A person's crux for holding a view on some topic is any belief on which those views depend, such that if the person ceased to have that belief, they would no longer hold the view. For example, a crux for someone who works in AI safety might be the belief that transformative artificial intelligence will arrive within the next few decades: ceasing to have this belief will cause the person to work on other causes or problems.^[1]

A related concept is that of a true rejection, or a person's crux for rejecting a view. Often, what is raised as an objection is not a true rejection, because the critic would still reject the view even if the objection was fully addressed.^[2]