I was just offered "a water". A woman walked down the corridor in the place I'm working today, carrying a tray stacked with bottles of water. "Would you like a water?" she asked.
Bottles of water. Bottles. She wasn't offering me water. She was offering me a bottle.
When we describe a something, we describe something limited, a thing unto itself. We talk about a ball, because the ball has round edges that separate it from the rest of the world. We talk about a house, because it has walls that define its borders.
We don't use the word a to describe a field of substance, or a mass of stuff. Gardeners don't prepare a soil, though they do prepare a bed of soil. We don't inhale an air, though we often take a breath of air.
We can't walk into a nature, though we can go into a wilderness. Nature is a form of being that exists with or without human beings. A wilderness is contrived by humans, even in its wildness.
It's this distinction that makes me uneasy about having "a water". "A water" is imprisoned, diminished. "A water" doesn't flow.
Water leaks into us and out of us. It changes shape. It escapes high and low. It thaws. It evaporates.
I don't want a water. I want water.