Is He Cheating Us by Picking These Examples?

Is this supposed to be a general message to us about the nature of reality, if it's not just about rivers? And if it is supposed to be ani frence from, perhaps, from the fact that sea water is poisonous for men and healthy for fishes. So you might think that what he's observing there is not so much some kind of awful conglomeration of reality, but something about the way we think about reality. The very practicality of the examples makes it see that, once again, if he's speaking to an audience,. i'm really in trouble here.