Immanuel Kant 1724 was born in Konigsberg, the capital of East Prussia (present-day Kaliningrad, Russia) to a devout Protestant family, and his father was a saddle maker. From 16 to 2 1, he studied philosophy at the University of Konigsberg. After graduation, he worked as a tutor in an earl's house for four years. Later, he was a lecturer at 15, a professor at 16, and the president of 1 1 at the University of Konigsberg. He resigned as a teacher at the age of 73 and died at the age of 80.1Feb. 804. It is said that Kant was as thin as a mummy when he died.

We are all familiar with the words engraved on Kant's tombstone: "There are two things. The deeper and longer I think about them, the more surprises and awe they arouse in my mind. These are the starry sky above my head and the moral law in my heart. " This passage comes from the last chapter of Critique of Practical Reason, one of the three major criticisms. This passage can be used as the gist of people's understanding of Kant's philosophy, because it tells us two major themes of Kant's philosophy-nature and freedom.

In Kant's era, the main philosophical problem lies in the dispute between rationalism represented by Descartes and empiricism represented by Locke and Hume about the universality and inevitability of scientific knowledge. Rousseau, who had a great influence on Kant, highlighted the contradiction among nature, freedom, civilization and progress in a fierce way, and prompted the Enlightenment, which preached the omnipotence of reason, to begin to reflect. Metaphysics, as the core department of philosophy, also exists in name only under the attack of Hume's skepticism and French materialism. Kant tried to bridge these two views. He not only criticized metaphysics and put forward the limitations of human epistemology, but also produced a metaphysical feeling in order to overcome a nihilism that existed at that time.

In Kant's epoch-making book Critique of Pure Reason, Kant reduced the philosophical problems to three questions-what can I know, what should I do and what can I expect.

The so-called "Copernican Revolution" in epistemology is aimed at the subject-object relationship of traditional epistemology. According to Kant's pre-epistemology, man is the subject of knowledge, the object of human knowledge is the exterior of man, and the subject and object are opposite. With the development of science, people's ability to understand and conquer the outside world has been continuously improved, and human rationality advocated since the Enlightenment has gradually been placed in a condescending and omnipotent position. Rationality and science have been mythologized as the new will of God, while human beings are threatened by value nihilism. Kant foresaw that the development of scientific rationality could not prove the value and dignity of human beings. When the world is shrouded in inevitability, human beings lose their freedom.

Kant's "Copernican Revolution" reversed the relationship between knowledge and object, and the object no longer revolved around the subject, but the subject revolved around the object. On this basis, Kant divides rationality into practical rationality and theoretical rationality, the latter refers to scientific rationality, and the former is the innate moral law of human beings. The purpose of this distinction is to limit the cognitive ability of reason and highlight the priority of practical reason, thus leaving a place for people's moral beliefs. Because only by transferring the object of metaphysics from the cognitive field of theoretical rationality to the moral field of practical rationality can freedom be realized by morality. In Kant's view, man is a limited rational being. He is both a natural being and a rational being, and is influenced by the laws of nature and rationality.

Kant also disagrees with empiricists. He believes that knowledge is acquired by human beings through senses and reason. Experience is a necessary condition for knowledge, but it is by no means the only way. Transforming experience into knowledge requires rationality (rationality here refers to an ability of talent, which Kant calls a category).

Sturm und drang, who experienced adolescence, established a complete philosophical system of knowledge, action and meaning in his middle age. Kant devoted himself to the question of how a reasonable civil society is possible in his later years. Especially after the magnificent French Revolution, Kant saw the urgency of this historical, political and legal issue, so he devoted his energy to the study of legal rights and political philosophy in his later years. The18th century in which Kant lived was a century of frequent wars in Europe, from 170 1 to 17 14, from 1700 to172. Frequent conflicts between countries made Kant realize that the normal state of human history is not peace but war. Therefore, a metaphysical thinking on the improvement and progress of human civilization from war to peace, and pointing out that human development is towards the goal and purpose of permanent peace, has become the ultimate goal of Kant's later years.

In Kant's view, a civil society based on private rights needs a kind of public rights to maintain and guarantee, including constitution, administrative law and international law. Public rights are not only manifested in different political systems, but also in the national rights of a country, thus constituting international law between countries. In On Permanent Peace, which was completed in 1795, Kant put forward the ideal of establishing a world constitutional government and a country with permanent peace. In his view, only when individuals become members of the civil society of the international community can countries overcome the state of war and enter permanent peace, and real civilization-get rid of barbarism and enter the ideal state of freedom and justice through a sound legal system and political system-can be realized. Although it is not easy to achieve permanent peace, Kant believes that the mechanism of nature can finally solve this problem, because it is through the selfish tendency of nature's confrontation with nature that those who are at odds with each other must obey mandatory laws, thus promoting internal and external peace. To put it simply, it means that "nature prepares for war through extreme tension and never slackens off …", and finally realizes the "grand alliance of all ethnic groups". Kant's ideal of world government is not original. Before him, there were Rousseau and Saint Pierre of France, but there is no doubt that Kant's argument has more keen insight and meticulous logic, and it was only initially realized in the 20th century. From 65438 to 0945, many principles in On Permanent Peace were written into the Charter of the United Nations.

From the League of Nations to the United Nations, to the establishment of the European Union and the promulgation of the EU Constitution, people are working towards the ideal state described by this wise old man more than 200 years ago-gradually improving international law; Strengthening the role of the United Nations; Facing some global problems such as hunger, disease, natural disasters and poverty, we should strengthen cooperation and so on. The philosopher Kant is our deepest inspiration.