In dark, saturated ink, the Zen monk Nishigaki Sōkō wrote an impressive, solitary character with a bold and a vigorous brush stroke on the paper. The strong contrast between ink and paper as well as the massive character that was set without any trace of pause give a clue of its importance. Though the calligraphy was written in jet black ink, some parts within the brush strokes give the look free on the paper. The so called “flying white” speaks of the moment when the brush’s hair is not touching the paper as if flying over the ground. The ink captures a dynamic process and irretrievable writing gesture in time. Its vibrant impression invites the viewer to follow the movement of the brush and its “ink trace” (bokuseki 墨跡) – as calligraphies of eminent Zen monks were called since 13th century. Nishigaki Sōkō started with a thin horizontal line that is then crossed from the left to the right with three vertical, bold brush strokes. The last one is a bit longer and continuous in a loop followed by a narrow, downward zigzag that keenly abbreviates the four tiny dots of the normed character “wu” 無. The single Chinese word – that is spelled “mu” in Japanese – means “no” or “nothing” and hints as an abbreviated quotation to several stories of the Zen Buddhist canon.
In his famous poem for succeeding the dharma transmission, the sixth patriarch Huineng (638–713) is said to use the word in the quintessential line: “Originally, [there is] not a single thing” (本来無一物, J.: honrai muichi butsu). The single poem line grasps the very essence of the Zen Buddhist teaching in five Chinese characters. It states that basically there do not exist any concepts of the world or of our self by nature. They are a construction of our own mind. According to the Buddhist conviction of emptiness (Skr. śunyatā, Jap. kū 空) the world does not consist of permanent, unalterable things or substances. The world is rather an everlasting becoming that cannot be expressed in its wholeness by discriminating and thus limiting words or concepts.
The same idea is expressed in a more humorous way a bit later in form of an kōan that was published 1229 in the Wumen guan 無門關 (Jap. Mumonkan, “Gateless Checkpoint”). According to that case, a monk came to master Zhaozhou Congshen 趙州從諗 (778–897, Jap. Jōshū Jūshin) and asked him: “Does a dog has the Buddha nature?” Zhaozhou just replied, possibly in a barking like tone: “Wu!” (“No [such thing]!”). Here, Zhaozhou does not directly answers the question by just saying that a dog has no Buddha nature. Rather, he replies on the concept that underlies the question of the monk, which is a dualistic distinction between the enlightened and the unenlightened mind. What he says is: Stop speculative thinking! If one realizes that there is “no single thing” in the world we can stick on, one frees himself from suffering and abides in the peaceful serenity of nonassertion. That is what the calligraphy reminds of.