I think we should start from the perspective of seeing is believing, or seeing is believing. First, there is an old saying in China that "hearing is false, seeing is believing". In other words, what you hear can't be considered true, but what you see with your own eyes is true. Here we don't discuss whether what we hear is false, only whether what we see is true. The so-called seeing means that the light of external things enters people's eyes and eventually forms an image in their brains, so what they see. Look, first of all, there must be external objective things, and the light emitted by external things should enter people's eyes. The whole space is dark, or you can't see anything with your eyes closed. So what you see is the real objective existence. Seeing is believing is the basic way for human beings to understand the objective world. From the distant universe to microscopic particles, from ancient scientific inventions and discoveries, which one can be believed without seeing? People's naked eye ability is limited, so they created space telescopes, electron microscopes and various observation tools, which greatly expanded people's horizons. Man's understanding of the universe and all scientific achievements are determined by seeing is believing. Since the end of the last century, some people have put forward the view that "seeing is not necessarily believing", and even now it has risen to the height of theory. Some people deny the objective existence that they think does not exist, and it has even become a law. In the objective world, there seems to be a phenomenon that "what you see is not necessarily true", such as seeing the sun rise and set in the west every day, and the sun seems to revolve around the earth; Sitting on a boat in the river, you will see the mountains on both sides retrogressing; Magic show, desert fantasy and mirage, etc. But after analysis, the above phenomenon is also consistent with seeing is believing. Let's watch the magic show first. If the magician catches a live fish from the audience with a pole, what does the audience see? What the audience saw was a live fish churning under the fishing rod. Isn't it true? What the audience sees is real. Of course, the effect of magic is not only to let you see live fish, but also to arouse the audience's association, as if the fish were caught from under the audience's seat. The audience didn't see whether there was any fish under the seat or how the fish was hooked. This is the charm of magic. All magic, one is to have props, and the other is to have superb performance skills. Magic shows only let the audience see the attractive results, but through props and sound and light, the audience can't see or see the whole process clearly. The overall effect of magic is to mobilize the imagination of the audience, and then produce magical effects. What the audience sees is real, whether it's fishing or flying pigeon fish. Fish and flying pigeons are real. Let's talk about the phenomenon that the sun goes around the earth and the mountains on both sides of the river walk backwards. This kind of problem belongs to the visual effect of relative movement, and it is also caused by a person who is relatively static with the observer and has a large space. For example, we put an ant on a globe with a light bulb hanging above it. When we turn the globe, ants' vision is the same as our vision of looking at the sun. When athletes turn ladders or chairs, they don't feel the earth moving around them. Of course, athletes will feel dizzy after dizziness, which is the result of abnormal brain activity and cannot be used as evidence that what they see is not necessarily true. Some people say that what you see on TV and movies is not true. This is a primitive and ignorant view. It is said that when the movie was just shown in the countryside, someone went behind the curtain to see if there was anyone. Now even children don't think there are real people on TV. What we see on the screen is actually a picture, and the visual process of the eyes forms a video effect. If the pictures come from real objects, such as live TV, X-ray fluoroscopy, CT fluoroscopy, B-ultrasound examination, etc., observe the real situation through the screen. Movies and television are extensions of human vision. People can record the scene and watch it later. For example, we often see the scene of President founding ceremony announcing the establishment of People's Republic of China (PRC) on TV. Although more than half a century has passed, isn't its voice and image all true? If the picture comes from computer synthesis, animation, editing and splicing, we can make video plots that don't exist in reality at will. However, what we see is still true, that is, seeing is believing. Nowadays, fake cigarettes, fake wines and fake medicines are prevalent in society, and even there are fake papers, fake academic qualifications and fake cultural relics in the field of science and technology. It makes people feel that what they see is not necessarily true. For example, if you see an ancient painting, it means that there is indeed an ancient painting there. As for whether this painting is the original of a painter of a certain dynasty, it needs to be appraised. If you have the ability to distinguish, you can see at a glance that it is a fake, which means that you really saw a fake painting. If you have no discernment, even if you see the truth, you are not sure whether it is true or not. In real life, there are indeed many things that are difficult to distinguish between true and false. What you see, whether it is true or not, is objective. To judge whether it is true or not, we must first see an unknown, then compare it with the truth, and then draw the conclusion of true or false. Seeing is believing and judging truth and falsehood are two different concepts. You can't tell the truth without seeing it with your own eyes. There are two phenomena that seem to prove the theory that what you see is not necessarily true, that is, desert illusion and mirage. These scenes don't exist in the desert or at sea. Nevertheless, what you see is still true. Modern science explains two phenomena: the scenery on the ground elsewhere is refracted by air with different densities and then seen by people. In this way, although there is no real scenery in the desert or the sea, there are other places. If the desert mirage and mirage are "seeing is not necessarily believing" and their scenery does not exist on the earth at all, then Penglai Wonderland is real. If what you see is not necessarily true, then you can't go home to see your wife and children every day. There are also phenomena related to seeing, such as dreams, hallucinations and seeing images at work. These phenomena cannot be called seeing is believing, because what enters the eyes is not external light, but the physiological process inside the brain, so I won't discuss it here. Second, seeing only some people's eyes can only see part of things, but not all. As far as things are concerned, the eyes can't see the whole; As far as events are concerned, the eyes can't always see. Even with tools. When people look at a machine, a building or a mountain, they can't see everything from one direction. "Looking at the mountain side is the peak, the distance is different, and I don't know what it looks like. I only live in Lushan Mountain. " This poem by Su Shi vividly illustrates this problem. Seeing is believing is only partial, and seeing is believing is not contradictory. Everything you see is an objective existence, but this existence is not the whole, not the whole. This is essentially different from seeing that it is not necessarily true. Part is a kind of existence, and only through part can we find and understand the whole. The white light seen by human eyes actually contains seven colors of light. You can't deny that white is not real. The photosynthesis of the seven colors together is white, which is the characteristic of the existence of matter. Snow is white and ink is black, which is an objective existence seen by human eyes. The fact that the eyes can't see seven colors illustrates the limitations of seeing. In fact, what people can see is only a small part of light. In the process of scientific development and scientific discovery, people's cognitive process is always from simple to complex, from local to whole. When some phenomena you see are incredible and contradict the known scientific laws, although you haven't seen them all, you can't tell their true colors, just like seeing a mirage. Never use "seeing is not necessarily believing" to deny objective existence. What the three eyes can't see is also true, and the eyes can't see the whole, which means there are still places that the eyes can't see objectively. A person closes his eyes and can't see anything, but it doesn't affect the objective existence around him. The world is so big, I'm afraid no one can travel all over the earth; There are so many books that I'm afraid no one can read all the existing books in the world. So much knowledge, what a person or even a scientist has, is probably just a drop in the ocean. For a person, what you see is objective, and what you don't see is objective; What you don't know, others may know; You still have everything except what you haven't seen. Therefore, judging objective existence can never be based on one's own opinions or existing scientific theories. Scientific theory describes the laws of existing things. Although the existing known things exist within the scope of scientific theory, there are still unknown things in the universe, and the unknown things may not necessarily conform to the existing scientific theory. Engels pointed out in Anti-Turin that the universe is infinite and time has no beginning and end. Now humans can see the depths of the universe of 65.438+0.3 billion light years, so we think that the size (radius) of the universe is 65.438+0.3 billion light years. With the progress of science and technology, 20 billion light years will be observed in the future. As long as human beings exist, the scope of observing the universe will never stay at one level. There must be an objective existence outside the universe observed by human beings. What the eyes can't see is also true, which seems to contradict physics. Because physics is based on observational facts and experimental facts, does the eye know objective existence? If we completely separate the process of human cognition and look at the problem one-sidedly, this is indeed the case. If you lock a person in a dark room without light and let him see things around him, he can't see anything and can't provide evidence of what is around him. But when he turns on the light or flashlight or strikes a match, he can see something. It provides evidence of objective existence around. It is both invisible and tangible evidence that human beings can constantly discover new mineral deposits and new cosmic galaxies. If you can't see the objective existence outside, what new discoveries can you make?