I want to start with The Hobbit, a children's story, so we can built up a picture of disobedience in Tolkien's world paralleling the stages of moral development I mentioned earlier.
And it is vindicated when Bilbo's Tookishness gets the better of him, and again in disobedience to common sense and social expectations, he joins the dwarves on their adventure.
Bilbo's very act of mercy is a disobedience to the promptings of justice and common sense, which places it at a higher level of morality, and this perhaps is why it leads to a good end.
But the really important act of disobedience within the confines of The Hobbit is Bilbo's concealment of the Arkenstone against Thorin's very specific orders and threats.
So in The Hobbit, the majority of disobedience is to simple things like fairy-tale rules and the rules of etiquette and courtesy.
Moving on to The Lord of the Rings, we find ourselves in a world at war, and the acts of disobedience and their consequences are both more meaningful and more clearly defined.
First let's look at a few acts of disobedience that spring from questionable motives.
Pippin at least has the chance to mature and redeem himself with later acts of far more purposeful and meaningful disobedience, as we shall see.
The most interesting and fruitful acts of disobedience in The Lord of the Rings result from what one might term the virtue of caritas, or what Lewis called gift-love (The Four Loves 213): love for one's friends, a desire to keep others out of danger, and an urge to trust even where one was told not to.
There are also two major points in the plot where caritas for a superior prompts deliberate and knowing disobedience to his orders.
Giving trust where one is ordered not to is another disobedience that is a direct result of caritas.
In the Chamber of the Sammath Naur we find two overwhelming urges to disobedience locked in battle.