 Because they operate subconsciously, habits may continue after their original rationale has been forgotten or repudiated. Because they entrench modes of conduct rather than ends in view, they may produce unintended results when the environment changes. We can reliably produce alternative results only by acquiring a new habit. Discovering the means required to change habits requires psychological and sociological inquiry, not just conscientiousness and willpower.  It is magical thinking to suppose that we can change habits through conscious willing, when we lack knowledge of the means of change.  Nor can we check their operation through monitoring, since they operate behind our backs. (HNC 21–32).