The stoics don't believe that we have an irrational beast in us as a part of our human nature. For the stoics, the smos, which they frequently refer to as simply nature, is a rational and divine organism. The stoics wisely realize that our battle with wrong desires begins with assent to things and events in nature. If we judge externals, things that are not completely up to us, as either good or bad, we open the door to desires and aversions that will easily overwhelm our will.