It's sort of like the question of which came first: the chicken or the egg. Was Ben destined to be an evil person before he entered the temple or was he turned evil only because of the results of the actions of others who weren't even in his past. Hard to believe he was ever an innocent child or innocent anything. It was an interesting acting out of that old time travel question: if you had the chance to kill Hitler when he was a baby, would you do it? Kill a baby who was totally innocent at the time but would grow up to be a monster. Just like good ol' Ben Linus.