當代一些西方學者如Chad Hansen（陳漢生）認為：先秦漢語的語法與西 方的語法有本質上的不同。例如中國古代語言沒有類似西方的具有that-構造 （that-construction）的主從複句。由於這種主從複句是構成西方語言哲學中所 謂命題態度（propositional attitudes）的表達語式，故Hansen 認為：缺少這種 表達語式，中國古代的思想家便不太可能引發出類似西方哲學中的語句性信 念和語意真理的思想，而只能以名或一串名之組合式來表達語詞性信念及實 用真理的思想。 雖然先秦漢語沒有 that-構造的語句，但這並非漢語特有的現象。拉丁語 和古英語也沒有這種語句。現代英語中具有that-構造的語句乃是中古英語經 過語法化過程才逐漸產生的（由指示詞之實詞虛化為補語引導詞之語法功能 詞）。在未經語法化之前，要表達that-construction 的語句所能表達的命題態 度，古代英語使用一種並列結構的複句來表達，二者的表達功能基本上是相 若的。在先秦漢語中，也有類似這種功能上等價的語法構造。 本文的目的，主要是從先秦語料中提出一些明確的論據，以論證中國古 代思想家亦有足夠的語言工具以表達他們的抽象性思想，包括有關命題態度 和語意真理的思想及邏輯推理。

Some contemporary Western scholars such as Chad Hansen maintain that there are essential differences between the syntax of pre-Qin Chinese and that of Western languages. For example, subordinate compound sentences formed using the that-construction do not exist in ancient Chinese. Since this kind of construction allows the expression of what are referred to in the Western philosophy of language as “propositional attitudes” (“I believe that p” or “I know that q”), Hansen thinks that, without this kind of expression, ancient Chinese thinkers were probably unable to form similar sentences that express sentential beliefs and semantic truth as exist in Western philosophy; instead, they could only express term-beliefs and pragmatic truth by using a combination of names or series of names. Although the pre-Qin Chinese language lacks an equivalent to the that-construction, this phenomenon is not restricted to the Chinese language. Neither Latin nor Old English permit this form of sentence construction. The that-construction of Modern English evolved from Middle English via a process of grammaticalization (i.e., from demonstrative as referring term to complementizer as functional word). Before grammaticalization, to express the propositional attitudes just like those expressed by that-sentences in Modern English, Old English used a kind of compound sentence with paratactic structure. Sentences of both constructions are functionally equivalent in expressing propositional attitudes. In pre-Qin Chinese, there exists a similar syntactical construction that is functionally equivalent to the that-construction. The main aim of this paper is to provide clear evidence from the pre-Qin text corpus to show that ancient Chinese thinkers had sufficient linguistic tools to express abstract ideas, including propositional attitudes, semantic truth and logical reasoning.