康德在《純粹理性批判》（1781）中否定「上帝存在」之思辨論證，在《實踐理性批判》（1788）中則轉而提出其道德論證。他於1786年發表的〈何謂「在思考中定向」？〉一文介乎此二書之間，集中呈現出這項思想上的轉折，而構成康德宗教哲學發展中的一個關鍵環節。康德在此文中為理性之超經驗運用揭示一項主觀根據，即「理性底需求」。本文首先闡述康德撰寫此文的思想史背景，接著詳細說明「理性底需求」在其理論性運用與實踐性運用中的功能，最後歸結到康德的「啟蒙」原則。總而言之，康德在此文中完整地闡述了其「道德宗教」的構想，並試圖藉此在「啟蒙」與「狂熱」之間畫出明確的界限。在這個意義下，他實不愧為「啟蒙之子」。

In his ”Critique of Pure Reason” (1781) Kant invalidated all forms of speculative proof of God's existence, but then in his ”Critique of Practical Reason” (1788) he put forward a moral argument for it. Between the publications of these two books, in 1786 he wrote an essay entitled ”What Does It Mean to Orient Oneself in Thinking,” which thematizes this transition and hence constitutes a key link in the development of his philosophy of religion. Here Kant exposes a subjective ground for the trans-empirical use of reason, namely the ”demand of reason.” In this paper I first expound the background for Kant's writing that essay. Then I explain the functions of the ”demand of reason” in its theoretical and practical uses. This paper concludes with a discussion of Kant's conception of ”enlightenment.” In sum, Kant here articulates his conception of ”moral religion” and attempts thereby to draw a clear boundary between ”enlightenment” and ”enthusiasm.” In this sense, he is truly a ”son of enlightenment.”