Moriarty is Not Holmes' Greatest Adversary
Okay, hear me out.
Moriarty is a formidable opponent to Holmes, yes. In fact, Holmes and Watson have to take a totally calm and relaxing sightseeing trip across Europe to escape him. But at least Holmes had a plan; it was solely his logic against Moriarty's logic (and maybe a bit of martial arts in front of the Reichenbach).
But Moriarty doesn't hold a candle to Baron Aldebert Gruner (from 'The Illustrious Client') and Charles Augustus Milverton. Let me explain.
Even though Holmes detested Moriarty for everything he represented, he respected the professor as well. I think he even refers to Moriarty as "esteemed" in an unironic way in one of the stories (it was either EMPT or FINA, I'm not sure). But the case still stands. For the first time, Moriarty was well and truly his equal, so much so that Holmes would like to retire if he defeated him.
Yet Gruner and Milverton are different. They don't have criminal organizations; they aren't masterminds. They just revel and profit off of the suffering of other people. It makes them the vilest antagonists in the canon--Holmes knows this too. When he faces the both of them, he doesn't outwit or outrun them, like he tries to do with Moriarty. They are past outwitting or threats; not only do Gruner and Milverton make people suffer, they do not see what is wrong in continuing to do so. Therefore, Holmes resorts to burglary to try and stop both these men, because he is stumped. Even with his great brain, he cannot understand how Milverton and Gruner can be so commonly, if not casually, evil; as a last resort, he tries to stop them by taking what is incriminating (Gruner's disgusting 'book of women', Milverton's blackmail letters).
So Holmes' treatment of cases in ILLU and MILV are important; but I also want to draw attention to Kitty Winter and *that* unamed woman that turned Milverton into a piece of swiss cheese, because they are a) underappreciated favorites of mine and b) they also show a lot about Holmes and subsequently his attitude on Gruner and Milverton.
Holmes does not seem to mind that Kitty Winter threw a bottle of acid in Gruner's face. Neither does he mind that *that* woman did her swiss-cheese thing. In ILLU, it is mentioned that he defends Kitty in order to get her the lightest consequences for the acid-throwing, and he straight-up destroyed all of Milverton's blackmail papers. Holmes does this not only because he tends to go by his own moral compass in cases such like this, but he also recognizes the gross wrongdoing of his adversaries. This, I think, is what make the Holmes stories so special to me: it's not just about a genius defeating evil. It's about a man with a peculiar brain and an uncanny knack of observation, a man who is distant and lonely at times; but whatever happens, he'll always stand on the side of the wronged, even if society deems it otherwise.
