As I've said before, I don't really like James. And I'm not hating on Snape. I'm really not. I know you're really used to people loving James whenever they criticize Snape but you need to understand that James is not a character I like in the first place. I've told you this.

About Snape not being a blood-purist: If you say so, I could see that. I think there's evidence of him feeling like that but not prioritizing it, but I can accept that it was more something that sort of rubbed off on him and didn't stick around.

Slughorn thought he was the one who taught Tom about horcruxes but he was wrong. Dumbledore knew better too. The thing Dumbledore needed was confirmation about the number of horcruxes Tom made, which is what he talked to Slughorn about but that conversation isn't what made him do it.

You said Slughorn enabled Tom making horcruxes. That's what I was addressing, because it's not true. He didn't know Tom had made one at that point(the memory) and when Harry first defeated him Slughorn was sure he made none. He didn't know until Tom came back. I was never disagreeing about whether Slughorn withheld crucial information.