Medicine is a metaphor. The important task of saving the country, in Lu Xun's view, is by no means up to the revolution launched by the petty bourgeoisie. Because of their inherent defect of being divorced from workers and peasants, they are always in a weak position in the comparison of state power. Those who are sincere and enthusiastic about saving the country at the cost of their lives will not get the understanding of ordinary people, let alone the support of most people, and eventually die for their country and be beheaded, but their blood is taken as superstitious drugs for treating tuberculosis by unconscious people.

The bright line of medicine is to describe the ignorance of the public; Its hidden line praised the revolutionary's dedication. Using human blood steamed bread to connect the two clues of light and darkness highlights the ignorance of the masses, but also makes the dedicated revolutionaries feel an unbearable sadness and loneliness. What the author reveals is not Yu Xia's mistakes and shortcomings, but the weakness of the masses. Moreover, this weakness is not generally exposed, but is more deeply exposed in connection with revolution and revolutionaries. It is true that Yu Xia is lonely and sad, but the author does not analyze the subjective reasons for his loneliness and sadness, such as "being divorced from the masses", but focuses on revealing the objective reasons for this sadness and loneliness. When analyzing the objective reasons, the author does not focus on revealing the cruelty and cunning of the reactionary rulers, but on depicting the numbness and ignorance of the masses. In other words, revolutionaries are sad and lonely because they have deeply tasted the ignorance and numbness of the masses. Lu Xun once talked about this work with his friends. He said: "medicine describes the ignorance of the masses and the sorrow of revolutionaries;" Or the sorrow of revolutionaries because of the ignorance of the masses; To put it more bluntly, revolutionaries sacrificed their lives for the ignorant masses. The masses don't know who this sacrifice is for, but because of their own ignorance, they think that this sacrifice can be enjoyed ... "6. We think that this passage of Lu Xun has clearly explained what his central idea is. If it is necessary to make a summary, the theme of Medicine is: the masses are still ignorant, they urgently need revolution, but they are not conscious and even hostile to revolution. To make a revolution, we must use scientific and democratic ideas to liberate them from the long-term rule of Confucius and Mencius and feudal superstitions. Otherwise, the revolution has no hope of success.