From Oscar Wilde's The Picture of Dorian Gray (emphasis added):
those who find ugly meanings in beautiful things are corrupt without being charming. This is a fault. Those who find beautiful meanings in beautiful things are the cultivated.
What does "corrupt without being charming" mean in this passage?
I would say it refers to the idea of a slick, snake oil-y salesman: corrupt, but corrupt by charming you out of your money. They sort of find the beauty in the ugly things; smooth it all over until it is palatable. Someone who finds ugly meanings in beautiful things isn't charming at all, but they are still corrupt. Thus, the contrast.
I think this passage is fairly straight-forward in the context of the novel. Many of the characters are corrup (that is, enjoy pastimes and activities that the society of that time thought morally wrong), but that was tolerated as long as they were charming. Being corrupt without being charming is a fault.
It refers to a person who sees, say, a beautiful landscape painting and chooses to sneer that the painter obviously doesn't like people.
This is corrupt -- he's ascribing evil motives on insufficient evidence -- and repulsive rather than charming. Wilde is being witty here and saying that being charm is enough to mitigate being corrupt, but these people don't.
"Find ugly meanings in beautiful things." : Tendency to, in an unbalanced way, hyper focus on the newly found bad aspects of a traditionally praised person, place, or thing.
"Corrupt without being charming." : Perhaps the only reason the "bad" was noticed in the first place is because of our own insecurities or unfavorable traits. Regardless, this new found truth is often excitedly relayed to others with the expectation of receiving praise (being charming) but the message is almost always unwittingly delivered in a self righteous and patronizing way eliciting disgust instead.
Think of every "wake up sheeple" person you have met :)
Human beings cannot bear much reality. That is the basic point that Plato was making in The Republic. Thus corruption, which is endemic in human society, is often covered up by charm; this makes the corruption bearable. But nevertheless, as Plato pointed out, it doesn't get at the real root of the problem.
The fault is really two-fold. Lack of real charm; and a surfeit of corruption.
Wilde, by merely focusing on the aspect of charm, was ignoring the corruption endemic to human society; presumably, he thought this unfixable - but I do wonder how he would have considered this after his experience in Reading Gaol.
Corrupt statements made by people who enjoy vices would be charming. A corrupting friend would be charming. A merchant might be charming. However, a person sharing the connotations associated with a beautiful thing fits the author's point of view as an uncultivated person.
