This is probably the most important commandment we can include since it addresses the core problem with religious commandments: it allows us to discuss these commandments and REJECT them if need be. Rejecting the idea of absoluteness is something we need to include.
By saying this, you make it clear that the Onus of Evidence is on the person making a claim. It also silences emotional arguments with no empirical basis; Allowing data to guide your reasoning to Logical Conclusions.