Yes, we always seem to think like this:
But in history, there was an earth-shattering discussion on causality in philosophy, and its influence has not dissipated yet.
1737, david hume, a 26-year-old Englishman (171-1776) ended his three-year sojourn in France and returned to London. He brought a manuscript, The Theory of Human Nature, which he wrote during his stay in France. As a young folk philosopher (at that time, all people who engaged in philosophy were folk philosophers), he said to the Thames with longing: tremble, European philosophy, I am coming.
As a result, no one bought the book, no one discussed it, and no one was interested. Hume himself said that it was stillborn on the printing press. It was not until more than ten years later that Hume's views were gradually taken seriously.
The theory of human nature is so magnificent that Hume almost had a nervous breakdown when he wrote it. As a philosophical work, the most groundbreaking point of this book is about causality and induction.
Hume said that when you see the sun shining on a stone, it becomes hot. You would say that the sun shines is the cause of the stone's heat, and there is a causal relationship between the two. We have known this for thousands of years. The problem is that the sun shines on us and the stone is hot. So which organ do we use to perceive this causal relationship? Since we can't perceive it, why should we say that there must be something called causality between these two phenomena?
Today, the sun shines on the stone, yesterday, the sun shines on the stone. It used to be like this, and then we said it was the law of cause and effect. Why? How can you guarantee that it will be like this tomorrow, forever? The sun used to rise in the east every day. Will it definitely rise in the East in the future?
Not to mention academia, even ordinary people are saying that the child is not sick, right? Isn't that what we have been thinking for thousands of years? The great Newton (1643- 1727) just died, and the law of universal gravitation accurately predicted the trajectory of celestial bodies. Isn't this a causal relationship? Isn't this a scientific law? What do you suspect? Do you mean that when you get up tomorrow morning, the apples on the tree will not necessarily fall to the ground, but will fly into the air?
Hume replied, I'm sorry, in a sense, yes. I admire the achievements of my compatriot Newton, and we are enjoying the achievements of Newton's theory, but I still want to say that from a philosophical point of view, Newton's law is not necessarily effective, just a possibility, a possibility. We can't infer that Newton's law was established in the past and will be established in the future. We can only say that when the apple leaves the branch tomorrow morning, it will probably fall to the ground.
Is this a wrangling? Are you a philosopher or a sophist?
Hume said, don't worry, of course I am a philosopher and a folk. I have great respect for my knowledge and human knowledge. Knowing is knowing, and not knowing is not knowing. Whether there is a so-called causal relationship between things, precisely, we don't know, because we can't perceive this thing. People tend to think that there is a causal relationship, because this is our psychological need and a habit. Moreover, this causal relationship is not inevitable, but possible.
Why do you say that? Let's look at induction again. We observe that swans in many places are white, so we think all swans are white. This is induction, that's how our knowledge of natural science is acquired, and that's how our so-called law of cause and effect is acquired. However, induction is logically untenable. How to deduce all unknown judgments from some known experiences? All the swans we have seen are white. How can it be inferred that all swans in the future are white? What if there is a black swan (the famous black swan comes from Mr. Hume)? Even if Newton's law succeeds 10 thousand times, it doesn't mean it will succeed next time, it only means it may succeed.
If we admit that what Hume said is correct, then the whole human cognitive system, especially the whole scientific system, will be subverted. The scientific laws we are looking for are nothing more than some psychological habits, and there is no guarantee that they will be effective in the future. Can we still engage in scientific research happily? At first, no one was willing to accept this statement. Everyone thinks that Hume is completely unreasonable, but slowly, the whole European philosophy community understands that Hume has raised an extremely essential question about cognitive theory, which cannot be refuted. In the end, everyone can only choose to ignore it, which will not affect our continued use of Newton's law in the real world.
Only one person thinks this is impossible and must reply to Hume, because Hume not only challenged philosophy, but also subverted the cognitive system of human beings for thousands of years, making science completely untenable. This man is Kant (1724- 1804).
After hearing Hume's point of view for the first time, Kant fell into meditation, and then he meditated for eleven years until the publication of Critique of Pure Reason. The fate of this book is comparable to the theory of human nature, and no one can understand it after publication. Until the book review was published a year later, the interpretation was still wrong.
Kant said that all our past cognition assumed that there was an objective existence and objective laws in the world, and the purpose of our cognition was to understand this objective existence and discover these laws. But it's not true. We can't really understand the objective world. We can only know the part of the world that our innate reason allows us to know.
Our brains are not a blank sheet of paper. We are born with a certain rationality. We have our own operating system, and our perception of those experiences is based on innate rationality. For example, Hume said that we can only perceive the sun before the stone is hot, so this beginning and end is the perception of time, which is innate. Although Hume doesn't think that the apple will fall to the ground the next day, he also admits that the tree is higher than the ground, which is the space, and the concept of this space is innate.
For example (Kant didn't make an analogy, he used a book to prove it), each of us wears a pair of colored glasses to see the world, and we can only perceive and know the world presented in this glasses. As for what the world looks like and what it looks like without glasses, I'm sorry, we don't know, the objective world is unknown.
What is this so-called congenital reason, that glasses, that operating system? Kant gave space and time and twelve categories, and causality is one of them. Each of us uses these innate cognitive abilities to recognize the world, which is man-made natural legislation. It is not a question of whether our cognition conforms to the objective world, but whether our cognition necessarily conforms to our rationality.
Everything has a cause, and there is a causal relationship. As long as the conditions remain unchanged, the cause can of course be deduced, and there is a causal law. This is our innate rationality. Whether it exists in the objective world is not important. Anyway, we can only know the world that our innate reason can know. Thus, Hume's problem was solved perfectly, and in this world, people can study science happily again!
Some people say that you Kant said that there are twelve categories, and there are. How can you prove it? Well, this needs a book "Critique of Pure Reason" to elaborate.
Before Kant, there were two schools of philosophy, materialism and idealism. Since Kant, no one has adhered to materialism in mainstream philosophy (students who don't know can go to the wall). The world is idealistic, and we can only know what we can know. The law was invented by ourselves. As for the objective part, we can't know, and we can't know.
Kant is the greatest philosopher in modern times, and his philosophy is a reservoir. All the old philosophies gathered here before, and then all the new philosophies flowed out of him. Hawking said that although the development of modern physics, especially quantum mechanics, has greatly subverted the cognition of people including philosophers, Kant is not out of date.
The next hundred years will be a century of great scientific development. Classical mechanics, electromagnetism, chemistry, medicine and modern physics, the achievements of the whole industrial revolution are based on scientific laws, that is, the process from A to B is repeated constantly. It wasn't until karl popper (1902- 1994) moved out this question again, saying, wait, learning science is not so pleasant.
Popper said, I totally agree with Kant's statement about innate reason. We can only know the world that our reason allows us to know. I also agree that everything happens for a reason. However, I am on Hume's side about the inevitability of this causal relationship and this causal law. I don't think Kant completely solved Hume's problem.
We can accept the truth that A is B, but you have observed A before B for 10,000 times, and you can't use our innate rationality to infer that A will be followed by B next time. Kant's answer to this question is not thorough enough. Isn't Newton's law subverted by relativity? The problem of causality is essentially the same as induction.
Induction is to deduce the unknown from the known, the infinite from the finite, and the full-name proposition from the special proposition-some S are P, and all S are P? A farmer keeps a chicken and feeds it every day. The chicken came to the conclusion that the farmer came to feed it every day until he killed it the day before Thanksgiving. The chicken wondered to the death why induction worked (this example came from Russell).
In order to prove a theory, there are only two kinds of reasoning methods we can use: induction and deduction. First, we can't prove induction by induction. This is a circular argument. Then, if it is deductive proof induction, its demonstration process is like this:
But the question is, isn't the premise of this deduction that induction must be correct? Or circular argument.
Therefore, logically, induction cannot be proved, Hume's problem still exists, and the so-called causal relationship is still not inevitable, only probable.
So what should we do?
Popper said that scientific theories cannot be confirmed from a logical point of view. Even if Newton's law and relativity are established thousands of times, it cannot be inferred that the next one will be established. Hume is right in this respect. But scientific theories can be falsified. We can't prove that all swans are white, but as long as there is a black swan, we can say that all swans are white. As long as we don't find the black swan, we can still believe that the swan is white.
What is science? Science is a hypothesis and theory put forward by human beings to explain and predict the world. It can't be completely confirmed, but it can be observed, repeated, experimented and falsified. Before this theory is falsified, if it is effective, we choose to believe it. Even if it is falsified, we can still choose to continue to use it under limited conditions and scope, just like Newton's law. So the truth is that the laws of this world are all subjective, all made up by human beings themselves, all of which are not inevitable, but all of which are conditional. There is no eternal objective law in this world, only practicality and iteration, which is falsificationism.
Some people say, Mr. Pope, what you said is so good that we are suddenly enlightened and the cognitive problems of human beings have been solved; But can your falsificationism be falsified?
After a silence, Popper whispered, "Get out!" .