德国古典哲学外延逻辑批判的总线索

A Delineation of the Critique of Extensional Logic by Classical German Philosophers

以三段论为基本模型的形式逻辑推理被指认存在着两项弊端,一是默认大前提中的知识内容先天为真,二是默认从前提到结论的推理形式先天为真。在通常的见解中,人们习惯于分别指出这两者的存在,但并不探讨两者的内在联系,仿佛它们是漠不相关的两个方面。与这种看法相反,我们强调将两项弊端看作同一弊端———脱离内容而进行推理的弊端———的重要性,因为只有这样,才能抓住德国古典哲学逻辑学改造的根本线索。近代哲学创始人与德国古典哲学家进行外延逻辑批判的路径既有差异,又是进入这一线索的钥匙:培根和笛卡尔"绕过"对形式逻辑同一律的反省,单纯进行形式推理大前提批判;从康德到黑格尔则"围绕"形式逻辑同一律,通过引入推理前提内容的产生及真理性考察来实现对两项弊端的共同批判。具体来说,康德的批判途径是在传统逻辑与先验逻辑之间"划界",费希特和谢林是以"自我=自我"扬弃"A=A",黑格尔是以"具体的同一"扬弃"抽象的同一"。培、笛二人与德国哲学家的最终目的一致,即为科学奠基,说明和寻找知识的创生源泉;路径则是不同的,只有后者才更为准确地达到了目的地,进而为马克思《资本论》的创作奠定了逻辑基础。

Formal logic which relies on the basic operation of syllogism is often accused of making two fallacies： first, it presumes the a priori truth of the major premise; second, it presumes the a priori validity of the form of inference. While these two fallacies have been pinpointed separately, the internal connections between them have never been examined. Unlike those who treat these two fallacies as if they were not related to each other, we believe that it is of great importance to draw together these two fallacies and trace their common root to the fallacy of purely formal inference, for only in this way can we get a clue about how the classical German philosophers reformulate the idea of logic. In criticizing the extensional logic the founding fathers of modern philosophy diverge from the classical German philosophers. Yet this is exactly where the key is： Bacon and Descartes focused on the critique of the major premise. In so doing they bypassed the reflections on the law of identity of formal logic. German philosophers from Kant to Hegel took a different path. Their thinking revolves around the law of identity of formal logic, and, thus, brings the two different fallacies under a common scrutiny. Their critique of these two fallacies is grounded in the examination on the genesis and the truth of the contents of the premises. More to the point, Kant＇s approach of the critique is based on the distinction between traditional logic and transcendental logic; Schelling＇s and Fiehte＇s critique involves displacing ＂A=A＂ with ＂self=self;＂ Hegel＇ s is a strategy that relies on the Aufhebung of the abstract identity with concrete identity. Bacon, Descartes and the classical German philosophers share the same final goal--grounding sciences and tracing the real source of the generation of knowledge. Yet their paths diverge, and only the latter can achieve that goal. The classical German philosophers thereby laid a logical foundation for Marx＇s Das Kapital.