First of all everyone should know this answer. But in case you don't know sometimes someone as in your classmate can be allergic to any sort of animal. Sometime it just depends on the kind of pet. If it was to be a dog then there are quite a few reasons. This question is fairly easy to answer.
In The Crucible, certainty can be dangerous as demonstrated by the character of Abigail.
She accused Proctor's wife of being a witch. She testified that she saw the spirit of Proctor's wife and it stabbed her. Even though she lied, her certainty in front of the jury and the towns people convince them that what she said is true and that Proctor's wife is a witch that must be burned to death.
