自古以來，中國人所持有的「天下」觀念，實乃一種宏觀的地理與文化認知，其形成可追溯至上古時期。在中國神話中，「昆侖山」被賦予了作為「天下」中心的崇高地位，可能位於現今裡海與黑海之間的高加索山脈一帶。這一推論不僅揭示了中國古代對於「天下」的廣闊認知，同時也暗示各大文明之間可能存在的深遠聯繫。本研究以人類命運共同體理念為理論視角，深入探討全球人類在面對大洪水這一共同災難記憶時，如何從同一源頭分化出多姿多彩的世界文明。通過分析神話中的合成生物、太陽神形象以及大洪水敘述，本研究揭示不同文明之間在深層次上的共通性和相互聯繫。在此基礎上，本研究提出一種超文化主義層面的人類學共同認知哲學，認為世界各地的文明在本質上都是人類共同智慧的結晶。此研究不僅有助於深化對中國古代「天下」觀念的理解，更可促進全球文明之間的交流與融合，喚起人類對共同家園的情懷及認同話語。在全球化日益深入的今天，此研究為人類面對共同挑戰提供瞭重要思考方向，引領我們走向一個更加和諧、包容和繁榮的未來。

The ancient Chinese notion of "Tianxia" (worldview; all under heaven) symbolizes a comprehensive understanding of geography and culture, with its origins in antiquity. Central to this concept is Mount Kunlun, regarded in mythology as the pivotal point of "Tianxia," possibly situated in the Caucasus region between the Caspian and Black Seas. This suggests not only the broad scope of ancient Chinese worldview but also hints at potential deep ties between different civilizations. The research adopts the idea of a shared human community to explore how global cultures, united by the collective memory of a cataclysmic flood, diverged to form distinct civilizations. Through examining mythological creatures, sun god representations, and flood stories, the study identifies fundamental similarities and connections across cultures. It proposes a cross-cultural anthropological theory that posits global civilizations as manifestations of collective human intellect. This work not only enriches our comprehension of "Tianxia" but also fosters cross-cultural interactions, reinforcing a global sense of belonging and identity. In an era of growing globalization, this research offers vital insights for addressing universal challenges, guiding us towards a more united, inclusive, and flourishing future.