Question: Why are a person's principles more important than the law?
Answer: A person's principles are his means of integrating his knowledge about the world. So when we say "principles," we are speaking of both his knowledge of facts in general and his moral knowledge, about what is of value to him and what he and others ought to do in various contexts.
The law is a body of principles that apply to the organization and control of society, especially by use of force. The law should be based on the morally proper ways of organizing society (i.e., the principle of non-initiation of force and the rights that follow from it), but it need not be. Indeed, by this standard, all systems of law in effect today are unjust to some degree. Many are downright oppressive.
It is common to many ethical viewpoints to hold that no one has a duty to obey an unjust law. This was the basis, for example, of the civil disobedience protests of the Indian independence and American civil rights movements. This is particularly true of in the Objectivist view, because Objectivism
holds that there is no higher value for any of us than our own lives and happiness. Our moral principles summarize for us how to achieve this ultimate value, and thus our moral principles offer us more fundamental guidance than does the law.
Similarly, our principles in general summarize what we know about reality. No one can legislate the facts at the point of gun, and so the law does not trump any factual principle we know of. But of course, the law creates some facts, such as the likely consequence that if we murder someone we will be arrested. And in that sense, the law is a fact we must take account of in making decisions.
We may have good reasons to obey laws that are unjust, as long as the injustice occurs within the bounds of an essentially open and rational society. As long as our society is essentially free, the rule of law is itself a valuable aspect of social order, and one we should uphold. But when injustice becomes large and unreasonable, then it can be the case that the value of our lives takes immediate precedence. At the extreme, if one is trapped in a totalitarian dictatorship, one's best interests are clearly served by trying to live and escape however one may. (This is the situation Ayn Rand
dramatized in We the Living