Reason

One of the important concepts in Chinese thought. Its literal meaning is the course of things, the logical law of things. The word 'li' does not appear in the Analects or Laozi, and the word 'li' appears only briefly in Mencius, but appears frequently in works from the late Warring States period such as Zhuangzi (external chapters and miscellaneous chapters), Xunzi, and Han Feizi. Zhuangzi asserts that the Way is in all things, and explains the principles of all things while questioning the relationship between the Way and things. Xunzi also contains 'principle of facts' and 'principle of things', and Han Feizi develops the Way as law and specifies the relationship between the Way and reason, making it even clearer that reason is the principle of individualization and specialization. While this idea of ​​principle was further developed in the Han dynasty's Huainanzi, Confucian documents influenced by Taoist speculation from the end of the Warring States period through the Han dynasty produced the theory of heaven and human desires in the Book of Music, and the theory of "reasoning one's nature through the pursuit of truth" in the Shuogua chapter of the Book of Changes, which had a great influence on later generations.

The concept of Li was given a fundamental interpretation in the Wei-Jin Xuanxue in connection with the debate on existence and nonexistence, and in Chinese Buddhist studies during the Six Dynasties, Sui and Tang, it became a completely fundamental metaphysical concept based on the logic of body and function, which led to the theory of later Song Buddhist studies. In particular, the Huayan school of thought gave birth to a religious philosophy that regarded the ultimate state as the world of Li, called "Riji Muge" and "Riho-kai". In the neo-Confucianism of the Song Dynasty, Li played an extremely important role alongside Qi. In the Cheng-Zhu school, there is a principle in every thing, and it is called "Ri ichi bun shoku" (one division of Li), and based on the theory that nature is principle, he advocated the theory of "investigating things and exploring the truth", which seeks to manifest the principle inherent in oneself by investigating the truth of things and objects. This was an attempt to explain the agreement between the laws of existence and moral norms by making Li the principle of individual things and at the same time a universal principle. Since Zhu Xi (Zhu Xi), various ideas have emerged regarding the nature of principle and the relationship between principle and qi.

[Akira Oshima]

Seiichi Onozawa et al., eds., Thoughts on Qi (1978, University of Tokyo Press) ▽ Keiji Yamada, Zhu Xi's Natural Science (1978, Iwanami Shoten)

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

中国思想における重要概念の一つ。その字義は物事の筋目、事物の条理法則をいう。理という語は『論語』『老子』にはみえず、『孟子(もうし)』にはわずかに「条理」の語がみえるだけで、戦国後期の『荘子(そうじ)』（外篇(がいへん)、雑篇）、『荀子(じゅんし)』『韓非子(かんぴし)』などに多くみえる。『荘子』では道がすべての事物にあるという主張から、道と事物とのかかわりを問題にしながら万物の理が説かれている。『荀子』にも「事理」「物の理」がみえ、『韓非子』では道を法として展開するとともに、道と理との関係を規定して、理が個物化・特殊化の原理であることをいっそう明確にした。こうした理の観念は漢代の『淮南子(えなんじ)』で深められる一方、戦国末から漢代にかけて道家の思弁の影響を受けた儒家文献において、『楽記』の天理・人欲の論、『易経』説卦伝(せっかでん)の「窮理尽性」の説がつくられ、後世に多大の影響を与えた。

　理の概念は、魏晋(ぎしん)の玄学において有・無の議論とかかわって本体的な解釈を施され、六朝隋唐(りくちょうずいとう)期の中国仏教学のなかで、体用の論理を根底に置きながら、後の宋(そう)学の理につながる完全に本体的な形而上学(けいじじょうがく)的概念となった。とくに華厳(けごん)教学では「理事無礙(りじむげ)」「理法界」という、究極の境地を理の世界としてとらえる宗教哲学が生まれた。宋代の新儒学においては、理は気と並んできわめて重要な役割を果たした。程朱学では、一物に一理があり、「理一分殊」と称し、性即理の説から、事事物物の理を窮めることによって己に内在する理の発現を図るという「格物窮理」説を唱えた。これは、理を個物の原理と同時に普遍原理とすることによって、存在法則と道徳規範との一致を説こうとするものであった。朱熹(しゅき)（朱子）以後、こうした理の性格や理気の関係をめぐり、さまざまな考え方が出された。

［大島　晃］

『小野沢精一他編『気の思想』（1978・東京大学出版会）』▽『山田慶児著『朱子の自然学』（1978・岩波書店）』

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