Water

It is no curious thing that water is clear, unless polluted by such things that would discolour it. Of course, when polluted by those things that would not discolour it, it is still clear: so we have a situation where water, unless unpolluted by such things that would, or would not discolour it, is clear. Which brings us nowhere if we just need to know whether we can drink it.
A fast flow traps air, which rises in a panic to join molecules of its own king - up there, in the air. A metaphysical refugee, fighting the influx of molecules which not only displace it, but do so with the utmost transparency, so everyone can see what's going on.
They say water can mean purity, but not when they are talking about water torture.
Although, apparently, elsewhere they have said drowning is the most peaceful way to die - so if you're in a hotel room that's on fire, with the mattress coughing out carbon monoxide, which drifts across, nice and easy, ready to put one over you and sleep you to death - jump in the pool and breathe deeply - it'll be much more relaxing. We humans, if we have no control over our destiny, we have nothing.
And nothing returns us to the question of transparency, and what's in it for us. Sure, we can see through clear water, but that doesn't mean it isn't loaded with something. It also doesn't mean that we care. Just because the water's transparent doesn't mean I was even looking for it. I could argue for days the benefits of transparency in water, while I continue to drink diet Coke.
I'm not even on a diet, I tell myself. But I do eat. Which, I suppose is no more than a modern day oxymoron (a word whose meaning is rapidly changing to describe TV audiences in the early 21st century. Or should it be polymoron?)
Like the transparent water, we're happy everything is pure, so long as we don't have to taste it. Even when we see those bubbles rising rapidly, and with some violence, it won't bother us, so we might as well just get on with it.