本文將意識形態概念置於思想與知識型構變遷的脈絡之中，在認識論的層次上闡明，語言問題如何制約德拉西的觀念學與馬克思的意識形態理論，以及康德所開啟的批判哲學對意識形態議題的影響。這三者將問題意識分別建立在「觀念」（德拉西）、「主體」（康德）及「現實」（馬克思）的架構之上，正好代表了西方知識體系如何從古典進入現代並穿越現代的歷程。德拉西雖然將觀念學建立在語言的基礎之上，可是他卻視語言是一種透明性的存在，將語言等同於觀念，這種前現代模式的語言觀完全無法支撐他所企圖建立的學科。取而代之的康德批判哲學，雖然克服了古典時期認識論的限制，開啟了現代知識體系，可是其問題意識與語言完全無關，基本上是建立在一個先驗主體的架構之上。不僅導致自我既是認識的主體，同時又是認識的對象，使現代的知識體系立足在一個悖論的與不穩定的地基之上，並且遮蔽了語言與意識形態的關係。馬克思顛倒了康德以主體作為認識基點的模式，他從現實的勞動分工的議題架構中，導引出了意識形態的概念。他雖然認識到語言對意識形態的重要性，然而受制於其時代有關語言知識的限制，無法深入問題的核心，造成其意識形態理論中存在著一個結構性的矛盾。雖然他在後期討論商品拜物教時，將商品比擬為語言，觸及了此一問題。日後語言的問題像幽靈般糾纏著馬克思主義者或非馬克思主義者的意識形態理論。最後，本文進一步指出，語言非但是構成意識形態的前提條件，同時也是進入象徵的維度與無意識領域的門徑，這二個面向不僅擴展與加深了語言與意識形態關係的內涵，也為理解意識形態的運作機制提供了另類可能性。

This paper proposes to explore, on the epistemological level, how the problem of language restricts de Tracy's Ideology and Marx's concept of ideology, and how Kant's Critical philosophy influences upon the development of this issue. These three problematics, based separately on the idea (de Tracy), the subject (Kant) and the reality (Marx), represent the trajectory of the western knowledge from the classical to the modern period. De Tracy establishes Ideology on the basis of language, yet he equates language with idea and treats language as transparency, this pre-modern conception of language can't sustain the science that he wants to create. Although Kant's philosophy overcomes the limits of the classical episteme, his problematic is reposed on a transcendental subject, not on the language. It causes that not only the modern human sciences are based on a contradictory and unstable ground, but also cover the internal relation between the language and ideology. From the division of labor existed in the reality, Marx inverts the problematic of Kant. He understands the importance of language for the theory of ideology, but under the historical constrains, he can't advance to the core of this issue, although he touches this problem in discussing the concept of fetishism. Finally, this paper tries to explain that language is not only the condition of possibilities of the ideology, but the approach of entering the symbolic dimension and the unconscious. These two aspects enlarge and deepen the content of ideology, and provide another way for understanding the mechanism of ideology.