Is everything debatable?

Near the beginning of this semester, in my macro principles class, we were talking about all the reasons why economists might disagree. Belief in different theories or methodologies, differing interpretations of evidence, and differences in values or priorities: these pretty much capture everything, I think, although you could elaborate on each of these and delineate subcategories. During this discussion, one of my students asked, "So, in economics, is everything debatable?"