Error is a supposition that pleasure and pain, that intelligence, substance, life, are existent in matter. Error is neither Mind nor one of Mind's faculties. Error is the contradiction of Truth. Error is a belief without understanding. Error is unreal because untrue. It is that which stemma to be and is not. If error were true, its truth would be error, and we should have a self-evident absurdity --namely, erroneous truth. Thus we should continue to lose the standard of Truth.
Mary Baker Eddy