Duality in Medical Madmen

Dr. Lanyon
In the final two chapters of Jekyll we are given the accounts of Dr. Lanyon and Dr. Jekyll.  Dr. Lanyons telling of his role in the strange accounts tells us of the shock of learning the true nature of even our best friend.  In this case the shock is so great that Dr. Lanyon is beyond recovery and later dies.  His tale recounts the mysterious nature by which he is given intimate knowledge of his long time friends condition.  Upon finding that the murderer, Mr. Hyde, and his long time companion are one in the same, Dr. Lanyon cries out to God in horror.  It would seem fitting to note that the duality witnessed in Dr. Jekyll and Mr. Hyde resembles closely the same duality presented in many modern religions.  It leads one to question whether it is better to truly know those we are close to, or to have some level of privacy?  Also, who does this privacy actually protect, the individual in question, or all of us?
Dr. Jekyll
Dr. Jekyll tells us of his attempt to separate two distinct selves in his experiment.  He is trying to separate the truly good, Dr. Jekyll from the truly evil Mr. Hyde.  He succeeds in separating the two selves, but indicates that he is left with his truly evil self, and the same conflicted former self.  In his actions, he has not created two opposite beings.  He has merely freed the most course part of himself from the constraints applied by the moral conscience possessed by Dr. Jekyll.  In part I find myself wanting to blame Dr. Jekyll for freeing his darker self, but there is something entirely human in his confession.  His predicament questions at which point our misdeeds cross lines at which we all may not come back?  I see a slippery slope argument in his onset of evil.  Once he began down his path he seemed powerless to turn back.  In seeing Utterson's drinking increase, I question if Dr. Jekyll's undoing will not be the undoing of, not only Dr. Lanyon, but Utterson as well?