预言作为先秦知识系统的组成部分，发挥着重要的社会文化功能。本文试图从《左传》预言的话语形态切入讨论其话语功能，梳理《左传》预言话语形态与功能之间的关系，阐明预言这一话语传统与春秋时期社会思想观念之间的张力，探索预言话语形态与功能嬗变的根本原因。论述主要分为四个章节：

第一章《左传》预言分类是研究的基础工作，本文以预言思维方式的差异将《左传》中的预言分为象征预言与因果预言两大类，象征预言遵循原逻辑的思维，基本话语功能是谕示功能；因果预言遵循因果理性，基本话语功能是解释功能。《左传》中的象征预言包括灾异、星占、卜筮、谣占、梦占、相术六类，因果预言包括察言观礼型预言与推理型预言。

第二章分析《左传》象征预言较之殷商卜辞结构的新变，以及话语结构变化对其谕示功能的影响。象征预言话语结构的新变主要表现在论述空间的开辟和多重占象的设计，多重占象的设计有助于强化象征预言的谕示功能，而论述空间的开辟虽然同样旨在于巫史权威衰落之际争取话语权，却在实质上损害了象征预言的话语权威。

第三章分析《左传》因果预言对预言话语传统的改造，包括占象关注点的转移、论述关键词的更新以及论述权威的嬗变。改造旨在适应春秋时期社会意识形态建设的需求。与象征预言谕示功能受限相反，因果预言解释功能呈现出泛化、简单化的特点。

第四章分析《左传》预言于解释功能退隐之后凸显的修辞功能，并尝试从话语传统与社会理性建设的关系切入，分析《左传》预言话语形态、功能发展变化的根本原因。

As an integral part of the pre-Qin knowledge system, prophecy played an important socio-cultural function. This paper attempts to discuss the discourse function of Zuo Zhuan's prophecy from its discourse form, sort out the relationship between the discourse form and function of Zuo Zhuan's prophecy, clarify the tension between the discourse tradition of prophecy and the social ideology of the Spring and Autumn period, and explore the fundamental reasons for the transmutation of the discourse form and function of prophecy. The exposition is divided into four main chapters.

The first chapter classifies the prophecies in Zuo Zhuan as the basic work of the study. This paper divides the prophecies in Zuo Zhuan into two categories, symbolic prophecies and causal prophecies, based on the differences in the way of thinking about prophecy: symbolic prophecies follow the thinking of proto-logic, and the basic discourse function is oracle function; causal prophecies follow causal rationality, and the basic discourse function is explanation function. The symbolic prophecies in Zuo Zhuan include six types of prophecies: calamity, astrology, divination, rumor, dream, and physiognomy, while the causal prophecies include the ritual prophecy and the reasoning prophecy.

Chapter 2 analyzes the new structure of the symbolic prophecies in Zuo Zhuan compared with the Yin Shang divinatory texts, and the impact of the change in discourse structure on its oracular function. The new changes in the discourse structure of symbolic prophecy are mainly manifested in the opening up of the argumentative space and the design of multiple signs.

Chapter 3 analyzes the transformation of the prophetic discourse tradition by the causal prophecy of Zuo Zhuan, including the shift of the focus of the symbols, the renewal of the argumentative keywords, and the transmutation of the argumentative authority. The transformation aims at adapting to the needs of social ideological construction in the Spring and Autumn period. In contrast to the restricted function of symbolic prophetic oracle, the causal prophetic explanatory function shows a generalized and simplistic character.

Chapter 4 analyzes the rhetorical function of Zuo Zhuan's prophecies that came to the fore after the receding of the explanatory function, and tries to analyze the underlying reasons for the developmental changes in the form and function of Zuo Zhuan's prophetic discourse, starting from the relationship between the discourse tradition and the construction of social rationality.