在明末清初特殊的时代背景下，顾炎武对历史传统与现实问题进行了深刻反思，进而提出了著名的“亡国”与“亡天下”之辨。顾炎武的“国家观”总结了“国”的历史共同性，认为“国”是宗庙、社稷和国土三种要素构成的政治实体。顾炎武的“天下观”以“天下”的历史文化和语言传统为基础，以“仁义”为“天下”的核心内涵，以建设“风俗人心”为“保天下”的实践要略，以民族利益和文明兴亡重于一切的“夷夏之防”作为最高原则。顾炎武确定了“天下”之于“国家”的先决重要性，明确了文明内的责任分属，确立起每个人对于文明兴衰和民族兴亡的“责任主体性”。顾炎武以变焦“历史”与“现实”的反思视野，完成了对“天下”的意义重思。其“天下观”构成了“天下”概念的历史性语义流变中的重要内容，在中国历史上发挥了巨大作用，成为了现代中国社会建设和思想发展的重要文化资源。

In the special era of the late Ming and early Qing dynasties, Gu Yanwu made a deep reflection on historical traditions and realistic issues, and put forward the famous distinction between "the state" and "the world".Gu Yanwu's "state view" summarized the historical commonality of "state" and believed that "state" is a political entity that integrates the three elements of the ancestral temple, community and territory. Gu Yanwu's "view of the world" is based on the history culture and language traditions of "the world"; "benevolence and righteousness" are the core connotations of "the world"; the construction of "customs and morals" is the practical strategy of "protecting the world"; "protecting civilization from barbarism" is the highest principle with national interests and civilized life as the top priority. Gu Yanwu determined the prerequisite importance of "the world" to "the state", clarified the division of responsibility within civilization, and established everyone's "subjectivity of responsibility" for the development of civilization and nation.Gu Yanwu completed the reconstruction of the meaning of "the world" through reflection on "history" and "reality". It constitutes an important content in the historical semantic change of the concept of "the world", and has played a huge role in Chinese history. It has also become an important cultural resource for the social construction and ideological development of modern China.