摘要: | The formal logic system was very helpful in contemporarily philosophical researching, especially in the field of metaphysics and philosophy of science. Nevertheless, in contrast to the importance of modal logics to metaphysical issues, the epistemic logics which founded by J. Hintikka obviously did not occupy the main position in the area of epistemology due to the loose connection between epistemic logics and epistemology. In other words, the epistemic concepts such as knowledge, belief and justification are still far from satisfactory explanation in terms of the development of epistemic logics. Thus, one of the goals in constructing appropriate formal system of epistemic logics is to clarify the puzzles of knowledge, for example the problem of iteration of knowledge, or say KK principle. As I have known so far, there are three main approaches to improve the connection between epistemic logics and epistemology. The first one is dynamic theory of knowledge which represents the change of epistemic states in terms of the expansion, revision and contraction functions proposed by AGM theory. The second is the justification logics to construct the formal systems to represent explicit knowledge. The last strategy is the epistemic theory proposed by T. Williamson who contended the ignorance or the limit of cognitive system about epistemic states. In this program, I attempt to reexamine the puzzles in epistemology such as the threat from skeptics or the definition of knowledge by those approaches mentioned above. 形式邏輯系統對於澄清哲學概念是相當有幫助的,尤其在形上學及科學哲學領域中特 別明顯。然而,相較於模態邏輯在當代形上學研究中的重要性,從 1960 年代以降所發 展的知態邏輯,卻一直未能在知識論的討論中佔據主要地位,或者尚未適切地以知態 邏輯說明與知識論相關的知態概念,如信念、知識及證成等。建構知態邏輯系統的要 求之一即在於能夠用來描繪知識的樣態,例如複數模態問題,亦即「某人知道」是否 蘊涵「某人知道自己知道」的問題等。對於如何建立知態邏輯與知識論的連結,基本 上可以分成三種進路:(1)80 年代的動態知識理論,尤其是 AGM 理論,藉由信念變遷 的過程描繪知識狀態;(2)90 年代由阿特莫與費廷提出的證成邏輯,試圖建構明確知識 (explicit knowledge)的邏輯系統,忽略隱含知識(implicit knowledge)的部分;(3)2000 年 提姆斯‧威廉森提出的知識理論,則訴諸於人類知識的限制,即知識狀態有「無法知 道(ignorance)」的部分。在計畫中,我想要嘗試如何從這三種進路討論知識論問題,包 括懷疑論或知識的定義等。 |