The evocation of an emotion beyond expression--of "thoughts that do often lie too deep for tears"--is the special Zen aesthetic realm of _yugen_. The quality, heightened to almost unendurable levels by poetry, is that of a Zen landscape: sparse, monochromatic, suggestive. Universal human emotions are cloaked in obscurity rather than set forth explicitly. The passion is open-ended, a foreboding sonnet with the last line left for the listener to complete. Zeami and other No poets believed that the deepest sentiments cannot be conveyed by language; the poetry merely sets the stage and then sends the listener's imagination spinning into the realm of pure emotion, there to discover an understanding too profound for speech. In Western terms, if King Lear were a _shite_, he would speak in understated terms of the darkness of the heath rather than chronicle his own anguish. The concept of _yugen_, the incompleteness that triggers, poetic emotions in the listener's mind is, as has been previously noted, an extension of the Heian concept of _aware_. Like _yugen_, _aware _describes not only the properties of some external phenomenon but also the internal response to that phenomenon. _Aware _originally meant the emotional lift and sense of poignancy experienced in contemplating a thing of beauty and reflecting on its transience. Yugen extends this into the realm of eternal verities; not only beauty but all life fades, happiness always dissolves, the soul passes alone and desolate. In an art form that transmits _yugen_, none of this is stated; one is forced to feel these truths through suggestion, the degree of feeling depending, of course, upon the sensitivity of the individual. One can find excellent examples of _yugen _in almost any No drama of the fifteenth century, like the following from "The Banana Tree" (Basho), by Komparu-Zenchiku: _Already the evening sun is setting in the west, Shadows deepen in the valleys, The cries of homing birds grow faint.3 _ Here the sense of universal loneliness at nightfall, the emptiness one feels in a desolate locale, the Gothic coldness that penetrates from the physical senses into one's interior emotions, are all much more fully realized through the simple evocation of the scene than would be possible by detailing them explicitly. The mournful call of evening birds in the bleak, empty, windswept fields cuts, like the No flute, to the very core of one's feelings.