Yūgen pervades all Japanese arts including the budo of the martial arts. A word to signify “a profound, mysterious sense of the beauty of the universe… and the sad beauty of human suffering.”(Ortolani, 325). Ortolani, Benito. The Japanese Theatre. Princeton University Press: Princeton, 1995).
Daisetsu Teitaro Suzuki, in Zen and Japanese Culture (New York)
Yugen is a compound word, each part, yu and gen, meaning “cloudy impenetrability,” and the combination meaning “obscurity,” “unknowability,” “mystery,” “beyond intellectual calculability,” but not “utter darkness.” An object so designated is not subject to dialectical analysis or to a clear-cut definition. It is not at all presentable to our sense-intellect as this or that, but this does not mean that the object is altogether beyond the reach of human experience. In fact, it is experienced by us, and yet we cannot take it out into the broad daylight of objective publicity. It is something we feel within ourselves, and yet it is an object about which we can talk, it is an object of mutual communication only among those who have the feeling of it. It is hidden behind the clouds, but not entirely out of sight, for we feel its presence, its secret message being transmitted through the darkness however impenetrable to the intellect. The feeling is all in all. Cloudiness or obscurity or indefinability is indeed characteristic of the feeling. But it would be a great mistake if we took this cloudiness for something experientially valueless or devoid of significance to our daily life. We must remember that Reality or the source of all things is to the human understanding an unknown quantity, but that we can feel it in a most concrete way.
As with Zeami’s yūgen, there is Rikyuu’s wabi (a sense of tranquil solitude), and Basho’s sabi. A world of aesthetics where all the forms evolved in the Muromachi period or descended directed from it.
Yūgen is exceeding hard to convey—it eschews the linear thought processes, and cannot be grasped, however much the logical capacity of our minds; but it does manifest upon encountering creativity, within ourselves, others, as also in insentient objects. And of course, creativity too is a source hard to fathom. Yūgen in that sense is the becalmed self free of anxiety, strategy, machinations, doubt—a self that expresses a form, a shape, a space, a movement, discovers a formula—which truly appears to evoke wonder in the one who experiences. An idea of mystery pervades the comprehension and feeling of seeing into something of the unknown that remains unknowable.