Raskolnikov invents a test to find out whether he is a great man, then takes it, and the taking is the failure.
The theory first. Ordinary people must obey moral law. Extraordinary ones — Napoleons, lawgivers — may step over it, and their conscience will not punish them for it.
So he murders a pawnbroker. Not for the money. To learn which one he is.
He steps over, and then he breaks. Fever, terror, weeks of it. By his own rule a great man wouldn't suffer, so the suffering becomes the verdict.
Dostoevsky's genius is that he never argues the theory down. He just lets it run, and we watch the idea destroy its own author.
Anyone who needs to check whether he's Napoleon has already answered.