On a first viewing of Frozen, there is perhaps no moment more likely to get a laugh out of the whole audience than a little twist near the end of "In Summer." As Olaf the snowman skips through his fantasy of a bright summer field, he approaches a tiny puddle where the snow has melted and gaily declares:
Winter's a good time
to stay in and cuddle.
But put me in summer
and I'll be a — happy snowman!
It's a silly and effective moment. In any group there will be at least a couple of laughs. But a pedantic, humorless poetry teacher might object: the rhyme scheme has been broken! Does this not break the rule of the poetry itself?
Of course, any sane person knows that this is a silly objection. Though one poetic "rule" at play in the song has been broken, this does not hurt the effect for it relies on a deeper art. A stable rhyme scheme has its uses, but subverting the expectations of a pattern with a the right departure is itself a rational option to produce a special effect.
That said, the curmudgeonly poetry teacher might be right if she insists that her students pick up a rhyme scheme and stick to it. Or she might insist they stick to a meter, alliteration, or some other structure. This would be entirely valid, and indeed it might be a failure of her as a teacher if she did no such thing but instead simply told every student to write in free verse all the time.
For the rules exist for a reason. Even if they are not always and everywhere necessary, they are provisionally quite necessary. A poet can learn from the rules themselves how and when to transcend them, but one who never submits to the rules at all will never learn the artistic wisdom which makes such a maneuver viable.
An analogy lies ready to hand in music. If one does not submit to the discipline of their scales and chords and the fixed notes and sheets for practice, save for the odd prodigy, they will never develop the free power to produce something new of a new pattern. Likewise, if they do not compose something with consistent audible tempo, rhythm, and other qualities, there will be no flow which they could intentionally interrupt in a creative flourish.
The principle extends to every sphere of life. If there were no rules of grammar, no jokes could be made by twisting them. If there were no popular sayings, you could not make a point by modifying one. If a mechanic does not develop his competence by strict rules and instructions, he will not have the luxury of trying a creative fix to an unusual problem. If a man does not master lifetimes, ownership, and borrowing in safe Rust, he will only cause Undefined Behaviour if he tries to use unsafe Rust.
Rules create the general patterns and conditions for success and learning. Only by rigorous obedience and practice do we gain the mastery which enables us eventually to effectively improvise. Through the rules we form the skills embedded in the rules so that as skilful agents we might surpass the rules at need.
It is at this conclusion that we find, I think, the hook into Christian virtue and the moral law. Things like the literal wording of the 10 Commandments or the many other specific commands, prohibitions, admonitions, and warnings in Scripture are the rules. It is through faithful obedience to these rules, by the work of the Holy Spirit, that we form the virtues and graces which enable us to become a true human in the image of Christ.
This is the ground on which a faithful Christian will have to stand in dealing with the "exceptional cases." We ask all kinds of questions when we see the extremes of life. What do you do when the Nazis come banging on your door looking for Jews? What about when you enter Egypt and fear Pharaoh will kill your for your wife? And what about when a runaway government pushes for more and more control that they will abuse to everyone's hurt, or you are commanded to submit to controversial and burdensome regulations that might be more harmful than anything else?
In at least some of these cases, the time may come to "break the rules." To tell a lie to save a life: this might be demanded of us. To defy an order or a law in the name of justice: such may sometimes be our duty. It would be a mistake to think that the exact words of some particular commands are the whole story of ethical activity. The essence of the moral life is found in the two great commandments: to love the Lord our God with all our heart, soul, mind, and strength and to love our neighbours as ourselves. The particular commands are the rules by which we learn and become skillful artists in this love. We will not begin rightly to comprehend what love is, how it works, or what it looks like in proper form unless we submit ourselves to the rules and allow them to impart its inner character into our hearts and even bodies.
Yet if we do by the rules learn this skill of love, with all its refracted and coordinated virtues, we may indeed become the kinds of moral characters who can at times set aside a rule by this higher authority. Only the obedient and respectful son can, with sobriety and authority, turn to his father's face and tell him "No" when he begins to play a wicked tyrant. Only if a man has spent his whole life telling the truth even when it hurts can he exercise fortitude and wisdom in sending the soldiers away misled. The man who has led his life by the rules knows their weight, their nature, their meaning, to wit their very essence, so that when their literal forms impede the good they serve, he can, whether by reflection or intuition or both, discern the good that lies beyond them in a time of need.
It is not wise, then, to speak too lightly or too early of exceptions to the commandments, not least when they come from God. Even if we get the right answer to a hypothetical question, it does not mean we would be guiltless in a real situation. To kill an attacker threatening your kids may be the correct choice, but it is of no credit to you if in fact you're a serial killer who has never taken life all that seriously to begin with. There is nothing commendable in a lie to save a life if you would just as soon exchange the truth for a Klondike bar. Neither is there any virtue in ostensibly principled civil disobedience if a man has spent his whole life ignoring the law whenever it suited him or whenever he decided on a whim that a law was of no value.
So we must learn the rules before we are ready to transcend them. Learn the composition before you play unexpected notes. Master your language before you tweak the grammar and the words. And subject your lyrics to the discipline of a rhyme scheme before you substitute "happy snowman" for "puddle."