And that's fair enough - it's a possible way to see him - but I don't think it undermines the real heroism I'm pointing out, does it? Even if it's true Severus has no 'feel' for right and wrong, he steadily fights to do right; what's more, he usually succeeds.

My Snape isn't quite yours, as you'll have gathered, and I'm not sure which of us is closer to Rowling's, but there's no doubt this character is a hero, after his fashion.