Immanuel Kant
Kant published a second edition of the "Critique of Pure Reason" ("Kritik der reinen Vernunft") in 1787, heavily revising the first parts of the book. Most of his subsequent work focused on other areas of philosophy. He continued to develop his moral philosophy, notably in 1788's "Critique of Practical Reason" (known as the second "Critique") and 1797's "Metaphysics of Morals". The 1790 "Critique of Judgment" (the third "Critique") applied the Kantian system to aesthetics and teleology. It was in this critique where Kant wrote one of his most popular statements, ""it is absurd to hope that another Newton will arise in the future who will make comprehensible to us the production of a blade of grass according to natural laws"".
The Concept of Anxiety
In 1793, forty-one years before Kierkegaard wrote "The Concept of Anxiety", Immanuel Kant wrote his book "Religion Within the Limits of Reason Alone"; his book elevated reason in the realm of Christianity. Many continental philosophers wrote their books in relation to Kant's ideas. Kierkegaard was familiar with "Book Two" of Kant's book "The Conflict of the Good with the Evil Principle for Sovereignty over Man" and he made a similar study in this book; however, he might call it the conflict of ethics and anxiety for sovereignty over man. Kierkegaard would replace Kant's term "Good" with "Ethics" and his term "Evil" with "Anxiety about the Good". He wrote about the ideal good versus the actual good that a single individual can do in the following way: "Ethics proposes to bring ideality into actuality. On the other hand, it is not the nature of its movement to raise actuality up into ideality. Ethics points to ideality as a task and assumes that every man possesses the requisite conditions. Thus ethics develops a contradiction, inasmuch as it makes clear both the difficulty and the impossibility." He was wondering how any existing human being can make any movement in an ideal world.