Alain considers this for a moment. He's never seen the sea, and his understanding of how rivers flow to it is purely theoretical, but it's enough to understand the metaphor, at least. Some branches trickle out into creeks or dry up in the desert, some become stronger, faster-flowing rivers as they go. It makes a kind of sense.

"But you can't tell which it is from the current," he says, finishing the thought out loud. "Mayhap that's all the difference is. That your friend sees what I only feel."