摘要
本篇論文的討論起點來自柏拉圖如何面對靈魂能夠認知真理的這個可能性。柏拉圖設立那與變動的感覺現象完全分離的「不變動的『相』」作為知識得以成立的條件，這個歷史緣由可從亞里士多德的記載當中知道：一方面，柏拉圖認同克拉梯樓斯與赫拉克利圖學派所主張的感覺現象的永遠流動、無一停留，並因此認為絕不可能有關於感覺現象的知識，然而，另一方面，那致力於倫理事物研究的蘇格拉底則堅持必定有那可被定義的知識對象得以被思考與認知；由於受到這兩方所堅持的信念，柏拉圖則在為了拯救現象並使思考與知識得以可能的情況下，他設立了那必須與變動的感覺現象完全分離的相來作為感覺現象之所以如此存在的原因，並在透過那分有相的感覺現象當中，靈魂得以思考並回憶起關於相的知識，而由此拯救現象並保全靈魂得以思考且獲得知識的可能性。
然而，柏拉圖的分離相論卻有可能引發諸多困難，這主要可由《巴曼尼德斯篇》裡的少年蘇格拉底所遭遇到的三個困境所表現出來：○1少年蘇格拉底對於是否有卑下者的相的存在，顯得猶疑不定；○2由於無法回答相與現象之間到底是如何分有，以致於分有成為不可能；○3更進一步地，正是由於相與現象彼此的完全分離，以致於原本肩負拯救現象這使命的相，到頭來卻反而根本無法拯救現象，而且也面臨無法為人所知的這個最大困境。
這三個困境其實正是柏拉圖真理之路---愛智者如何能擁有那與現象完全分離的相的知識？---所蘊含的兩個一體兩面的論題：第一，思考與知識的可能性如何成立？也就是，相如何拯救現象？第二，愛智者要以什麼樣的方法才能正確地獲得相的知識以成為真正的哲學家？關於第一個論題，筆者認為，柏拉圖在《巴曼尼德斯篇》第二部分的八組推論當中提出一種具有數特徵的存有論，這個存有論綿密、細緻地論說《蒂邁歐篇》裡的宇宙生成論以及「未成書研究」裡的原理論，在這當中，相拯救現象的可能性乃在於---神以其意願與叡智將相形塑於這個數存有的世界並因此使那些在場域裡生滅變化的現象獲得一致性，如此，神的意願（i.e.善）乃作為相得以拯救現象的最具統馭力的原因與原理；關於第二個論題，那能使少年蘇格拉底獲得真理以成為哲學家的訓練，正是那以合理論說所掌握的相為對象的訓練，筆者認為，柏拉圖在這個訓練當中，試圖透過假設法的運用，使得愛智者能緊守在對「是」（i.e.相）的追求上，並得以在一步步的往上探求當中，在最後能以最終的決定性原因---善---來束縛住所有的相，如此，當愛智者能在「善」的指導下以合理論說來正確地指出每個相的真實本質時，這個愛智者也就成為真正的哲學家。
在這樣的解決方式當中，柏拉圖證成了靈魂能夠認知真理的可能性，為自己的真理之路尋得一個合理的立足點。柏拉圖在這當中所奮力搏鬥的，主要並不是亞里士多德在《物理學以後諸篇》A 6.987a33-b10所提及的這些哲學家，而是歷史上的這位伊利亞哲學家---巴曼尼德斯：柏拉圖分離相論的核心來自巴曼尼德斯其毫無生滅變動的「完滿的是」，然而，柏拉圖拯救現象以及保全思考與知識的可能性的這個企圖，卻又是必須對巴曼尼德斯的「完滿的是」提出批判。而在柏拉圖藉由這兩個假設與八組推論來與巴曼尼德斯奮力搏鬥當中，柏拉圖所完成的不僅僅只是解決分離相論所可能引來的困境，而更是走上一條不同於巴曼尼德斯的真理之路，因為現象的拯救是柏拉圖所主要異於巴曼尼德斯的地方，而那使得現象得以被相所拯救的最具統馭力的原因與原理乃在於---宇宙父親的意願與叡智，而這乃作為柏拉圖自己的真理之路的最終磐石。
關鍵詞：相論，分離，分有，善，假設法，柏拉圖，巴曼尼德斯，〈未成書研究〉，《巴曼尼德斯篇》，《蒂邁歐篇》。 / Abstract
The aim of this thesis is to show that how Plato might deal with the possibility for soul of knowing the truth. The historical reason for Plato positing the invariable Forms, which are totally apart from the variable sensible things, is remarked by Aristotle that: on the one hand, having been agreed with Cratylus and the Heracllitean doctrines that all sensible things are always in a state of flux and that no science of them exists, yet on the other hand, taking into account the Socrates’ efforts to find general definitions of ethical terms, Plato, having been inspired by both views, thinks that there must be some invariable things, i.e. Forms, which are totally apart from the variable sensible things and could only be thought with logos（or reasonable account）, as the causes of the sensible things. Therefore, the soul could recollect and think of Forms by perceiving these sensible things, which participate in the corresponding Forms. Hence, Plato saves the phenomena and secures the possibility for soul of thinking and knowing the truth by his theory of Forms.
However, there might be many problems that arisen from Plato’s theory of Forms. These problems are shown mainly by the three perplexities, which are encountered by the young Socrates in the Parmenides. First, the young Socrates is undecided about whether the base things could have their Forms, second, having been unable to solve the problem of the sharing between the sensible things and Forms, the young Socrates finally has to accept the impossibility of sharing, third, further, just owing to this totally separation that is between the sensible things and Forms, Forms finally could not save the phenomena and could not be known by anyone.
Actually, the three perplexities are the two topics of Plato’s way of truth, which is that how the lover of wisdom could know the Forms that are totally separate from the sensible things. The first topic is that, in what way the possibility of thinking and acquiring knowledge could be secured. That is, how the phenomena could be saved by Forms? The second topic is that, in what way the lover of wisdom could acquire the truth and becomes the real philosopher. As for the first, I think that Plato claims a kind of ontology, which has numerical character, in the second part of the Parmenides. This ontology provides deliberately the cosmogony of the Timaeus and the theory of the Principles in the Unwritten Doctrines that could justify the possibility of the phenomena that are saved by Forms. This possibility lies in the god’s nous and will, i.e. the world that has numerical character is fashioned by the god with Forms as model, and then the becoming phenomena that cling to the receptacle are saved and intelligible. Therefore, the god’s will is the supremely valid cause and principle of this possibility. As for the second, this exercise that can make the young Socrates as a real philosopher if he takes it into practice is the training, which takes Forms as its objects and be practiced in hypothetical method. I think the reason for Plato of using the hypothetical method is that this hypothetical method can make the lover of wisdom to cling to Forms when he is putting this exercise into practice, and in this upward process systematically, finally, he can fasten all the Forms with the final cause, i.e. the good. Therefore, when the lover of wisdom could show the real essence of each Form with reasonable account under the guidance of the good, he at that time is a real philosopher.
Under this solution, Plato justifies the possibility for soul of knowing the truth, and makes his way of truth possible. In this fighting, those with whom Plato fights are not those philosophers that are remarked by Aristotle in Metaphysics A 6.987a33-b10, but the philosopher of Elea, Parmenides. On the one hand, the key point of Plato’s theory of Forms is coming from Parmenides’ concept of Being, which is ungenerated and imperishable, yet on the other hand, the attempt for the possibility of saving the phenomena and for soul to know the truth is urging Plato to put Parmenides’ claim to the question. Then what Plato has done in this fighting, which mainly occurs in the second part of the Parmenides, is that as he is solving these perplexities, he at the same time is stepping upon another way of truth, which is different from Parmenides. In this fighting, saving phenomena is the main difference between Plato and Parmenides. The god’s nous and will is the supremely valid cause and principle of the saved phenomena and this most supreme cause is the coping-stone for Plato’s way of truth.
Keywords: Plato’s theory of Forms, separate, participate, the good, the hypothetical method, Plato, Parmenides, the Unwritten Doctrines, the Parmenides, the Timaeus.
| Identifer | oai:union.ndltd.org:CHENGCHI/G0901545052 |
| Creators | 蘇富芝, Su, Fu Chih |
| Publisher | 國立政治大學 |
| Source Sets | National Chengchi University Libraries |
| Language | 中文 |
| Detected Language | English |
| Type | text |
| Rights | Copyright © nccu library on behalf of the copyright holders |
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