If our knowledge is illusion, then does scientific research have meaning? Yes. Scientific meaning does not come from objectivity, but from usefulness or practica- lity.

I am hungry now, I want to eat crabs. I want to know if crabs are poisonous. Popper told us: No matter what method you use, you can not prove crabs are non-toxic? Even if you have taken 10 bites, you can't guarantee that the 11th bite is non-toxic. You can not even prove rice non-toxic. So what should you do? Starve to death? This misunderstanding turned Popper's theory into a fasting theory. The responsibility of scientists is not to be miserable, not to sigh, and it is the responsibility of scientists to find a way out for humanity. Although Popper's conclusion is of great theoretical significance, what people need is more of a proof theory. If there is no absolutely confirmed theory, at least we need a relatively proven theory, although the relatively proven theory may cause poisoning, but people also willing to accept, because we do not want to starve to death.

Humans have been using relatively proven theories since ancient times. These theories will have a variety of errors, but they have great practical significance.They can only be perfected gradually and cannot be abandoned. There was hardly any truth in the earliest human hands. There were only some analogical revelations, most of which were wrong. Therefore, human survival ability at that time was very low. But it was such revelations that enabled them to survive and gradually grew stronger. The mistake of Dancy and many western scholars is that they did not consider the question of truth standard from the point of view of practice.

When I said theory is illusion, I did not mean that scientists deliberately falsified. When I said the value of theory comes from practicality, I did not mean instant benefits. The practicality here refers to the promotion of people's interests, including both self-interests and the interests of others, both immediate and long-term interests.