Scholars continue to debate whether the U.S. Constitution adopted a particular interpretation of the "rule of law," and if so, which one. For example, John Harrison asserts that the word "law" in the Constitution is simply defined as that which is legally binding, rather than being "defined by formal or substantive criteria," and therefore judges do not have discretion to decide that laws fail to satisfy such unwritten and vague criteria. Law Professor Frederick Mark Gedicks disagrees, writing that Cicero, Augustine, Thomas Aquinas, and the framers of the U.S. Constitution believed that an unjust law was not really a law at all.