Heidegger is one of the founders and main representatives of existential philosophy. He quoted this passage from Plato in his book "Being and Time": "When you use the word 'being' you are obviously already familiar with what it means, but we also believed that we understood it, But now we are at a loss.” Then he said that Plato pointed out that the meaning of "being" that everyone was familiar with was actually not understood by anyone. This problem has not been solved until today, 2000 years later, and he is here to re-raise and solve this problem of the meaning of "in". Heidegger elaborates on the meaning of "being" as follows:

The nature of already having. In other words, first of all, there must be "being" before there is a "being"; it is absolutely impossible to not "be" at all, and then there is a "being".

To solve the problem of "being", we must trace it back to a kind of "being". The "being" of this kind of "being" is already clear when it is not clear what it is.

Heidegger believes that only "I" is this kind of "being", and only "I" has become clear when its "being" is still unclear. Therefore, he believes that "I" is "being" and "being" is "I". Going on, Heidegger talks about the "being" of "I" as the world.

Here, the core of Heidegger’s thought is: the individual is the existence of the world. Of all mammals, only humans have the ability to be aware of their existence. They do not exist as selves in relation to the external world, nor as entities interacting with other things in the world. Human beings exist through the existence of the world, and the world exists due to the existence of human beings. Heidegger also believed that human beings are in contradiction, they anticipate inevitable death, and death leads to painful and terrifying experiences. They have to accept that death is inevitable, and then everything ceases to exist. Our existence is neither of our own making nor of our choice. Existence is imposed on us and will continue until we die.

Heidegger’s philosophy has a strong influence on modern existential psychology, especially on the psychology of L. Binswanger. He regarded Heidegger's concept of the existence of the world as the basic principle of existential psychology. His existential thoughts also had a great inspiring effect on the future development of psychotherapy. After getting Brentano's paper "On the Multiple Meanings of "Being" in Aristotle", Heidegger said: "I started my first clumsy attempt in philosophy." The first opening Regarding Heidegger's questioning of existence, Leibniz once lamented: "How shocking it is to be aware of one's own existence!" Heidegger was obviously shocked by philosophical questions, and insisted that philosophy is the question of existence. The question of "existence".

While at the University of Freiburg, Heidegger published papers in some philosophy magazines ("Scholar") and had close contacts with famous teachers at the time, such as Schneider and Rickert. When he graduated, Heidegger I considered specializing in mathematics to obtain teaching qualifications and specializing in philosophy to stay in school and work or continue philosophy. In the end, I entered the philosophy department and turned to Husserl.

When I was in college, I was greatly influenced by Husserl's "Logical Investigations" and said that this book had extraordinary charm. Although it was difficult to read, I never left this book. In 1912, he published "New Explorations in Logic" in "Literary Prospects for Catholic Germany". This article chose the problem of mentalism that had been overcome by Husserl as its theme, which shows the profound influence of Husserl on it. After successfully obtaining the "best" result in "The Psychological Doctrine of Judgment" directed by Schneider, he successfully obtained his doctorate.

Later, in 1915, when World War I broke out, he obtained the teaching qualification and wrote the qualification paper "Deng Scotus's Theory of Category and Meaning". In his paper, Heidegger borrowed Scotus’s language to discuss “categories” in the sense that he examined various object fields and the basic structures or frameworks that constitute “forms of reality.” While working as an unpaid lecturer, I met Husserl. The latter admired Hai's talent and called him a "phenomenological prodigy". Before this, Husserl's older friend, Natop Fang at the University of Marburg, had intended to hire Heidegger to give lectures at his school, but he Due to various reasons, it has never been possible.

In 2020, there was a plan to recruit Heidegger as a non-staff professor. I met Jaspers at Husserl’s birthday party in early April. When the University of Marburg officially planned to recruit him in February 2022, the result was still not realized. In September, Heidelberg After a week of discussions with Jaspers in Jaspers' private home, he compiled "Aristotle's Phenomenological Interpretation" (i.e., the "Natop Manuscript") in mid-October and sent it to the University of Marburg and Columbia. Tingen University, these developments were very important and marked the methodological preparation for Being and Time.

In 1923, a mountain hut was built in Tottenau Castle and served as the main writing place. In 1927, after publishing "The Concept of Time" in 1924, the first part of "Being and Time" came out Since then, Heidegger has become famous and has undoubtedly become the number one figure in German philosophy. "Being and Time" was not really mature when it was formed. If there was no external pressure, Heidegger might have postponed the publication of this book. There are also many sloppy and hasty aspects in the book.

Many issues throughout Heidegger’s thought process are concentrated here, including “authentic state and non-authentic state”, “logic and judgment”, “truth formation” and “experience prior to theoretical knowledge”. "Factual life", "the way of existence of Dasein", "the question of time", etc.

Heidegger begins by reiterating the necessity of questioning the "meaning of existence", since "existence" itself is something that transcends all species. It is the most common concept of relation. Everyone seems to understand it, but its meaning is indeed hidden in the darkness. Starting from Plato, people have erroneously equated existence with all beings. Heidegger believes that Western philosophy has gone further and further in this error. The book discusses the issues of Dasein, the world, and time in detail. Generally speaking, the book is divided into parts of Dasein and the world, Dasein and time, and the expansion of Dasein.

In the preparatory narrative in the book, anthropology, psychology and biology are planned, and preparations for survivalism are carried out.

And raised the basic question of Dasein (Dasein), "Dasein is always my existence." Dasein refers to the existence of human beings. In order to avoid the dominance of the subject and the objectification of human beings in traditional metaphysics, Heidegger (Cartesian thinking) and choose this word.

Immediately afterwards, he proposed that Dasein is always "IN-der-welt-sein" (being in the world), and discussed the world and all aspects of the world in detail. The world is not a simple collection of objects, it is not an object that can be directly observed by us. We always belong to the world. It also discussed Descartes' ontology, proposed tools and beings in the world, and discussed in detail people's grasp of the tools of objects.

The unfolding style of Dasein is divided into: emotion, speech, and understanding. Dasein is thrown into the world, and it always sinks into the world without authenticity, and exists with others in the sinking. Based on this, Heidegger proposed the concept of people. We always exist with other people, and in this Participate in everything of the public together, and then lose oneself and be left to manage oneself, and then it is the form of sinking: gossip, curiosity, and ambiguity.

Although Dasein always exists inauthentically, Heidegger proposed an emotion of "fear" that makes authenticity possible. Fear has no specific object, but is a manifestation of human finitude. The basic existence of Dasein is - worry. When fear strikes, Dasein leaves the body and becomes aware of its own finitude. In fear, it is nothing and is in the land of nothing. Dasein is afraid of sinking and has its true state. Fear enables Dasein to see its ultimate end - death. Heidegger discussed the concept of death in detail, which is the expiration of time and cannot be experienced. He made Dasein plan itself-to live towards death. At this time, "conscience" appeared to call Dasein. Dasein sees in this conscience the existential structure of authentic being.

In the last part of the book, the issue of time is discussed, the traditional counting of time is criticized, and the living state of Dasein is discussed in conjunction with temporality, and the main manifestation of the confusing concept "people are time" is derived. The discussion of temporality such as understanding and sinking also leads to Heidegger’s concept of history.

In general, this book uses the presence of people to explore the various meanings of existence. The various conclusions analyzed thereafter lead to the "clear place" of existence, where the subject of existence is grasped, and the light and shadow are crisscrossed. The existence field of existence is existence itself, which makes the conditions of things and being exist, and things and being are what they are, returning to themselves. But the exploration of existence itself does not end there.

Due to various reasons, or perhaps because of his ideological breakdown, Heidegger decided not to write the second part of the book. Later thoughts are basically supplements to "Existence and Time", mainly found in "Introduction to Metaphysics", "The Origin of Works of Art", "Time and Existence", "The Nature of Ground", "The Nature of Truth", etc.

Heidegger had a high level of accomplishment in science, and could have high-level scientific dialogues with Heisenberg. Later, he also put forward his own criticism of science and technology: "The Age of World Images" and "Questioning Technology". When Heidegger later declared the end of philosophy, this was naturally due to his profound research on the history of philosophy. Later, his complete works have been published in more than 80 volumes. They are undoubtedly treasures in the intellectual world. He used his thoughts to prove his whole life. Using "Dasein" and "Ereignis" to explain Chinese thought: Mou Zongsan, a neo-Confucian, Kantianized Chinese philosophy and established "Yuanjiao". Later, scholars Heideggerized Chinese philosophy and used "Dasein" and "Ereignis" to explain Chinese thought. For example; Zhang Xianglong's "Heidegger's Thoughts and the Way of Heaven in China" and Lai Xianzong's "Taoist Zen and Heidegger's Negotiations".

Scholars have also used Heidegger’s philosophy to construct the theory of Chinese ontological hermeneutics, with the goal of constructing China’s “First Philosophy”. In Aristotle, first philosophy refers to the study of the highest being (the immovable mover or God) in theology, or to the study of existence as existence in ontology (ontology).

Theology is called the first philosophy because its research objects are higher than physical existence; while the study of the latter is the matter of the second philosophy. Ontology is the first philosophy because it studies. The principles, laws which all other branches of science acquiesce to, and which study the whole world of existence, are first causes in this (i.e. ontological) sense. For Husserl, First Philosophy acquires its universal significance. The methodology and theory of First Philosophy is the foundation of all other philosophical disciplines. For example, Lai Xianzong tried to use Heidegger's philosophy to construct the ideological system of Buddhist Onto-Hermeneutik.