So, on this point, Marx was very accurate. Therefore, Marx never took French philosophers seriously. Although he thought their materialism was often mentioned by us, Marx never regarded French materialism as the peak of materialism. They merely provided us with some resources. However, having resources alone is not enough for thought; conversely, if there is thought, we can seek resources.

In this regard, Montesquieu's statement about reason, that is, his understanding of reason as the relationship between things or the relationship between existences, was merely promoting a common idea in the entire French Enlightenment movement at that time.

This idea was to rebel against the then dominant religious beliefs with rational concepts. Because reason opposes faith, this should be said to be a viewpoint that Montesquieu constantly put forward or repeatedly proved.

Furthermore, from this we can infer Montesquieu's further understanding of this issue. That is to say, why should we establish a society based on the principle of law? If we construct our society in the current way, is it unreasonable or incomplete?

He has his own set of arguments to explain why our society should be structured in accordance with the spirit of the law. Here, he clearly points out that although human beings are rational animals, their rationality itself leads to the possibility of actions that are independent of natural laws.

And this kind of action of natural law, acting independently of itself, precisely violates the requirements of the law itself, that is to say, as Marx later understood it. This reflects that French philosophers truly realized that human beings are driven by so-called subjective initiative. Therefore, humans are agents, humans are active beings, humans are not passive actors, humans are not simple actors. If humans were simple actors, we would be no different from animals.

An animal is simply a moving creature that survives to adapt to its environment, so it will completely change due to the environment. However, human beings, as an animal, are different from others. Because they not only adapt to the influence of the environment, but more importantly, they can also transform their environment, which is something that no other animals can do except humans.

In this sense, human beings, as animals, not only have the biological nature of abiding by the laws of nature, but also possess the natural trait of violating these laws through their own agency and exerting influence.

Marx said that this ability is very good because it precisely reflects the positive significance of subjective initiative. Of course, Marx positively affirmed this in another sense, not on the very line of thought provided by the French philosopher himself.

However, the conditions given by Montesquieu are precisely because, as an active agent, man possesses a certain degree of initiative. Therefore, he often goes against the nature. So, even if they have established their own rules, which are the so-called legal principles, they do not always abide by them.

So, the formulation of laws has been perfected since the ancient Roman era. That is to say, Roman law is regarded as the model for subsequent laws. At that time, we were already human beings and had laws to abide by. However, why do various disputes, wars and conflicts still occur in human society? Why do governments still change?

That is because people always make laws but constantly break them. Therefore, this is the root cause of poor governance among humans.

Indeed, the necessity we just explained is only the necessity of explaining a causal relationship. A causal relationship is when you explain the relationship between cause and effect as necessary.

It is not because these two things themselves have necessity. Among French philosophers, they are more concerned not with that so-called logical necessity. However, the problem lies in that for the entire group of French philosophers, there is no issue with logical necessity, that is, the scientific method that we can verify. For them, that thing has already become science and a part of certain knowledge, so there should be no problem there.

However, the problem lies in that when we apply and extend this set of scientific knowledge with certainty, this way of thinking or this method to human society, and even to all of nature, problems arise.

For, when we merely talk about a logical proposition or an analytical problem, we can simply say that an analytical proposition is necessary because A = A, which is beyond doubt, as it does not contain any new content. Therefore, it must be analytical. When A = B, it is no longer analytical, and thus, it no longer has necessity. Because if there is any necessity in it at all, it is completely derived from A = A.

The difficulty faced by French philosophers lies precisely here. On the one hand, they acknowledge the completeness and accuracy of scientific knowledge and consider it to be universal or necessary knowledge. However, when we apply this knowledge to human society, the question arises as to whether it is also necessary.

So, we usually accept the set of inferences it makes. Without this set of inferences, the concepts of social justice and freedom and equality could not be established.

If the concepts of freedom and equality do not have universal significance, then why do we even talk about them?

Then, this theory is merely a facade concocted by bourgeois ideologues to lull the masses, just as Marx pointed out. We can indeed acknowledge the criticism Marx leveled at this theory proposed by French bourgeois thinkers, but in reality, the situation is not entirely as he described.

That is to say, the French thinkers did not merely offer a set of methods that could only be used by the bourgeoisie. They attempted to make them universal. Even the ideas they put forward about building a state system in a so-called way of separation of powers and democratization, in their view, were universal laws for humanity.

It is not the case that it can only be applied in a certain type of country, for instance, only in a constitutional monarchy or a democratic country. On the contrary, they believe that this is a universal approach that all countries should adopt once they enter the modern society. This is also an important theoretical reason why contemporary America is so eager to promote what it considers democratic and free ideas throughout the world.

They believed it to be universal, not thinking that only the United States or other Western countries should abide by it while Eastern countries need not. They did not hold such a view. Therefore, the Enlightenment thinkers of France provided a direction for thought and for later generations.

It is to extend the universal knowledge that can be established in science to all aspects of human society.

This promotion is probably a bit over the top again, it's an excessive application of a scientific approach. However, if they don't overdo it, they will encounter another difficulty, which is that if an idea has its true power, if a philosophy can have its own value, the prerequisite is that it must have universality.

The value of philosophy lies in its universal applicability.

If a philosophy's value is confined to a narrow field, it will not become a philosophy that is widely accepted. Therefore, why do almost all scientists, including some social scientists, when they study all phenomena in human society and even in nature, always hope to transform the conclusions they draw from individual phenomena into abstract concepts of universal significance? Only the thoughts formed on the basis of these abstract concepts are valuable thoughts.

Otherwise, it would become a one-sided view. Then you could only explain the problems you are facing at the moment. That would be what we call the theory that "a cat is a good cat as long as it catches mice". But a cat is not just for catching mice. So, is a cat that doesn't catch mice not a good cat?

It doesn't catch mice, but it can still be a good cat. The key lies in how you evaluate a good cat. This change in thinking pattern shows that we usually think we can only view things in one form. In fact, if you look at it from a different perspective, its meaning will be completely different.

So, when French philosophers, when they face the difficulty that is to want to extend the universal principles of science to our society and become overly excessive in doing so, the result is that in order to avoid such a difficulty, they fall into another one.

That is, if an idea is to have universality, it must become an abstract concept. This is another difficulty, that is, French philosophers are struggling between two difficulties.

So, why did Rousseau become so dispirited in his thinking?

It can be said that from Montesquieu to Diderot, such thinkers hardly had a philosopher's individual character like Rousseau. All of them were extremely optimistic, bold and full of hope for the future. They were never overwhelmed by any specific difficulties. They never regarded life as a danger. On the contrary, they found great joy in it. They believed that through our personal efforts, we could make the world remember our ideas.