Xu Kaiwen, deputy director of Peking University Mental Health Education and Counseling Center, gave a speech entitled "The Economics of Time Hollow Disease and Anxiety". Through investigation, he found that nearly 40% freshmen in Peking University felt "agitated and disgusted" with their study and life, and "didn't know why they were alive, and what was the value and significance of living". This phenomenon is called "hollow disease".

Logical thinking refers to the way or form of connecting and organizing the content of thinking. Thinking takes concepts and categories as tools to reflect cognitive objects. These concepts and categories exist in the human brain in a certain frame form, that is, thinking structure. These frameworks can organize different categories and concepts together, thus forming a relatively complete train of thought, which can be understood and mastered to achieve the purpose of understanding. Therefore, thinking structure is not only a cognitive structure of human beings, but also a structure of human ability to grasp objects by using categories and concepts.

The main contents of logical thinking include: subject, definition, classification, relationship and order. The subject defines who is the main and who is the auxiliary; Clearly define what is the theme; Classification defines categories divided according to different classification rules; The relationship between subject and object, and the relationship between different types of subjects, including relevance, inclusion, genus, attribution, etc. Order defines the order of each process.