In his 2008 book, Just Courage, Gary Haugen, a lawyer by training, describes an interesting legal precedent known as “void for vaugeness.” Haugen used the precedent to illustrate how vague ideas of Biblical justice can be, and thus why many Christians struggle to know how to apply principles of Biblical justice in their own lives. However, the principle for preacher/teachers is helpful for any topic that suffers from a lack of clarity: if we don’t understand something, we are likely to avoid it.
In law school they taught us that certain laws could be declared “void for vagueness.” This is the eminently reasonable idea that a citizen cannot be expected to obey laws that are too vague to understand. In other words, a legal requirement can be rendered void if “persons of common intelligence must necessarily guess at its meaning and differ as to its application.”
Accordingly, if I got hauled into traffic court for having violated the road sign that said “Drive Appropriately,” I might argue that the posted regulation was simply too vague to be fairly enforced.