Kant

康德在《純粹理性批判》中有一段話值得我們時時警剔：
“Thus all human cognition begins with intuitions, proceeds from there to concepts, and ends with ideas. This cognition does indeed have-with regard to all three of these elements-a priori sources of cognition that seem at first glance to defy the bounds of all experience. Yet a completed cri tique convinces us that all our reason in its speculative use can never-with these elements-get beyond the realm of possible experience. And the cri tique convinces us that the proper vocation of this highest cognitive power is to employ all the methods and principles of reason solely for tracing nature to its innermost core according to all possible principles of unity-the foremost of which is the unity of purposes-but never to soar beyond nature’s boundary, since for us there is nothing but empty space outside it. The critical investigation-as carried out in the Transcendental Analytic-of all propositions that can expand our cognition beyond actual experience has, to be sure, sufficiently convinced us that these propositions can never lead to anything more than a possible experience. And if we were not distrust full of even the clearest abstract and general doctrines, and if charming and plausible prospects did not entice us to cast off those doctrines’ con straint, then we could indeed have been spared the laborious interrogation of all the dialectical witnesses that a transcendent reason brings for ward on behalf of its claims. For even beforehand we knew with complete certainty that all allegation of reason, although perhaps honestly meant, must be absolutely null, because it concerns information that no human being can ever acquire. Yet there is no end of the talking unless one un covers the true cause of the illusion that can trick even the most reason able person. Moreover, resolving all our transcendent cognition into its el ements (as a study of our inner nature) is in itself of no slight value; but for the philosopher it is even a duty. Hence not only was there a need to investigate comprehensively this entire working of speculative reason-idle though it is–down to its primary sources. But since the dialectical illusion is here not only deceptive in the judgment but is also enticing in the in terest that is here taken in the judgment, and since the illusion is always natural and will remain so for the future, it was advisable for us to draw up comprehensively the proceedings of this trial, as it were, so as to de posit them in the archives of human reason in order to prevent future er rors of a similar kind. ”
( On The Final Aim Of The Natural Dialectic Of Human Reason, Critique of Pure Reason：A702/B730 to A704/B732）
康德提醒了我們：
理性超越感性的運用充其量只是一種規範原則、而不能當作構造原則來運用。沒有感性直覺的內容，概念就是空盪的。客觀知性固然難以確立，理性亦無從確立客觀知識（自然科學、人文科學、社會科學……）。若然錯將規範原則當構造原則來運用，則產生理性的暴虐虚妄。我們須時時予以警剔，理性與知性的分際；對理性予以批判、免理性越界、犯下過失……
……李淳玲：論學統