The original text of the motto of the cross comes from the Confucian classic The Doctrine of the Mean. Chapter 20 of The Doctrine of the Mean says: "erudition, interrogation, deliberation, discernment and faithfulness." According to the original meaning of the golden mean, people have the nature of "sincerity". As long as you practice according to the nature of "sincerity", you can cultivate yourself into a "gentleman" through five links: learning, asking, thinking, distinguishing and doing.
In fact, the doctrine of the mean is to be impartial and not to go to extremes as the guiding principle, so that the literati in the feudal era will not violate the feudal purpose and become the successors of feudalism.
At the end of Ming Dynasty and the beginning of Qing Dynasty, with the changes of society, the famous thinker Gu developed the traditional doctrine of the mean, emphasizing "erudite and determined, asking questions and thinking close", and combining learning with determination, so he made a new interpretation of "erudition": "erudition is in writing, and being ashamed of oneself". The "writing" Gu refers to is no longer a pure ancient prose, but includes all state affairs in the world. The "shame" he refers to refers not to the honor and disgrace of individuals, but to the honor and disgrace of all people.
The guiding ideology of erudition has expanded from personal self-cultivation to an urgent social event, so he unified learning, questioning, thinking and determination. Gu is a patriot seeking truth from facts. He can make a new interpretation of traditional education according to the needs of the new situation.
Sun Yat-sen was in the era of the Great Democratic Revolution. For the needs of the revolution, he attached great importance to education and trained a generation of talents to revitalize China and rebuild civilization.
From 1923 to 1924, he proposed to establish two schools in Guangdong, Huangpu Military Academy and Guangdong University, in order to cultivate talents who serve the country, the people, the society and the world. Cross school motto is a revolutionary new educational policy and content that he inherited from the traditional educational form. It can be said to be a milestone in the innovation of modern thought.