Within the four seas, all are brothers; even at the ends of the earth, we are like neighbors.

This famous line comes from Wang Bo's "Farewell to Prefect Du on His Departure to Shuzhou," an eternal masterpiece among Tang dynasty farewell poems. At the time, Wang Bo was serving in Chang'an while his close friend Prefect Du was about to depart for Shuzhou (modern Chengdu, Sichuan) as prefect. The poet composed this farewell poem. "Within the four seas" refers to all within China's borders, "bosom friends" indicates those who understand each other profoundly, "heaven's edge" means the farthest reaches, and "neighbors" signifies close proximity. These lines express that true friendship transcends spatial distance - even separated by mountains and rivers, hearts remain closely connected. Wang Bo was barely in his twenties when composing this poem, yet displayed emotional maturity and lofty vision beyond his years. This work comforts not only the departing friend but all those experiencing separation, embodying Tang literati's broad-mindedness and profound understanding of friendship.

The profound insight lies in redefining the relationship between space and emotion. Traditional views consider distance as emotion's enemy - "distant relatives are not as good as close neighbors" - but Wang Bo reverses this, proposing that true friendship overcomes spatial barriers. The word "exist" is masterfully used, both indicating presence and implying preservation/treasure, suggesting bosom friendship forever remains in the heart. "Like" is not hypothetical but affirmative, emphasizing the reality of spiritual connection. Through contrast, the poet juxtaposes vast geographical space (within seas, heaven's edge) with intimate emotional distance (bosom friends, neighbors), creating artistic "spatial compression" and demonstrating Chinese classical poetry's mastery of "emotion governing scenery." This emotional philosophy applies not only to friendship but extends to family and romantic love, becoming important wisdom in Chinese culture for handling human relationships.

According to "Old Tang History: Literature Biography," during Wang Bo's service in Chang'an, he became very close with Prefect Du. Du's given name is unknown; "Prefect" was Tang dynasty's respectful title for county magistrates. Du was appointed prefect of Shuzhou (modern Chengdu, Sichuan), requiring months of treacherous travel via the Shu Road from Chang'an. Wang Bo held a farewell banquet at Baqiao Post Pavilion in Chang'an and composed this poem during the feast. Legend holds Wang Bo was only sixteen when writing this (some say around twenty), already displaying remarkable talent. "City towers assist the three Qin, wind and mist gaze toward five crossings" describes the farewell location and friend's journey, while "within the four seas there are friends, at heaven's edge we are like neighbors" offers deep comfort to the departing friend. Later Prefect Du achieved outstanding governance in Shuzhou, with frequent correspondence between them confirming their profound friendship. This poem was widely recited at the time, becoming representative of Tang farewell poetry, later included in "Complete Tang Poems," surviving to this day.

This line has profoundly influenced Chinese culture, becoming the classic expression of deep friendship. In literary creation, from Tang poetry and Song lyrics to Ming-Qing novels, countless writers quote or adapt this line - Li Shangyin's "When shall we together trim west window candles, while speaking of Ba Mountain night rain" continues this emotional expression transcending space. In international cultural exchange, this line is widely translated, becoming an important window for foreigners to understand Chinese friendship concepts. Modern diplomatic occasions frequently quote this line to express international friendship, such as Premier Zhou Enlai using it to describe Sino-African friendship. In popular culture, "within the four seas there are friends, at heaven's edge we are like neighbors" is used as letter closings, gift inscriptions, and even internet age blessings. This line also influenced East Asian cultural sphere, with similar expressions in Japanese and Korean literature. In modern education, this line appears in primary and secondary school Chinese textbooks as required memorization, its emotional wisdom continuing to nourish generations of Chinese hearts.

To apply this line's emotional wisdom to modern life, consider these approaches: First, establish "digital soulmate" networks using social media and video calls wisely to maintain regular deep communication with distant friends, making technology serve rather than replace emotion. Second, cultivate "spiritual neighbor" communication habits - even separated by vast distances, share life details and emotional experiences to maintain synchronized spiritual worlds. Third, create "global friendship circles" - international friendships formed through study, work, or travel, maintained through cross-cultural understanding and respect. Fourth, transmit this friendship concept within families, educating children about sincere friendship's value and learning to establish profound connections with diverse backgrounds. Fifth, apply this concept to workplace relationships, building team culture based on shared values in remote work and international cooperation. Sixth, participate in international volunteer or cultural exchange programs, practicing the "within the four seas there are friends" concept, making global friends while helping others, allowing this ancient line to gain new vitality in contemporary society.