目的與工具之辨－楊朱思想的論證基礎與根本關懷

本文旨在闡明楊朱學派「爲我」主張之論證基礎與思想要旨。筆者試圖說明：一、楊朱學派的「爲我」之說，係以「身物輕重」之辨爲論證基礎。墨家主張「功利原則」，認爲當身、物之間發生價值衝突時，於利、害中進行比較權衡，乃是判斷身物先後的原則。楊朱學者根本反對此一觀點。他們認爲，身、物關係乃是目的與工具之別：工具爲目的存在，而非目的爲工具存在；生命自身就是其目的，而非爲他物存在的工具，生命之價值則是不可以被權衡計算或交換的。此即是「拔一毛而利天下不爲也」的論證基礎所在。二、「爲我」之說所關心的，並不只是形軀生命之我而已。楊朱學派關切的是「全性保真」問題：他們認爲欲保全人之真性，必須不受世俗價值之拘束，因此必須「不以物累形」，不以外在世俗價值爲生命之目的。理由是：自然真性就是人生的目的與絕對價值，不可以用世俗工具價值來交換；任何形式的價值交換都是將人的規性工具化，是對貭性的破壞。此即以目的、工具之辨的論證方法爲根基。

關鍵字

拔一毛而利天下不爲也；身物輕重；莊子；墨子；功利主義原則

並列摘要

This paper tries to analyze Yang Zhu's theory of ”wei-wo” (”everything for oneself”). The main ideas may be summed up as follows. 1. Yang Zhu made his argument by distinguishing the significance of human life and the significance of other things. As an opponent to the utilitarianism of Mohists, who advocate exchanging lives for social benefits, Yang Zhu insisted that lives are not exchangeable because they are ends to themselves, not tools for any other purposes. 2. Yang Zhu concerned not only physical lives but also the conservation of human nature. He took ”hsing” or ”zhen”, the true human nature, as the ultimate value of life, and maintained that this human nature should not be traded or sacrificed for any artificial or social value. Human nature is an end to itself and cannot be traded as a tool for other things in any way. Thus, Yang Zhu's proposal, ”unwilling to pull out one hair for the benefits of the whole world,” could be understood as a question open to everyone: Do you want to live life as an end to itself or as a tool?