Predictability and stability all require time to verify. When the theory is presented, you need some alternative standards to verify immediately. The logically unified theory is the most stable and predictable, so the logically unified theory is the truth. Galileo's thought experiments show that Aristotle's theory is illogical. The only logically unified theory is that the rates of all free falls are the same. The logical thoroughness of philosophy is much better than that of general theories. The mission of philosophy is to realize the logical unification of all theories and to build the entire theoretical building into a completely self-contained system.

The fourth alternative standard of truth is the principle of simplicity, because simple theory is easy to guide practice. People's thinking ability is limited, and although people can use complex theory to get their goals, it is easy to make mistakes. Occam stated: “Every thing that can be achieved with less means does not require more means.” “If it is not necessary, it should not increase the number of real things.” This proposition is the famous Occam's razor. But it should be written in the scientific language: Simplicity is the standard of truth.

Occam's razor once judged religion to be unscientific. In some areas, religion is more successful than science, but religious interpretation depends on God's will,which is complex and changeable. Therefore, religious predictions often make mistakes. It cannot meet people's needs and it is not conducive to social progress. This is the real reason why Occam's razor shaves religion. The standard of simplicity is equal to the standard of practice.

The premise of the choice of simple theory is that both theories can explain and predict the same phenomenon. If the interpretation and prediction of the simple theory is inferior to complex theory, then the complex theory must be chosen.

Based on the previous discussion, we can get the final conclusion of the truth test method.

Trilogy Theorem of Truth Test: The subject for testing truth is each individual person. Practicality is the ultimate criterion for testing truth. The process of testing truth consists of three stages: 1. Verify the logical unity and simplicity of the hypothesis; 2. Verify the stability of the hypothesis; 3. Verify the predictability of the hypothesis.