It all depends on your ability to model things. In the case where that ability is perfect (which may not exist,) all the "macroscopic" elements of reality you

It all depends on your ability to model things. In the case where that ability is perfect (which may not exist,) all the "macroscopic" elements of reality you recognize are as true as their "microscopic" elements. That is, if your model of a fluid is perfectly correct in respect to individual atoms, then proving something about atoms automatically proves it to a fluid. If you prove that atoms exist then fluids exist (if your model is perfect.) This problem is already tackled by science. In physics, models are known to be limited and target only a simplification of reality, and they become greatly wrong in special cases and thus unacceptable. For example, modelling a ball thrown in the air neglecting air resistance may be "correct" enough when it is a lead ball, but will become apparantly unacceptably "incorrect" when applied to a ping pong ball.