Therefore, the existence of the "thing in itself" as a hypothetical existence has inevitability rather than being presented by chance. So, this relationship is already very clear, but when it comes to grasping the intellectual form in a rational way and presenting it to us in a free discussion, there is a slight gap between it and the object itself. The relationship between them is not only reflected as a necessary causality.
Although we also consider phenomena or appearances as a result of the thing in itself, we believe that the thing in itself is its cause. But if we consider the thing in itself as the cause of phenomena or appearances, we are once again immersed in discussions about nature, that is, discussions about a priori necessity.
What does rationality need at this moment?
At this point, what is needed is not the inevitable requirement of nature, but the relationship of 'freedom of will'.
So, the concept of freedom is here, freedom of will, the free of will or free will， In fact, it has become an important way for us to grasp practical activities. Freedom of will is a fundamental requirement for us to grasp practice or determine how our practical activities conform to the rational prior principle.
The freedom of will should be a necessary requirement for grasping the prior principles that our rationality can provide. That is to say, without rationality and the freedom of will, all our discussions about freedom would not exist.
Because in Kant's view, there are two types of freedom, one called the freedom of a priori and the other called the freedom of practice. The concept of a priori freedom is actually revealed in Kant's Critique of Pure Reason. He told us that all our discussions about freedom are actually just a priori rationality, or a form of rationality that can provide us with a foundation.
However, simply staying on the basis of a priori freedom, we still cannot determine how our practical rationality is accomplished. For example, prior freedom dictates the necessary causal relationships that arise from all our activities, just like the explanation of necessity given by science today. When we see a phenomenon, we will ask how it happened, and scientists will constantly explore the basis behind it, the "cause".
So, science is not about explaining phenomena, but about discovering the reasons behind them.
If it is only an explanation of the phenomenon, as we have always said, it is just giving a reason, which is called an explanation of the phenomenon. However, he tried to find the fundamental reason behind the phenomenon. This fundamental reason, or questioning the fundamental reason, is actually the basic pre fabricated way of the entire science.
The corresponding freedom is actually determined by the prior causality, that is, by the causal chain brought about by the appearance caused by the thing itself. Therefore, in this sense, prior freedom only determines a necessary relationship of freedom. However, necessity and freedom themselves are contradictory.
Because when you have inevitability, you have no freedom. With necessity, there is no talk of freedom, because having necessity means that everything is innate and determined by some kind of causal relationship.
As we say today, the transition from socialism to communism is an inevitable path, which means that we cannot change it and can only develop in this way, not elsewhere.
So, where does' freedom 'manifest here?
Therefore, we suddenly feel a particularly obvious feature, that is, when Kant talks about the concept of freedom or the concept of a priori freedom, it actually involves a congenital understanding of human beings towards natural things.
This innate understanding dictates that our discussion of causal relationships should be expressed in a priori manner or through a priori intellectual form. Therefore, in this sense, this innate or a priori freedom in cognition cannot determine the ontological freedom of will in human practical activities.
Freedom of will is an ontological issue, it is not a matter of cognition, and it has nothing to do with human cognitive activities.
Because it is determined before the process of human cognition, we humans have the ability to freely control our own volitional activities, exercise our rights, or complete our practical activities.
Therefore, such abilities are not related to experiential activities. Therefore, the discussion of practical rationality actually largely determines the ontological significance of human freedom of will, which is ontological rather than epistemological.
So, when we usually understand 'Critique of Practical Reason', we consider it as a human practical activity. For example, the requirements of moral commands, the establishment of an absolute moral code, including the demand for good will, etc., are all regarded as a discussion with epistemological significance.
In fact, on the contrary, Kant's discussion of the Critique of Pure Reason is an epistemological discussion, while the discussion of the freedom of will or free will in the field of practical reason is precisely an ontological discussion.
Only in this way can we understand why Kant has always emphasized the need to establish a moral principle that transcends all experience and is called a priori. And this moral principle not only transcends experience, but also, in a decisive sense, determines the possibilities of human experiential activities.
This regulation means that when we want to engage in a certain activity or practice, we are determined by our free will, not by any external experiential environment.
For example, when a big fire is burning and someone is in danger, you can decide from your physiological abilities that you can go and save them. For example, you can extinguish a fire, and your physical behavior is biologically determined. Your physical activity is determined in a physiological sense. You can search for things and find ways to extinguish fires, all of which are determined in a physiological sense.
However, whether or not you engage in such physiological activities is not determined by physiological causal relationships. He is determined by your volitional activity. So, the act of sacrificing oneself to save others is not simply epistemological, nor is it determined by a simple causal relationship in a decisive sense. It should be determined by a certain ontological understanding of free will that has already formed before all of our actions.
So, on this premise, all our practical activities are precisely based on such a priori freedom, but at the same time, it is not just a priori freedom, it is the freedom of practice. From this, we can explain the true significance of Kant's Critique of Practical Reason?
So, the true meaning of 'Critique of Practical Reason' is not to provide us with a few moral principles that we can follow and implement, but to provide us with a priori form that constitutes such moral principles.
In this sense, by understanding Kant's Critique of Practical Reason, we can easily grasp the third part of Kant's philosophy. He previously mentioned that the third part is a reflection on religious metaphysics, that is, a reflection on what we hope for. "What we can hope for" is a discussion of religious metaphysics.
However, later Kant transformed this problem into another one, that is, after he wrote "Critique of Practical Reason", he considered that when we can truly experience the transition from nature to freedom and grasp the understanding of reason towards phenomena in the way of practical freedom.
So we actually face a bigger problem, which is how to deal with the relationship between the thing in itself and the phenomenon, that is, how to determine the freedom of will. There is a huge contrast in dealing with the causality between the thing in itself and the phenomenon. This contrast is reflected in the Critique of Pure Reason, which can effectively use our human rational ability to deal with intelligence and the causal relationship between the thing in itself and the phenomenon. However, in the field of freedom, there is no such causal relationship.
Because if there is a causal relationship, it indicates that freedom does not exist. If there is freedom, there is no causality, and if there is causality, there is no freedom. Therefore, in the practical field, it faces a great dilemma. On the one hand, to the right of its balance is a discussion about nature, and we can understand some statements about nature; On the left side of the balance, it is a discussion about freedom, and we can understand the corresponding conditions and principles of practical activity ability.
When both of these are determined, we suddenly realize that there is a contradiction between them, between what is inevitable and what is free. Naturally, it is an inevitable activity, and freedom is indeed in conflict with necessity. If there is necessity, there can be no freedom, and if there is freedom, there can be no necessity.
Therefore, at this point, Kant must resolve this contradiction, otherwise his entire philosophy will fall into a predicament, otherwise his philosophy cannot justify itself.
That is to say, logically speaking, you cannot establish it. On the one hand, you emphasize the necessary conditions, and on the other hand, you emphasize the limits of rational freedom. What is the relationship between the two?
When Kant was solving this problem, he faced a contradiction himself, so what he had to solve at this point was this question - how to freely relate to the existence of the 'thing in itself'?
