“一”散见于《庄子》内外杂篇中，且与文本中其他重要概念密切相关，是贯穿于《庄子》中的重要线索。通过对其文本中的“一”进行全面考察，本文认为，“道通为一”精当地概括出了《庄子》中围绕“一”建立的思想系统的核心。具体而言，这一系统由形上学视域、政治哲学视域与境界-工夫论视域三个层面建构而成。
形上学视域下的“一”集中体现为作为本原的道和作为基质的气，“道”体现了“一”的本原义及其所具有的整全义与无差别义，由此也引出了“道”无差别地辅育万物，即其作为普遍原则而作用于事物的功能性；“气”则集中体现了“一”的贯通不滞，与其相关的“游”“化”“阴阳”等概念也蕴含着流通与变化的特性。作为万物生发变化之根据的“道”落实于价值层面的规范和引导中：高妙的道体作为群体统御的形上根据，其虚静不滞、凝一不二的特性是至人或圣王需要具备的品质，在治国与安民的实践中具体表现为无为无心的统治举措和对百姓自然真性的顺应，最终指向一种人心淳一、无知无欲的“至德之世”。政治哲学视域下的“一”既表现为理想统治下每一个体及整个群体所表现出的淳朴自足、冥然淡漠，也表现为统治者“无心之治”的具体举措；由此，可以将“一”的原则视为对统治者与民众共同提出的要求与希冀。在境界-工夫论视域中，天道之“一”下落到个体身上，就直接显现为境界之“一”，达到至高境界的圣人即是“一”特质的集中体现。圣人能够会通万物之存在，不因境遇的分别而产生好恶分别及较大的情感波动，其内心是虚静而与化俱往的。圣人的人格经由与道体的感通与合一而得以完善。至于如何以工夫成就境界，如何达道，则首先涉及到对道体的直觉体认，即遣除杂念、专一心神，然后“听之以气”；进而以技艺的操练与熟稔作为体道的中介，达到与物合一、通而不滞的境界；这也涉及到身心性命的存养之术，即通过守一、抱一使身心恒处于和乐的状态。
合而言之，《庄子》的“一”之特质集中反映在“一”“多”关系的张力中，具体包括“多摄于一”与“一融于多”两方面，“一”与“多”在相互嵌套中相互成就。同其他先秦思想家相比，《庄子》中的“一”思想所具备的整体性思维、超越性思维、方法论思维可谓别具一格、颇有洞见，在当时及后世都产生了深远的影响。

"One" is scattered throughout Zhuangzi and is closely related to other important concepts, and it is an important thread that runs through Zhuangzi's philosophy. Through a comprehensive examination of the "one" in Zhuangzi's text, this paper argues that " All things by means of the Dao are united as one " precisely summarizes the core of the ideological system built around "one" in Zhuangzi. Specifically, this system is constructed at three levels: the metaphysical, political, and realm perspectives.
The "one" in the context of metaphysics is centrally embodied in the Dao as the origin and the Qi as the foundation, with the Dao embodying the original meaning of the "one" and its holistic and undifferentiated meaning. This also leads to the function of "Dao" as a universal principle to nurture all things without distinction; "Qi" is the embodiment of the unbroken and released "One", and its related concepts of "you," "transformation," and "yin and yang" also imply the characteristics of circulation and change. The Dao, which is the basis for the growth and change of all things, is implemented in the norms and guidance at the value level: the noble Dao body, as the metaphysical basis for the rule of the group, its characteristics of being empty and quiet, undetermined and concentrated are qualities that the supreme person or the holy king needs to possess, which is embodied in the practice of governing the country and the people as a measure of rule without doing anything and conforming to the true nature of the people, and ultimately points to a kind of "world of supreme virtue" in which people's hearts are pure and ignorant and desireless. The "one" under the political horizon is manifested not only in the simple self-sufficiency and indifference of each individual and the whole group under the ideal rule, but also in the specific measures of the ruler's "unintentional ruling"; thus, the principle of "one" can be regarded as a demand and hope for the ruler and the people. In the in the vision of the realm, when the "one" of the Dao falls on the individual, it directly appears as the "one" of the realm, and the saint who reaches the supreme realm is the concentrated embodiment of the "one" trait. The saint is able to understand the existence of all things, does not have a distinction between likes and dislikes and greater emotional fluctuations due to the distinction of circumstances, and his heart is quiet and harmonious. The personality of the saint is perfected by the sense of unity with the Dao. As for how to achieve the realm with work, how to attain the Dao, it first involves the intuitive realization of the Dao, that is, to get rid of distracting thoughts, concentrate on the mind, and then "listen to it with the Qi"; and then use the practice and mastery of the technique as the intermediary of experience of the Dao, to achieve the realm of unity with the things and the communication without stagnation; this also involves the art of the preservation of physical and mental life, that is, to keep the body and mind in a state of harmony and happiness through keeping and holding the oneness.
In sum, it can be said that the quality of "one" in Zhuangzi is reflected in the tension between "one" and "many", which includes "many in one" and "one in many", and the mutual achievement of "one" and "many" in the interweaving of both sides. Compared with other contemporaneous thinkers, the idea of "one" in Zhuangzi is unique and insightful in its holistic thinking, transcendental thinking, and methodological thinking, and it has had a profound impact on both the present and future generations.