The benefit of Materialism lies in the fact that if people believe that the world exists objectively then they can explain the source of the alienation of experience (why experience is not what we want), and they will adopt a rigorous attitude, actively explore, and seek greater benefits for mankind. Therefore, the belief in materialism comes from human interests. Without human interests, materialism has no meaning. If another belief can produce the same benefits, then materialism has no advantage. The ideological experiment of the brain in the cylinder seems to be a devastating criticism of science. In fact, it just  once again validate the subjective idealism theory of Descartes and Hume from a special perspective. And this is truly devastating of materialism by subjective idealism. Starting from materialism, it inevitably infers the conclusion of subjective idealism.

On the other hand, starting from subjective idealism, we will infer the conclusion of materialism. Subjective idealism does not recognize the existence of the objective world as transcendental and believes that it must proceed from consciousness. However, from the perspective of consciousness it is also possible to confirm the objecti- vity of feelings. Objectivity comes from the need for logical unity between consciousness. When you hit the wall, if you do not admit the feeling and say,“I just did not hit the wall”, then you continue to move forward and you will get the feeling of hitting the wall again. Concepts and emotions can be changed at will, but experience cannot be changed at will because it has a specific relationship with people's interests.

The cylinder brain receives the computer-simulated life experience, which may be considered as real life experience by the brain within a short time, but it will inevitably be doubted after a long time on many reasons. First of all, there is no technology that can completely imitate the real environment. Three-dimensional maps or game animations are clearly different from the facts. Second, even if the simulation of the environment is very realistic, the simulation of human responses cannot be realistic. People have a wealth of ideas. Each person has a different personality. Computers cannot realistically imitate the language and behavior of different people. Third, the real brain can dominate the limbs, move around, write and draw, and produce a variety of products that can change the world. Computers can imitate some behaviors, but they cannot imitate the detailed feelings and results of behavior. The brain in a cylinder feels itself like a disabled person. Fourth, there are always illogical contents of simulation. Virtual scenes can be replaced instantly. They can move from China to the USA, from earth to Mars, or suddenly disappear. This is impossible for real scenes. The real objective world has specific laws that are not based on human will. It is an alienation. Subjective idealism can never erase this objective alienation.

Since both