演化博弈论视野中的周礼与暴力——以春秋与东汉为历史切片

The Rites of Zhou and Violence from the Perspective of Evolutionary Game Theory:Illustrations from the Spring and Autumn Period and the Eastern Han Dynasty

西周建立以后,基于宗法的周礼对军事行动合法性的约束曾长期有效,与之对应,《司马法》《六韬》等周礼色彩浓郁的兵法亦强调战争的伦理性质对战争自身胜负的重要影响。但从春秋中晚期开始,周礼对于军事行动的约束作用逐渐衰微,战争中的欺瞒等非伦理行为也日益频繁起来。作为春秋中晚期战争实践学术反思的产物,孙武的《孙子兵法》基本绕开了对于战争伦理性与合法性的讨论,并毫不掩饰地探讨诈谋的使用,最终完成了对基于周礼的西周军事观念的“马基雅维利式转向”。解释这一转向的主要资源将来自演化博弈论。大致而言,周礼在战场上的应用是以基于贵族核心地位的车战为技术载体的,而随着春秋的争霸战争所涉及的地理范围拓展到了不适合车战的中原边缘地区,步兵战法便慢慢淘汰车战,并由此边缘化了贵族的军事—政治地位。而步兵在古典中国语境中的廉价性又降低了每一个普通士兵的博弈权重,由此铺就了通向秦政之路。代秦的两汉虽然在表面上崇周,却已无法恢复周政下的贵族博弈传统。毋宁说,在东汉朝政中进行政争的各种势力——宦官集团、外戚集团与清流集团——都因自身的“祛地域性”而丧失了在必要的博弈缓冲区内长远筹划的能力,而往往本着赢家通吃的妄念而进行不必要的政治冒险。而鼓吹复仇的公羊学又在意识形态上为这种冒险提供了思想助燃剂。汉末大内战的不可避免性,由此便得到了一种基于演化博弈论的说明。

Zhou Li(or the Rites of Zhou), which is based on the patriarchal clan system, had long been valid in defining the legitimacy of military operations since the Western Zhou Dynasty was established. Accordingly, the Zhou-Li-imbuing writings on war strategies like The Methods of the Sima or Six Secret Teachings also paid enough attention to how the justification of a war influences its outcomes. However, from the middle of the Spring and Autumn Period, Zhou-Li-ethics-violating cheating behaviors became more frequent in the battlefields, and such phenomena were theoretically reflected upon in Sun Wu?s Arts of War. Sun Wu, who focused on how to win a real battle, systematically avoided discussing the legitimacy of military operations, and such avoidance dramatically distanced him from the whole Zhou-Li tradition on one hand, made him a 2000-year-aheading forerunner of the Machiavellian political philosophy in the west on the other. An explanation of why such a Machiavellian turn occurred in China so early would appeal to evolutionary game theory. Generally speaking, the application of Zhou Li in the battlefields had to assort to noblemen as the key human resource for chariot-based wars. Nonetheless, as soon as the typical geographical scenarios of inter-vassal-state wars spread from chariot-friendly plains to chariot-unfriendly valleys, mountains or water network areas, infantry-dominant form of wars had to play its core role to guarantee the odds for winning. Consequently, chariot-based military noblemen, along with the Zhou-Li system underlying their military practices, were quickly marginalized in this new form of war. However, the marginalization of chariot-based warriors does not mean the rise of the political status of any individual infantry, since they are too cheap(individually), too many(collectively), and too unfamiliar to each other(inter-subjectively) to form an organized social institution to gain enough advantages vis-à-vis the brutality of a Sun-Wu-alike commander. In this sense, the Sun-style war did predicate the coming of the Qin-style empire, in which little room was left for the political/economic freedom of the ruled. Though the Qin Empire was quickly replaced by the Han Empire, the historical inertia still functioned in the new empire by keeping the Zhou-li imbuing long-term game strategists out of the door of the game. As for instance, in the history of the Eastern Han Dynasty, top game players like the eunuch-group, the consort-kin-group and the Confucian-intellectual-group, due to their lack of experiences of investing limited resources in local areas, did also all lack the intellectual capacities to elude the prisoner-dilemma on an empire-level. Consequently, with the delusion of controlling unlimited resources of the whole empire, they were more inclined to take unnecessary risks in political competitions, which in turn paved the way for a global civil war. In this process, the Gongyang commentaries on Spring and Autumn, which is a core part of Confucian ideology in the Han Empire, did encourage such violence by theoretically justifying revenges.