As we all know, a deep understanding of the law of world operation mainly depends on rational knowledge, but it is difficult to do it by feeling and experience. The first step to obtain rational knowledge often comes from logical reasoning.

The reliability of logical reasoning mainly lies in the solidity of premises (known conditions (such as axioms), assumptions, etc.) and the preciseness of reasoning process. If the reliability of logical reasoning cannot be satisfied, it is impossible to get a correct conclusion or understanding; If it can be satisfied, can we get a correct understanding?

The answer is not necessarily, because people's understanding based on reliable logical reasoning can only meet self consistency and subjective rationality, but can not ensure that it is consistent with objective facts. Therefore, after getting the understanding, we should test it through demonstration. Only after repeated inspection can we confirm that this understanding is correct. For example, can seawater rice harvest well in saline alkali soil? Although Yuan Longping's team inferred that it might work based on a lot of solid work in the past, it was confirmed after many years of trial planting in many places.

Throughout the history of science, several leaps in human understanding of the world mainly lie in: the results predicted by the old theory are very different from the new measured results, or the old theory does not predict the new measured results, or the old theory can not reasonably explain the new measured results. Therefore, demonstration is the scientific method that should be emphasized most.

After long-term practice, it is generally recognized that science should have three characteristics: (1) objectivity: scientific research and discussion must comply with objective reality; (2) Verifiability: the conclusion of scientific research must be verifiable; (3) Systematicness: scientific research and scientific theory must be systematic and complete. This is why people call modern science empirical science.

Dialectical materialism holds that practice is the only criterion for testing truth, which is determined by the nature of truth and the characteristics of practice. Truth is a subjective and objective understanding; It is necessary to make subjective and objective judgment on whether it is in line with the objective. In other words, as the standard of truth, it must have the characteristics of connecting subjective and objective, which only depends on practice. Well, scientific theories that have been recognized and accepted in practice in the history of human science, such as Newtonian mechanics and Einstein's theory of relativity, all have such characteristics. Therefore, some people just want to overthrow it by relying on their own perfect logic, which is no different from the moon in the water and the flower in the mirror.

Compared with science, pseudoscience also pays attention to logic, and even quantification - listing a bunch of equations that are not sharp, but they can not pass the strict empirical test because they violate the recognized scientific theory. Therefore, the answer to how to distinguish science from pseudoscience is clear.

In a word, researchers pay attention to reliable logical reasoning, which can reduce the chance of making mistakes, but they may not get a correct understanding; To confirm the correctness of cognition, we should only prove the ear, and there is nothing else. In view of this, in order to achieve twice the result with half the effort on the journey of scientific exploration, researchers must understand this truth.