Many methods of psychological deception in a Zen garden exploit instinctive visual assumptions in much the same way that a judo expert uses his victim's body for its own undoing. A common trick is to have a pathway or stream disappear around a growth of trees at the rear of a garden in such a way that the terminus is hidden, leading the viewer to assume it actually continues on into unseen recesses of the landscape. Another such device is the placement of intermittent obstructive foliage near the viewer, causing the diminution in perception that the mind associates with distance. Japanese gardeners further enhance the sense of size and depth in a garden plot by leaving large vacant areas, whose lack of clutter seems to expand the vista. Dwarfing of trees is also a common practice, since this promotes the illusion of greater distance. And finally, flowers are rigidly excluded, since their appearance would totally destroy all the subtle tricks of perspective. Zen garden masters prefer to display their flowers in special vase arrangements, an art known as Ikebana. The manipulation of perspective and the psychological deception of the Zen garden are always carefully disguised by giving the garden an appearance of naturalness and age. Garden rocks are buried in such a manner that they seem to be granite icebergs, extruding a mere tip from their ancient depths, while the edges of garden stones are nestled in beds of grass or obscured by applications of moss, adding to the sense of artless placement. Everything in the garden--trees, stones, gravel, grass--is arranged with a careful blending of areas into a seemingly natural relationship and allowed to develop a slightly unkempt, shaggy appearance, which the viewer instinctively associates with an undisturbed natural scene. It all seems as uncontrived as a virgin forest, causing the rational mind to lower its guard and allowing the garden to delude the viewer with its artificial depth, its psychological sense of the infinite. The transformation in garden art the Zen artists wrought can perhaps best be emphasized by comparing the traditional Chinese garden with the abstract landscape created by Japanese artists of the Ashikaga and later eras. 'The Japanese regarded the garden as an extension of man's dwelling (it might be more accurate to say that they saw the dwelling as an extension of the garden), while the Chinese considered the garden a counterpoise for the formality of indoor life, a place to disown the obligations and conventions of society. It has been suggested that the average Chinese was culturally schizophrenic; indoors he was a sober Confucian, obedient to centuries-old dictates of behavior, but in his garden he returned to Taoism, the joy of splendor in the grass, of glory in the flower.