That all opposites—such as mass and energy, subject and object, life and death—are so much each other that they are perfectly inseparable, still strikes most of us as hard to believe. But this is only because we accept as real the boundary line between the opposites. It is, recall, the boundaries themselves which create the seeming existence of separate opposites. To put it plainly, to say that "ultimate reality is a unity of opposites" is actually to say that in ultimate reality there are no boundaries. Anywhere.
The fact is, we are so bewitched by boundaries, so under the spell of Adam's sin, that we have totally forgotten the actual nature of boundary lines themselves. For boundary lines, of any type, are never found in the real world itself, but only in the imagination of mapmakers. To be sure, there are many kinds of lines in the natural world, such as the shoreline situated between continents and the oceans surrounding them. There are, in fact, all sorts of lines and surfaces in nature—outlines of leaves and skins of organisms, skylines and tree lines and lake lines, surfaces of light and shade, and lines setting off all objects from their environment. Obviously those surfaces and lines are actually there, but those lines, such as the shoreline between land and water, don't merely represent a separation of land and water, as we generally suppose. As Alan Watts pointed out so often, those so-called "dividing lines" equally represent precisely those places where the land and water touch each other. That is, those lines join and unite just as much as they divide and distinguish. These lines, in other words, aren't boundaries! There is a vast difference between a line and a boundary, as we shall presently see.
