I think it's a classic case of not understanding equality, hiding behind enough complexity that it's a bit more complicated than usual. Many people have a hard

I think it's a classic case of not understanding equality, hiding behind enough complexity that it's a bit more complicated than usual. Many people have a hard time not reading equalities as an implication... if there's a mass and an acceleration, then there's a force. But the equality says, it's the same. It isn't an if-then, it is that whereever there is a mass that is accelerating, that is force. The force doesn't "cause" the mass to accelerate and the mass accelerating doesn't "cause" the force; they're equal, they're the same thing, trying to wedge in between the two of them is a fatal error, and a very common one in physics education. Both of those approaches are equal. Or, to put it another way, it isn't that the fast moving air and the slow moving air "causing" a pressure differential which then "causes" lift... it's one integrated process. They aren't separable. You can't have different levels of pressure without some effect on air velocity, you can't have forces in the air without some effect on pressure, etc. The whole argument is all "But what causes what?" and the only correct answer is that it's an equality, not an implication. It can only be properly understood as a single whole that can be looked at in several ways.