McLeody Day

The reason Charles Norstadt can grow to trust in McLeod is because McLeod was the only fatherly figure that Charles had in his life.  In the movie, Charles sees McLeod as a scary cave dwelling monster that hides himself and his scars from the world so that he can write pornography.  Norstadt did not see any form of companionship in this "monster" because he did not take the time to get to know him.  Charles used the memory that he had of his father, a heroic death in an Air Force battle, as inspiration for how he wished to influence his life.  During the same time, Charles began taking tutoring lessons from McLeod and begins to learn more about his perceived "monster."
The townsmen and children never took the time to know McLeod and so began to cloud their minds with unjustifiable preconceptions.  They believed that McLeod scarred his face in a fire or that he was born with his scars.  There were many rumors as to his occupation, some involving pornography.  Charles had never truly met McLeod, except one unfortunate encounter involving the dog Mickey, and had nothing to counter these rumors with, so he accepted them as truth.  These rumors would begin to fog Norstadt's mind and make him vigilant for any sign of confirmation and make him seek the truths behind the rumors.
After the various tutor sessions, Charles began to knock out each preconceived falsehood, one by one.  He learned that McLeod is a secluded artist who has designed the covers of some popular magazines as well as painted some amazing pictures- that pornography had no place in McLeod's life.  McLeod even trusted Charles with the story behind his scars- that there was an old car accident where a boy lost his life.  In return for McLeod's trust; Charles trusted him to tutor him and not beguile him like a monster would.
Out of these tutoring sessions, each person would gain something- Charles would receive a father figure, someone he could trust in a life where it seemed like everyone was against him; Justin McLeod would receive his shot at redemption, a chance to show the world that he was still a person, that he never did molest the boy who died in the car crash, and that his scars do not make him a bad person.
It is McLeod's chance for penance that drives him to father the boy, to give him nothing but friendship and success.  He had to prove to someone, whether it be a little kid or not, that he was not a "monster to children" and that he had values.  He did not want to tell Charles the answer because he wanted Charles to truly believe that he was a good person and that he did not molest children.
Charles very truly does not believe that McLeod did any of the things he was accused of (except involuntary manslaughter).  He believes that McLeod has been there for him and that he would always be.  This is what Charles needed in his life.  At home, his mom did not believe that he would amount to anything significant and that he needed to stay local to avoid degeneration.  His sister tore down the heroic father that Norstadt believed he had and replaced it with an insane, drunken reprobate who was admitted to asylum where he eventually killed himself.
That gap in Charles' life was gradually fulfilled by McLeod.  At first, it would appear that all Nortadt wanted was to pass his test, but as his life digresses Norstadt's hero position opens up and is easily taken up by McLeod who had done fatherly things with him like taking him hiking and flying.  The hole in McLeod's life- his past convictions was fulfilled by Norstadt, likewise.  Justin needed to feel like he was still something in the world, that he could still do good by teaching this boy and showing people that he was not a child molester.  If he was going to prove it to the world, he first had to prove it Norstadt.  He had told the world many times that he did not do it but no one believed him so he did not wish to tell Norstadt but rather make him believe.
My one question with the whole morality in the movie is, what is it worth?  Why does McLeod have to prove his worth to a world that already rejects him by default?  I understand he would like for things to go back the way they were- with his wife, teaching career, etc. but all those things are already gone.  There is no point in fighting for what is already lost.  It is unfortunate, but true, his scars will lower him in the eyes of other people and if he was already content with living his secluded life, why would he trouble himself further?

Recognition

One of Socrates' teachings was that everybody knows virtually nothing and that it is impossible for one to count as knowledgeable.  Where one everyday person might be an expert in mechanics, he would make a physicist look like an idiot when it came to fixing cars.  But Socrates also went a little deeper and always asked, "why?"  He realized that it is impossible for someone to know something in its entirety.  We may think we know something all the way down to its roots but there is always the never-ending "why?"
Therefore, to know something, means to recognize it.  To recognize an item means you are aware of its boundaries as well as its potential and how it relates to you.  We may think we know someone entirely but there will always be something out of our reach of comprehension.  We won't be able to understand and prove why this person does the things he or she does.  However, we recognize that person and all that we associate with him/her.  So if this hypothetical person does something others would view as strange- we might see it as perfectly normal because we recognize the limits of this person and we would be able to understand their actions because of our deep recognition.
To make Socrates proud, being knowledgeable means to recognize that we know nothing at all.  No one person will ever know every fact ever.  Like the earlier example, I may know tons of stuff about physics and science and math- enough to outsmart the "Average Joe" plumber; but once it comes to pipes and such- the plumber is clearly superior.