- 學位論文
生物目的性現象的科學說明之研究
A Study of Scientific Explanations of Teleology-Related Phenomena in Life
摘要
本論文探討生物目的性現象要如何被理解與說明的問題，主要回答「以目的論來說明生物目的性現象的說明模式是否可被保留？」的問題。目的論通常與「生命現象是超自然創造者有意識設計的證據」之觀點關連在一起。雖然達爾文的演化論被提出之後這樣的想法已被放棄，但生物學家與哲學家們仍然對於該如何說明生命現象的特殊性存有爭論。這反應了三個反對目的論的論題：目的論是(1)科學發展中的錯誤理論；(2)錯誤的意向性投射；(3)與因果說明的架構衝突。本論文爭論這三個反對論題都無法成立，因此目的論的說明可以被保留。 第一章討論生物目的性現象從古希臘時期到邏輯經驗論的思想演變歷程。十七世紀科學革命之前，帶有神性色彩的目的論觀點是主流；科學革命之後機械論興起，在此時代背景下使用目的論來解釋生物目的性現象開始式微，然而在目的論的發展脈絡這邊仍有Paley的神創論、以及後來生機論的目的論。歷史顯示目的論並未因科學進展而被消除。二十世紀初期哲學家朝向化約目的概念的方向來說明目的性現象，如Hempel與Nagel的功能化約方案。然而，目的概念的化約工作遇到難題，使得哲學家朝向使目的論可與科學相容的自然化方向發展。 自然化目的論希望消除目的概念的神秘性，使其符合因果說明的科學架構。自然化取向從Wright開始，接著是 Commins、Millikan、Mayr、Brandon、Ruse、與Toepfer。從第二到第四章，本論文一一討論並評析他們的理論觀點，顯示他們的立場光譜雖然分佈在反目的論和目的論之間，但都不能支持消除目的論的必要性。 為了回應第二個疑慮，本論文第五章回到一個基本問題：被目的論說明的現象究竟是什麼？根據我們的分析，生物目的性現象的目的導向性有三種：(a)生物特徵或器官的目的（生物功能）、(b)生物系統的目的（維繫系統穩定存續的系統功能）、以及(c)生物功能和系統功能趨向生存的目的（功能的來源）。這些現象顯示目的性現象並不是錯誤的意向性投射。又其中的(b)和(c)既可用目的論的說明模式，也可以用因果說明的模式來說明：(b)因為可使用整體性的概念來說明、而(c)可使用整體性與適應性的概念來說明，因而是目的論的。有人可能會質問：如果它們可以使用因果說模式，為什麼我們還要保留目的論的說明？這涉及目的論說明、因果說明與科學說明之間的關係。 第六章我應用Giere所提出的模型哲學之觀點來定位科學說明：科學表徵活動是行為人為了特定的認知目的，意圖使用模型來表徵一部分世界的認知活動。在此架構下，目的論與非目的論都是生物學家或認知者為了瞭解生物目的性現象，以不同的認知模型來表徵該現象的科學表徵活動。這蘊含了科學說明的多元主義觀點。在科學說明的模型論觀點下，目的論說明與因果說明不僅不相互衝突，而且都具有不同的認知價值，分別增進我們對生物世界的豐富理解。 根據本文的分析，由於質疑目的論的三個理由都不成立，因此本文結論說：目的論作為說明生物目的性現象的說明模式，具有保留的價值。
並列摘要
In this dissertation, I discuss the goal-directed phenomena in life, and attempt to answer the question of ‘should we hold teleology as an explanation for the phenomena of life?’ Theology is usually related to the evidence of exist of Gods, but after Darwin’s evolutionary theory, the idea is abandoned. Although, the puzzle of end-related phenomena in life still disturb philosophers. It reflects three objections to teleology: (1) the bad reputation of teleology in history; (2) the doubt of teleomentalism (3) inconsistency with causal explanations. I claim that all of them are base on false beliefs and we should keep teleology in explaining the phenomena of life for better understanding. My analysis begins with the discussions of end-related phenomena in nature from Plato to modern times. Before 17th, the mainstream for explaining the phenomena of life is teleology, but after the scientific revolution, materialism became popular. In the early twenty century, philosophers try to reduce teleological explanations to causal explanations, like Hempel and Nagel. But due to the difficulty from reducing approach, it turns to naturalize teleology. It shows that teleology did not been eliminated from history, but only performance in different ways. Naturalize teleology aims to reconcile teleology and materialism,and it began from Wright’s etiological approach, and then Cummins, Millikan, Mayr, Brandon, Ruse and Toepfer. According to my analysis, I point out that their views are not good enough to eliminate teleology. In order to evaluate the second doubt, I deal with the structure of end-related phenomena in life and suggest that a completed explanation of vital phenomena should include three different kinds of ends: (a) the ends of a function; (b) the ends of biological systems; and (c) the end of organisms (flourishing). It shows that teleological explanations could not be teleomentalism. In the explanations of (b) and (c), it may relate to the concept of holism: for the stable exit or goods of whole, and (c) may also relate to the concept of adaptation: contributions for flourishing. Though (b) and (c) could be teleology, causal explanations apply to (a), (b) and (c). However, if (b) and (c) could be explained by causal explanations, why we keep holding teleology? In order to reply this objection, I attend to the relations between teleological/non-teleological explanations and scientific explanations. Here, I apply Giere’s agent-based conception of models to scientific explanations. From his point of view, scientific representations are such a cognitive activity that agents (1) intend; (2) to use model, M; (3) to represent a part of the world, W; (4) for some purpose, P. In this picture, biologists or agents intend to use the model of teleology/non-teleological to represent the purposeful phenomena in life for the end of better understanding of life. It implies the view of scientific pluralism. In such way, teleological explanations are compatible with causal explanations. In a word, teleological and non-teleological explanations as scientific representations for end-related phenomena of life are both valuable ways to catch the nature of life. It provides a vivid and fruitful understanding to it. In the end, I conclude that because of all objections to teleology are invalid, teleology as a explanation for the phenomena of life should be held.