"A certain height. Yes?"
"Another height below that height. Yes?"
"Two different heights. Yes?"
"Co-existent, but not contradictory. Yes?"
"The higher height dependent on the lower height. The lower height not dependent on the higher height. Yes?"
"Possibly; but why not the other way round? The lower height, I agree, seems to exist without the higher. One gets to the higher by reason or pathway of the lower. And so the higher is dependent on the lower, not the lower on the higher. Without the lower we wouldn't get to the higher; wouldn't have a higher. Or so it seems. But perhaps the lower has simply eroded away, in time. Was higher, is now lower. Wouldn't be lower if not for having been higher in the first place. And so the lower dependent on the higher, not the higher on the lower."