemic operator in Buddhist logic.This paper is a preliminary study of the interpretation of this kind of epistemic operator by Buddhist logicians.In Nyāyamukha 2.2,Dignaga(c.480-540 CE)claimed that not only the logical reason’s(hetu)being a property of the subject(paksa)but also the relation of the logical reason to the similar instances(sapaksa)and to the dissimilar instances(vipaksa)should be"ascertained by[both]the proponent and the opponent"(vadiprativadiniscita).By comparing the interpretation of this claim in the East Asian tradition of Buddhist logic,i.e.,the hetuvidya-tradition,with the interpreation of it by Dharmakirti(c.600-660 CE),this paper finds that the hetuvidya-tradition held a dialectic interpretation of the epistemic operator in Buddhist logic.The"dialectic"interpretation means that an expression’s being"ascertained"/"[well]established"/"known"is simply to be equally accepted by both sides in debate on account of whatever evidence.In contrast,Dharmakirti,in his Pramanavrrttikasvavrtti 13,5-19,clearly refused this dialectic interpretation and proposed instead an epistemic interpretation of the epistemic operator.In this connection,he quoted and reinterpreted Dignāga’s above claim so as to support his epistemic interpretation.The"epistemic"interpretation means that an expression’s being"ascertained"/"[well]established"/"known"is to be ascertained by both sides in debate only on account of certain epistemic evidences,namely,on account of certain means of valid cognition(pramāna).