After a judge has made the first ruling on a particular point of law, judges must follow that precedent if the original ruling is not contrary to the basic moral values of society.
Principle
Orig ruling not contrary judges must follow to basic moral values → that first ruling of society
No precedent + ←→ abide by own views judges views don't when deciding contradict broad public opinion
Evaluation
Gross. They gave us two rules, one of which is bi-conditional (signified by "when and only then").
One rule deals with how you judge when there is a precedent. The other deals with how you judge when there isn't a precedent. So as we look through these answers, we'll first check whether we're dealing with a situation in which there is a precedent, in which case we'll use rule 1, or whether it's a situation with no precedent, in which case we would use rule 2.