“The foundation of the whole system is standing on air."
(Hilbert's famous slogan "We must know, we will know". Hilbert tries to demonstrate the wholeness of mathematics)
【Kurt Gödel】 incompleteness theory (against Hilbert)
no matter how much data you have, there's always statements that is true but can not be proved.
One step further:
【Turing】
There's always some problems that cannot be solved,
We even don't know what is provable and what is not. There's no way of telling which is the unprovable things.