We experience the world in a relatively orderly way. Things are laid out in space in such a way that some are to my right, some are directly in front of me, and some are to my left. Some things are in the foreground and some are in the background. This spatial organization allows us to discriminate, from moment to moment, what is currently reachable from what is not currently reachable; it allows us to keep track of things, to come back to them again even if our attention drifts away towards something else in the environment. This organization is relative to my bodily position. There is much to say about the role of one's body in organizing the spatiality of the first-person perspective and the egocentric frame of reference (see especially Merleau-Ponty 1962, 98ff). In itself, however, the environment is not entirely set or stable; things can move or be moved. Water is more fluid than the glass that contains it, or the table in front of me that supports the glass. Imagine if the glass and the table were fluid like the water. Our lives would not only be messier than they already are, we would have a difficult time sorting out one thing from another. The lines of the book I'm trying to read would start to run into the glass of water and start to sink into the table.