When Kas Thomas asks the question "Which came first, life or Earth?" in today's lesson, he is not asking a trick question. Well, it's sort of a trick question because we cannot answer it, and as Thomas points out, "there is not only no consensus view on the subject, there is not even any consensus on which of the many available candidate theories deserve to be candidate theories."
According to one potential candidate theory, for instance, life must have originated before Earth was formed, since it didn't have enough time to develop here.
This all speaks to the tendency we have to think science knows more than it knows. Not only do we have knowledge gaps here and there, Thomas points out, we have gaps when it comes to answering fundamental questions about how life arose.