There would have been no music were just one sound heard in this world. Common knowledge also goes that  delicious food can’t be prepared by using just one ingredient. Harmony is based on differences - this is an important philosophical rationale found in traditional Chinese culture. This rationale, summarized as “harmony with differences reserved” (和而不同，pronounced as he er bu tong), is the best way to handle relationships between countries, between nations and between individuals.
    Here is a story told in the Discourse of the State by Zuo Qiuming, a philosopher of China’s Spring-Autumn period some 2,500 years ago:
    When Prince Huan of the Zheng State was working as a court official, the Zhou Dynasty was facing a host of difficulties. So he asked Shi Bo, the royal historian, whether or not the dynasty would eventually collapse. “Sure,” Shi Bo replied. “This is because the supreme ruler of Zhou has got rid of those who are wise and honest, while staying close to those who are vicious and fatuous. He has abandoned the principle of 和(pronounced as he, meaning “harmony”), and instead, he has been pursuing the policy of 同(pronounced as tong, meaning “sameness”, denticalness).”
    Then Shi Bo explained what he meant. According to him, everything on earth will thrive when harmony, or 和, is achieved. But nothing can grow when the world is in a state of sameness or identicalness, or in a state of同. Harmony means simultaneous existence of things different in nature, which complement and enrich one another for the common good. When things of the same or identical nature are grouped to form an entity, that entity will eventually come to extinction. Based on this understanding, Shi Bo continued, ancient sovereigns always chose their queens from among women of alien countries or clans, and their ministers had always selected from among those who dared to air opinions different from theirs. The principle of harmony or和 calls for painstaking analysis and comparison of things different in nature. There would have been no music if just one sound were heard in the world. The world wouldn’t have become so kaleidoscopic if it allowed just one thing to exist. Likewise, there wouldn’t have been fruit of so many varieties if everything had the same taste. No comparison could have been made if the world had just one thing. The sovereign of Zhou had had his ability and wisdom deprived of by Heaven because he had abandoned the correct principle of harmony and was following the wrong policy of sameness. How could he prevent his powers from collapsing?
    In traditional Chinese culture,和(harmony) and 同 (sameness or identicalness) are important concepts. Harmony refers to an organic integration of things different in nature to attain a state of perfection, a state full of vitality in which things complement one another to the benefit of all. In situations of sameness or identicalness, however, things of the same nature are grouped in such a way as to be devoid of vitality. Traditional Chinese philosophy stands for attainment of harmony with differences reserved, regarding this as the best way to handle relationships between countries,  nations and  individuals.
    A similar story is told in another classic Chinese text, Spring and Autumn with Commentary by Master Zuo. The Duke of Qi, so goes the story, once visited a place named Zitian, where he was received by Yan Zi, a man of letters. Duke of Qi had the following to tell his host: “Among those court officials, only Ju is in harmony with me.” “Well,” said Yan Zi, “Ju is simply enjoying a sameness with you, and ‘harmony’ is not the proper word for your relationship with Ju.” “What is the difference between harmony and sameness?” Duke of Qi asked. “There is a vast difference between harmony and sameness,” Yan Zi said. “In preparing a soup, you boil fish and meat in water in a cauldron, and you use different ingredients to make the soup delicious. The soup will be tasteless if no ingredients are used. Ju is no politician because he is a yes man. If the sovereign says yes, he will say yes and if the sovereign says no, he will say no, just like preparing a soup with nothing but water.”
    Confucius, founder of Confucianism, summarized the harmony-sameness rationale in the following saying: “The gentleman stands for harmony while allowing reservation of differences; the small man stands for sameness while rejecting harmony.” The “gentleman” is a collective reference to people who are principled in their pursuit of what they think is ideal, and the “small man,” to those who are easily lured away from a principled stand or give it up under pressure. The Analects of Confucius, a collection of quotations from the Chinese sage, also has the following statement: “Harmony is of utmost importance to the rites that regulate human relations, but loss of principle is unwise for the sheer purpose of achieving harmony.”
    Here is how Lao Zi, another greater Chinese thinker, saw the principle of harmony: “Everything has two sides, yin and yang, the interaction of which results in harmony.” Yin陰and yang 陽 are among the most important philosophical concepts of traditional Chinese culture, denoting the feminine-masculine or negative-positive principle in nature.
    On October 24, 2002, Jiang Zeming, former Chinese president, spoke on the Confucius harmony-sameness rationale when visiting the State University of Huston, USA. “More than 2,000 years ago,” he said, “Confucius advanced the principle summarized as ‘the gentleman stands for harmony while allowing reservation of differences.’ That principle calls for harmony with freedom from stereotypes and reservation of differences with freedom from conflicts. Harmony is meant to achieve common prosperity and differences promote mutual complementation. This is an important guiding principle for social development, and also for the handling of human relationships. It epitomizes the importance of achieving orderly and balanced development of the various cultures.”
    The Book of the Mean, another Chinese classic, studies the concept of harmony (和) in combination with the concept of the mean (中, pronounced as zhong). Happiness, anger, grief and joy, the gamut of human feelings, are in a state of the man before they are expressed, according to the harmony-mean rationale. These will be in a state of harmony provided their expression conforms to certain established rules. The mean is the prerequisite for the survival of everything, and harmony is the best way for the development of everything. A proper balance of the mean and harmony helps everything find a proper place for itself in the universe, thus able to enjoy full and natural growth.
    By striving to build what it chooses to call a “harmonious society,” China wants to ensure both international and domestic harmony and harmony between the state and the individual. The ancient Chinese philosophical rationales on harmony definitely contributes to the endeavor.