當代陳那因明研究再審視---與沈劍英、鄭偉宏、Eli Franco 商榷

漢傳陳那（Dignāga,480－560）因明，最初起源於古印度，公元7世紀，由創立了唯識宗的玄奘(600－664)傳入中國，曾一度盛行，此後幾經起伏。到20世紀70年代，中國大陸經過了「文化大革命」的十年動亂，本來就很薄弱的因明學，幾近滅絕。於是自1980年代起，中國社會科學院興起一波「搶救因明絕學」熱潮，試圖搶救瀕臨滅亡的「漢傳因明」。因此漢傳陳那新因明研究，再度蓬勃發展，此時百家爭鳴，時有論辯商榷之文。但迄今為此，尚有兩大爭議問題並無共識。本文即是為了處理當代陳那因明研究之兩大爭議問題，此二議題目前在學界中繼續存在爭議。其一是陳那因明三支論式之邏輯體系屬性，其二是玄奘「唯識比量」作為共比量能否成立。首先，筆者跳脫既有框架，以五支論式與三支論式之對比，解決陳那因明喻體是否「除宗有法」的爭議，得出新因明三支論式(宗因喻)，其中喻支實包含五支論式當中喻、合二支的功能之結論。鄭偉宏堅持喻依、喻體除「宗有法」，是就原喻支部分立敵共許的要求而言；姚南強等認為喻體不除「宗有法」，其立論是站在合支上證宗的運用。陳那新因明三支論式，將五支論式當中喻、合二支的功能，畢其功於一支(新因明的喻支)，而造成鄭、姚雙方各摸其象，各言其是。只要把新因明三支中的新喻支，還原展開為五支形式的喻、合二支，就可以解釋雙方的歧見。在了解喻體在「合支」不除「宗有法」後，筆者以為: 陳那三支論式中喻體在「合支」上的運用，符合演繹法。其次，漢傳因明的開創者玄奘曾寫下「唯識比量」，欲以此比量來成立唯識的理論。許多唯識家把「唯識比量」當作顛簸不破的比量，因而叫它「真唯識量」。「唯識比量」，只有短短的二十四個字 ――「真故極成色不離於眼識，自許初三攝眼所不攝故，猶如眼識」，其篇幅簡短，歷來眾說紛紜。「唯識比量」之爭論已超過一千年，迄今亦並無共識。對於玄奘「唯識比量」作為共比量能否成立的爭議。筆者提出以往學者未曾提及之新觀點―― 即除了因支必須立敵「共許」之外，以「唯識比量」之喻體在除「宗有法」後，能否全然滿足「立敵共許」的要求，作為「唯識比量」是否為共比量的判斷標準。筆者以為:「唯識比量」因法「自許初三」所增加的立方自許之「他方佛色」，在喻支上起了一定的作用。「唯識比量」喻體：「諸『自許初三攝眼所不攝』者，皆『不離於眼識』」，包含了「他方佛等色，不離於眼識」；而「他方佛等色，不離於眼識」，無法滿足「立敵共許極成」的要求。因此筆者以為: 若嚴格地以奘門師生對於漢傳因明「三種比量」嚴謹的定義來重新審視，筆者認為「唯識比量」恐怕也只是自能立，而非真能破。而沈劍英、鄭偉宏等雖論述「唯識比量」是「自比量」而不是「共比量」；然而，其論述的理由不夠正確，無法反駁唐疏中的解釋，本文亦予以指出。 Eli Franco 於 2004 年發表的「玄奘對唯識的證明」(Xuanzang’s Proof of Idealism [Vijñaptimātratā], Hōrin 11) 一文，說到:「(相違決定量)至少到目前為止符合“因三相”的條件，因此，元曉畢竟成功地廢除了玄奘的輝煌推論(唯識比量 )。」對於Eli Franco有關「相違決定量」的觀點，筆者不能認同。筆者認為: Franco忽略了因明宗依、因、喻皆須「立敵共許」的要求，很可能其對「因明規則」或「唯識學派」的理論有所誤解。本文亦一併予以指正。

關鍵字

真唯識量；比量；鄭偉宏；演繹法； Eli Franco

並列摘要

Dignāga’s Buddhist Logic (yinming), which was developed in Indian and brought to China by Xuanzang(600－664), had once flourished in Tang Dynasty but declined later. There was some trace of revival during the late Ming Dynasty, but it has not received any serious study over the remaining part of the Chinese Buddhist history until 1980’s when scholars from the Chinese Academy of Social Science attempted to study it. Since then, a group of Chinese scholars have studied and publish on Dignāga’s Buddhist Logic. So far, these scholars have been debating on two important questions, namely, " Whether Dignāga’s syllogisms is analogy, inductive or deductive?" and " Is it possible to see Xuanzang’s “Inference for Consciousness-only (vijñaptimātratā)” as a “universal inference (共比量)” accepted by both the proponent and opponent?" In this thesis, I am going to deal with these subjects and come up with solution to them. Firstly, to solve the argument, "should an example-body (喻體) exclude the inferential subject (Skt. dharmin) (除宗有法) ?", I convert Tri-avayava (三支) back into Pañcāvayava (五支) in which upanaya (合支) and dṛṣṭānta (喻支) are included in the dṛṣṭānta (喻支) of Tri-avayava. Zheng Weihong claims that dṛṣṭānta (喻體) and udāharaṇa (喻依) should exclude the dharmain, which is based on the dṛṣṭānta agreed by both the proponent and opponent (立敵共許). But Yao Nanqiang and a few other scholars claim that dṛṣṭānta should not exclude the dharmin, which is to prove the thesis. Dignāga merged dṛṣṭānta and upanaya of Pañcāvayava into the dṛṣṭānta of Tri-avayava. Therefore, both Yao Nanqiang and Zheng Weihong insist their arguments without settlement. I think that there is a way to reconcile their dilemma by restoring dṛṣṭānta (喻支) in Tri-avayava back to upanaya (合支) and dṛṣṭānta (喻支) in Pañcāvayava. I, thereby, hold that Dignāga's Tri-avayava is a deductive inference as long as we understand the dṛṣṭānta of Tri-avayava including dṛṣṭānta and upanaya of Pañcāvayava and dṛṣṭānta need not exclude the dharmin. Next I deal with Xuanzang's celebrated inference, which he himself proposed to defend the “consciousness-only” doctrine, the inference known as “true consciousness-only pramāṇa 真唯識量”. The debate in the history of Chinese Buddhist logic as well as of the contemporary scholars is simply that whether Xuanzang’s “consciousness-only inference” is or is not a universal inference accepted by both the proponent and opponent. In my view, the “qualification簡別” Xuanzang employed in his example-body喻體 makes the whole inference a self-granted inference rather than a universal inference. Although the two Chinese scholars I took issue with have put forward the same argument, but for a reason very different from mine, and in my view, untenable. Lately, this thesis deals with Eli Franco's endorsement of Wonhyo’s rejection of Xuanzang’s “inference”. Franco regards Wonhyo’s rebuttal as a valid inference, which successfully employs the same “qualification” strategy Xuanzang himself used to establish his. However, I found Franco’s argument not tenable because of his misinterpretation of the logical fallacy known as viruddhāvyabhicārin (相違決定量).