jim the reason you do not see any reasons given for we need to define atheism without defining the scope as well is that nobody has even suggested that you know what else you don't see any reasons given for you don't see any reasons given for using giraffes instead of horses to pull carriages nor do you see any reasons given for wearing shoes on your hands instead of your feet i assume you're not doing this intentionally but you're making what's called a straw man argument and it's not the first time you've done it please be more careful as logical fallacies whether deliberate or accidental in addition to irritating others tend to impede obstruct progress and i assume in good faith that neither one of these is your goal talk