So, the question of how it is possible is a metaphysical question. We are already very clear about metaphysics here, which refers to a foundation that enables our existing knowledge, or the future knowledge we may possess, to be built on a reliable basis. This reliability is the ability to confirm the conditions, forms, and principles of such knowledge.

So, this kind of knowledge is called metaphysical knowledge, and when discussing philosophy in this way, Kant provided us with a model. Later philosophers continued Kant's approach, as if whenever philosophy is discussed, that is, 'what is possible' becomes a philosophical discourse.

And Wittgenstein also gave a philosophical way of solving problems, I can't find my way out. Chen Jiaying translated this sentence as' I can't find the north '. 'Unable to find a way out' has become a general philosophical problem.

If you say that in the future when writing philosophical articles, we will express philosophy in this way, what kind of way, that is, a way of pointing out that we cannot find a channel, becomes a way of philosophical discussion.

Therefore, conversely, the way philosophy approaches and raises philosophical questions is precisely because we have encountered difficulties in reason. It is only to say that Wittgenstein gave a general form of philosophical discussion in a negative way, while Kant gave a positive way. "How is it possible" gives a positive way, telling us that such philosophy is related to some conditions, forms, and principles.

Therefore, when he distinguishes between innate and acquired knowledge, he first involves one thing: if we want to determine that our knowledge is possible, especially the possibility of a comprehensive judgment of innate knowledge, we need to first analyze what is innate and what is acquired.

Innate knowledge refers to knowledge that is universally necessary and independent of experience, while also serving as a condition for experience. And the day after tomorrow, it is only a rare coincidence, related to sensory experience.

In simple judgment, it is not only independent experience, but also a condition for experience to become experience, which becomes innate knowledge. Only such innate knowledge can play a role in a priori philosophy.

However, being innate is not enough. In addition to innate and acquired judgments, he also provided two types of judgments called analysis and synthesis. Because innate and acquired are assumptions in ontology, while analysis and synthesis are assumptions in epistemology.

In the assumptions of epistemology, regarding analysis and judgment, it expresses a kind of innate knowledge, therefore, it is necessarily universally true and independent of sensory experience, without the need for postnatal proof.

We can see that in analytical judgment, the judgment that the subject contains predicates is called analytical judgment, because analytical judgment is true on its own and does not require experience to verify.

For example, A equals A, and A equals A is an analytical judgment, which is innate. Because A is equal to A, there is no need for anything else to prove it. However, if A is equal to B, it is not a congenital analytical judgment, but a comprehensive judgment. We have added new knowledge in the middle, because when we explain that A will be equal to B, it contains our scientific discovery.

Therefore, in this sense, there is a distinction between innate knowledge analysis judgments and comprehensive judgments. So, for comprehensive judgment, the relationship between the subject and predicate has changed, because in analytical judgment, when A=A, it means that A is A. In this judgment, the relationship between the two does not require postnatal verification, logical deduction, or any experience to judge.

Of course, in this context, we can transform it into, for example, B (A is B), just as he mentioned earlier about analytical judgment, that all objects are extensive, analytical, and innate. Why?

Because all objects have the concept of extension, and predicates with extension are included in the subject. There are subject specific definitions, just as it is said that everyone is dead, 'dead' is defined within the concept of human beings, and therefore, this definition is called analytical.

Therefore, the concept of analysis, when we say A is equal to A or A is A, is only the simplest form of analyzing propositions. However, in reality, it only expresses that the predicate is what comes after it, and it should refer to what the subject already contains. Therefore, analyzing a concept is a defining concept, and analyzing a proposition is a defining judgment, a judgment of defining.

Triangles have three sides and so on, all of which belong to analytical propositions.

However, the comprehensive judgment refers to the position that the subject concept does not include. Therefore, predicates may add content to the subject, so when A is not equal to A, it becomes a comprehensive judgment, because at this point we must explain why A is not equal to A and what it is.

Because at this point, we need to explain that when A equals A, it may become an analytical judgment, but when A is not equal to A, it becomes a comprehensive judgment.

Kant's example is that all objects have weight. This judgment is a comprehensive one because the concept of weight is not necessarily included in objects, and not all objects have weight. Therefore, the statement that all objects have weight is a comprehensive judgment based on our measurement of some objects and the discovery that they have weight, leading to the conclusion that all objects have weight.

It is different from all objects having an 'extension', because what does' extension 'refer to?

Extension refers to occupying space, as all objects exist in time and space. Therefore, when there is an extension, it means that it is in space. Therefore, the concept of having space and extension includes the essence of an object, but weight may not necessarily be present.

Some objects may not have weight, for example, we want to ask what the weight of air is, so weight is not a necessary attribute of objects. So, in this sense, of course, Kant understands it this way, but if we look at modern physics, this proposition has become an analytical proposition again, because according to modern physics, anything that exists on Earth has weight because it has the effect of Earth's gravity.

So, it should all have weight, which comes from the force of gravity. In outer space, the concept of weight does not exist in the universe because this weight is related to the Earth's gravity.

This is about Kant's distinction between synthesis and analysis.

Therefore, based on Kant's ideas of innate nurture and analytical synthesis, we can create a simple chart to illustrate the relationship between them. For a type of knowledge, if it is innate knowledge, it is also an analytical judgment, which becomes innate analysis.

What is innate analysis? It means A equals A. Therefore, it is a synonymous repetition.

However, don't underestimate this thing. Later, in Hegel, especially before Hegel, Fichte and Schelling extensively discussed the proposition that 'A equals A'.

What problem is being discussed in the proposition that A equals A?

The discussion is about identity. The concept of identity is also a core concept in metaphysics. Because metaphysics, all the questions discussed are questioning how something is identical to itself.

You may wonder how this has become a core issue in metaphysics, which is also discussed in traditional metaphysics. Why?

Because all metaphysicians, when defining everything as an essence and pursuing the ultimate basis for the existence behind things, are actually trying to equate the existence of a thing itself with the "essence" defined by it.

For example, attributing everything to 'existence', such as attributing everything to 'matter'. If we attribute everything to 'matter', the concept of 'matter' is abstract from all concrete things. But because it is an abstract feature from 'all things', it should become the' concrete feature 'of every thing we talk about.

Just like, there are men and women in the world, and Beidou is for men. When I said Beidou is about men, I had already categorized my masculine traits as an abstract feature, but this abstract feature of men also belongs to my own characteristics.

Therefore, when we say that Beidou is a man, it is equivalent to saying that men are men, and it is equivalent to abstracting my characteristic as an abstract feature. When compared with the general characteristic of men, it becomes "identical to itself". So, the concept of 'the same' is always something that is identical to itself, it is never something that is identical to anything else.

If Beidou were a woman, you would be very strange. You will say, even though you see yourself as a man, how could you say you are a woman? Then you will have doubts. According to maintaining Genstein's statement, this is the philosophical problem at this point.

When you say he's not a man, when you say a person who was originally a man is not a man but a woman, this philosophy comes out. Why?

Because we need to discuss why you say he is a woman, then there is philosophy.