Topics Existence

Question I've always thought it odd that rivers are said to have a single "source". Isn't a river the result of all its tributaries? What gives one source priority over the other tributaries to a river? Isn't the distinction mostly made-up?

Accepted:
July 19, 2012

Comments

An interesting question. Start with an artificially simple example: a stream system with the branching structure of a simple "Y." If the two upper parts were equally wide/deep, equally far from the intersection point and at more or less opposite angles to the lower stream, it's hard to see why we'd say that one was a mere tributary and the other the main stream. If one of the upper branches started much farther from the intersection, and was much wider/deeper at that intersection we'd likely say that the other branch was the tributary. Other cases might be harder to classify.

All this suggests that there's a strong element of convention in the river/tributary distinction. But there's a caution. If we asked a relevant expert — a hydrologist — s/he might have things to say that wouldn't occur to casual observers such as you and I. Whether there's a more interesting distinction that hydrologists make between source and tributary for real-world rivers is something I can't say; my knowledge of hydrology doesn't go much beyond the meaning of the word. The caution here is just that there could be more to the matter than meets the eye, and an appropriately modest philosopher will admit that, absent some real empirical knowledge, philosophical analysis by itself can't give us the answer.

Question I've always thought it odd that rivers are said to have a single "source". Isn't a river the result of all its tributaries? What gives one source priority over the other tributaries to a river? Isn't the distinction mostly made-up? Accepted:July 19, 2012

Question I've always thought it odd that rivers are said to have a single "source". Isn't a river the result of all its tributaries? What gives one source priority over the other tributaries to a river? Isn't the distinction mostly made-up?

Accepted:
July 19, 2012