Taoism emerged around 500 BCE during the Zhou Dynasty in China. Rather than concerning with state duties and administrations as a great number of ancient Chinese thinkers did, Taoism encourages anchoritism - a sense of withdrawal from public affairs to allow for the search for a vision of the transcendental world of the spirit. Tao Te Ching, the most venerated text in Taoism, was written by Lao Tzu during his departure from Zhou Kingdom of China. In the same century as the founding of Taoism, Greek philosopher Heraclitus attempted to diverge from previous thoughts from Milesians and proposed the doctrine of fluxism, which views things as being in a perpetual flux; and unity of opposites, which states that there is a universal co-instantiation of contrary qualities. Despite the distinct cultural backgrounds in which both doctrines were composed, Tao Te Ching and Heraclitan philosophy bear close resemblance to each other in their notion of the unity of the opposites.
Both Tao (sometimes translated as the Way) and the Heraclitan Logos are illustrated as an underlying and omnipresent law which governs the flow of nature. Heraclitus proposed the concept of Logos, which acts as an eternal and unchanging principle transcending from the time of creation, and available for individuals to seek through contemplation. Heraclitan Logos, as the foundation in which his metaphysics was built upon, is grounded in the dialectical opposition of being and non-being, and is revealed through a series of oxymoronic expressions which create a dynamic unity of reality by integrating contrasting states as one. An example is his fragment 50 “listen not to be but to the logos, it is wise to agree all things are one”, which explicates his belief of an underlying order, namely the Logos, to the multiplicity in the world.
On the other hand, Tao is referred to by the line “Tao (models itself) on that which is naturally so” from poem 25 in Tao Te Ching as a natural law, which encompasses the fundamental properties of every aspect of the cosmos. Moreover, poem 4 describes Tao as “An abyss, like an ancestor, from which all things come”, yet unlike a creator, the opening line of the poem states directly that “Tao itself is a void”, and lacks sensible qualities. This union of emptiness and infinity draws a parallel to Chuang Tze’s lines describing Tao: “Pour into Tao: it will not be filled. Pour out of it: you can never exhaust it.”. Through which, Lao Tze and Chuang Tze demonstrated that Tao itself, along with other entities of the cosmos, exist as a unity of contrary qualities that instead of producing a clash, complement each other to coordinate different aspects of the nature. This idea is further illustrated through Taijitu, the visual symbol of Taoism. Taijitu is composed of a circle divided into two swirling section, in which black and white flow into one another, presenting the idea of “Yin-Yang” - two opposite forces that constitute all phenomena, developed by a group of ancient Chinese scholars as a dualist purview of nature. While Yin symbolizes for the dark, negative, and feminine, Yang represents the bright, positive and masculine. Apart from the Taijitu symbol, the idea of dichotomy between Yin and Yang, along with the distinction between opposites, is further rejected by the representation of a balance and interdependence of Yin and Yang through a number of poems. For instance, it was written in poem 2 that “Is and Is not produce each other. Hard depends on easy, Long is tested by short, High is determined by low, Sound is harmonized by voice, After is followed by before.”, which conveys the notion of antithetical qualities existing in complementary pairs, and arising from human feelings.
According to Heraclitus, the fundamental functioning of human soul is reflected upon the principles governing the world, as he claimed that the substance in which the soul is composed of is identical to the substance of nature, that is, pure becoming. Thus, Heraclitan Logos can be separated into two principal senses: anthropological and cosmological, while the former acts as the force regulating the mankind, regarding each human action in frame of reference to infinity, as indicated in fragment 71: "A man hears himself called silly by a divinity as a child does by a man.", the latter is presented as a universal law embodying all qualities and beings into a unified oneness. Through which, Heraclitus introduced the idea of a parallel between one’s inner self and the macroscopic world. Yet in order to grasp a comprehensive view of the latter, one must break free from the infringement of oneself and thus to apprehend the ultimate truth of the reality, the Logos. This parallel of the inner structure of the soul and the order existing on a greater scale, the cosmos, can also be found throughout Tao Te Ching, but rather in a sense that encourages one to depart from the sensible surroundings, as indicated in poem 47: “Tao may be seen apart from the windows, the further you go, the less you will know”. Similarly, according to the lines from poem 25 “Man models himself on earth, Earth on heaven, Heaven on Tao, And the way on that which is naturally so”, there is an inherent connection between mankind and Tao, to understand which the former is ought to take the latter as the fundamental principle guiding their daily behaviors, through observation and contemplation of the natural world.
In a notably similar manner, both Heraclitus and Lao Tzu placed an emphasis on the “unapparent” and “unnamed” aspect of Logos and Tao, respectively. The idea of Harmonia, which lies underneath the empirical reality, is introduced in Heraclitan fragment 54, which states that “The unapparent connection is more powerful than the apparent one.”. Through comparing the sensible phenomena of the cosmos and the Logos unifying the multiplicity of the world, Heraclitus suggested that the former outweighs the latter. Likewise, the opening lines of the Tao Te Ching “The Tao that can be told is not the eternal Tao” presents an objection to worldly affairs and a value of intellectuality, which indicates the comparatively greater significance of one’s ability to deduce a natural law through constant meditations and contemplations over believing the empirically observable. Through which, both Heraclitus and Lao Tzu showed an optimistic view that the world is inherently understandable. Nevertheless, while the former’s attempt to establish an order among the chaos and multiplicity of the world may have been influenced by his Milesian predecessors, who sought to understand the causes and constituents of natural phenomena, that of the latter was likely to be a direct result of the political corruption, which provoked Lao Tzu’s shift of focus from the incessant social strife to an overall sense of harmony.
Despite the prominence of the central notion of harmony in the doctrines of both, it is believed that Heraclitus and Lao Tzu held contrasting views on the role of union and harmony in society. Heraclitus extended his Logos from a natural law to a moral principle for all human beings by promoting oppositional processes, as referred to by him as “stifle”, among men themselves. Stemming from his contempt for mankind, Heraclitus showed a notable praise of wars and conflicts, as indicated in fragment 80: “We must know that war is common to all and strife is justice, and that all things come into being through strife necessarily.”. On the contrary, Lao Tzu showed an aspiration for a harmony within the mankind throughout Tao Te Ching, which can be attributed to the political situation in the Zhou Dynasty, that the corruption and conflicts within the governing body caused widespread misery and pain among Chinese civilians. Furthermore, the idea of "unity of men and nature" in Taoism does not only reflect the reverence for heaven and earth, but also affirms the intrinsic value of human beings, which vary significantly from Heraclitus’s view of mankind.
In conclusion, the unity of opposites, proposed by Heraclitus and Lao Tzu from distinct cultural and political backgrounds, display a number of similarities, predominantly their belief that reality is constituted from co-existing and complementary sets of dynamic oppositions. While bifurcation and differentiation separate opposites from a rather logical and empirical approach, a union of opposites, synergetic though antagonistic, as Heraclitus and Lao Tzu believed, produce novelty and complexity that dialectically make up the oneness of the cosmos. Nevertheless, one may argue that the Heraclitan Logos is pure logical law of the identity in process of being and non-being, and thus shall be taken merely as an ontological doctrine. Taoism, to a greater extent, focused on one’s inner peace and harmony, and attempted to promote tolerance. Therefore, different from the Heraclitan Logos, Tao also represents a route of life, a mode of behavior in addition to its ontological implications.