本文的目的是藉由文獻分析比較傅可思(Michael Allen Fox)在不同時期就動物權利相關具體應用問題，「動物實驗」及「素食主義」兩個論域所持的論點及立場，檢視他如何闡述人類和動物之間的道德關係，進一步詮釋其立場轉變的涵義。 我的研究發現，傅可思動物權利理念轉換的內涵其實牽涉到複雜的傳統與現代的交織！整體而言，他的倫理理念是以「人類–自然之關係」為理解進路。早期的倫理觀是以「人類中心主義」為要，目前則是博採眾議，具有「非人類中心主義」的理念，但在應用上，務實地肯認道德能動者的主體性，訴諸道德行動者「食素良知」的視野，會讓我們決定我們在自然社群裡的位置，可說具有「修正人類中心主義」的意含。依傅可思的理念轉換為例，也足以說明西方環境倫理學的發展趨勢，可以稱得上是一部動物解放運動爭鳴與分歧的歷史；人類的種種作為都是其特定價值體系的某種體現，傅可思也參與其中，在不同階段展現不同觀點的道德尺度和價值取向。
Through analyzing literature, this study aims to compare the arguments and stances held by Michael Allen Fox during different time periods regarding practical animal rights issues such as "animal experimentation" and "vegetarianism"; inspect how Fox explains the moral relationship between humans and animals; then go one step further and interpret the meaning behind Fox''s change of stance. This study found that the meaning behind Fox''s change in animal rights beliefs is actually related to the complex interactions of past and present. On the whole, Fox''s ethics beliefs followed the "relationship between man and nature" route of understanding. While Fox''s earlier ethics view emphasized "anthropocentrism", his current view is the combination of many and is based on "non-anthropocentrism", yet pragmatically recognizes the subjectivity of moral agents. Adopting the "vegetarian conscience" view of moral agents will allow us to determine our role in the natural community, and implies a "revised anthropocentrism". Fox''s change in beliefs also demonstrates that the trend of development of western environmental ethics may well be called the history of the rise and divergence of the animal liberation movement. Everything people do is the product of a particular value system. The same holds true for Fox, who has shown different views of moral standards and value orientations during different periods of time.