One or more propositions will be are essential for the contention to continue. They should be asserted explicitly. They are called the premises of the argument. They are the clues (or reasons) for acknowledging the contention and its conclusions. (The saying "obviously" is often examined with doubt, as it can be utilized to threaten other ones into acknowledging dubious premises. If certain thing doesn't appear conspicuous to you, don't be aghast to inquiry it. You can habitually state "Oh, yes, you're right, it is obvious" when you've learned the explanation.)