Hume said that all our human knowledge is based on the thinking principle of the law of cause and effect.

Think about it, everyone, the reason why a tree can grow is because it has seeds, and its seeds are the reason for the tree. The reason why a person can be born is because he has a mother, and the mother is the reason why he is born. Let us go deeper, genes are the cause of life. All in all, all your knowledge is built on a causal thought sequence.

The causal relationship you mentioned does not exist in experience, especially in the experience of particular judgments. All human knowledge is constructed based on the causal sequence, which makes Hume deny the basis for the construction of all human knowledge from a purely materialistic and purely empirical perspective. And his denial and questioning are called skeptical philosophy, and they have exact logical basis.

And Hume went on to discuss, he said, then what do we mean by "causation"?

From an empirical perspective, it is just the repeated presentation of a thing in a sequence of time and space, that is, one thing always appears in front of you in time and space, and then another thing happens, so you put this The non-experiential subjective relationship between species is set as "causal relationship".

But this setting is not valid. There is a reason, because you haven't figured out what "time" is and what "space" is. Please note that these things that we take for granted, the so-called "self-evident" things, are exactly what philosophers want to ask. Hume proposed that if what we call "causal connection" does not directly appear in experience, but is expressed as a repeated appearance in space and time, then we must investigate what "time" and "space" are. ". If we cannot investigate this issue clearly and the law of cause and effect does not hold, the entire knowledge structure will collapse. And do "time" and "space" really exist? And what exactly is it? Is it a spiritual phenomenon or an objective phenomenon?

Hume raises doubts, which is very thorough skepticism. But it is built on a very solid logical inquiry. Everyone should know that most of our discussions of cause and effect in daily life are confusing. The law of cause and effect is not established and is not established in experience. For example, in terms of the relationship between time and space, you can express it this way, and even the ancients did express it this way, saying that "the rooster's crow is the reason why the sun rises." The rooster crows every four or five o'clock, and the sun rises after the rooster crows. In terms of time order, the cock crows always comes first. Does this causal relationship hold true? Logically you may find it ridiculous, but in terms of experience it is true.

Russell made a more interesting expression. He said that a chicken farmer raised a group of turkeys. In the eyes of the turkeys, this owner is the reason for their food. He feeds the turkeys on time every day, so the turkeys can believe that the owner is the reason for their food. But it didn't expect that one day the owner would come with a shotgun or a knife. This is why Wittgenstein raised a question, and Hume also raised such a question, saying that the sun rises from the east is just a hypothesis. Because you said that the sun rising from the east is the product of experience, and it is the product of inductive experience, but you can never exhaust the induction. Therefore, the sun rising from the east is a hypothesis, and it is an untenable hypothesis.

We know today that this statement is true. Because the sun will definitely become a red giant in four billion years, it will never rise from the east, it will set head-on until it dissolves the earth. Is that so? So Hume discusses skepticism, which proposes that on an empirical level we can never acquire knowledge, and clearly proves that induction is invalid. It is obvious that all our human real knowledge is based on induction. Therefore, the entire human knowledge building collapsed because Hume's proof was valid. This is called the beginning of agnosticism. Therefore, Hume proposed that previous judgments about the full name of the law of causality, all discussions on the construction of knowledge and even what reality itself is, are all nothing but logical dogmatism.

Hume's argument profoundly shocked the world.