In the context of art it is remarkable how the Japanese garden deals with materia or substance. In the following four characteristics. The borderline between art and nature is astonishingly vague. There is a very strange familiarity between very different things. Gravel can stand for water.
Monks have to move it frequently, thus introducing the category of movement.
In other words, there is a strange ambivalence, a strange absence of clear definition which eases the metaphorical. They are not just part of a natural environment, they are the main theme of this art. It does not present itself on a canvas or screen, but in the vital landscape of man. Of course, this corresponds basically to the domain of the architect. In short, there is something very puzzling in all this.