Consequences. Those aren't specific to magic but magic can give a different perspective most things can't. Cassandra uses it right for the most part and it's helped us do good but we come across those who don't and it's an uphill battle.
One thing I do know is it's one thing to believe you'll act a certain way in a situation but you never know until you're in it because the perspective looks dramatically different on the other side. Maybe things go the way they do because the witch wasn't the only one who saw things needing to happen a way.