When human law, the laws brought about through human government, disagree with natural law, then the human law is no longer a law that should be obeyed, but it is a corruption of law. Aquinas believed that “an unjust law is no law at all.” By this, he is relying upon Aristotle’s metaphysical doctrine that to understand what a thing is one must understand its function. For example, a knife that does not cut is not a knife. Similarly for Aquinas, a law that is unjust is not a law because the function of law is to promote the common good. Thus, an unjust law is a corruption of law since it does not promote the common good.…
