Kurt Gödel spent his life on the formalisms of abstract reasoning, and he arrived at an uncomfortable place. His incompleteness theorems ended a hopeful idea: that any true statement could be traced back, through a chain of theorems, to a set of known axioms. Call a system complete if every statement inside it can be shown true or false using only statements also inside it. Gödel proved that a consistent system of logic always contains truths it cannot prove on its own. To settle them, you have to step outside.
Sit in a train at a station, watching the global. The train next to yours starts to move, and for a moment you cannot tell which of you is moving. You decide only when the last car passes and the still scenery comes back into view. For that moment you were inside Gödel's first theorem. Your system, limited to the sight through the glass, could not resolve a statement about itself. The answer came from outside it.
I think ethics works the same way. Take a system where "one should help another" is true and "one should harm another" is false. The analogy says such a system is incomplete. It needs something external to close it, and that need looks a lot like an old human longing for a higher power.
Religion supplied that external first. For the believer, the words of God are axioms, and any action can be traced back to His intention. The modern man finds this unsatisfying, too much belief and too little method. So he reaches for reason instead, for determinism, for the promise that knowing the cause of a thing fixes its moral weight. But this is the same move. We have only swapped one worshiped external for another.
The theorems do not hand us an answer. In the short span each decision allows, there is still a feeling for good and bad, and it is never quite enough. The choice remains anyway. Either you do it, or you don't.