I leave you this fine evening with a column by law professor Randy Barnett. Professor Barnett commits a classic fallacy. He infers from the fact that not all precedents should be upheld that the doctrine of stare decisis, or respect for precedent, is "empty." This is like saying that there are only two possible normative ethical theories: absolutist deontology and consequentialism. If absolutist deontology is rejected, then one is left with consequentialism.
The obvious objection to this line of reasoning is that the disjunctive premise (i.e., the alleged dichotomy) is false. There is a third normative ethical theory: moderate deontology. The doctrine of stare decisis requires that precedents be respected, or taken into account in one's deliberations. This means that some weight must be given to the fact that the law is settled. This doesn't mean there is no weight on the other side of the scale. It means there is weight on one side of the scale. One respects precedent when one says, "The law in this area is settled, so there is a presumption against overruling previously decided cases; but in the case before me, there are weighty considerations on the other side, so the presumption against overruling is overridden." A precedent can be respected even when it is overruled, just as a commitment can be respected even when it is broken. (If I break my promise to you in order to save a dying person, I haven't disrespected or disregarded my promise. I have concluded that my duty to keep my promise is outweighed by my duty to save a life. The promise had weight in my deliberations, just not enough weight in this case.)
Judges differ in the weight they assign to the doctrine of stare decisis. No judge assigns it infinite weight and no judge assigns it zero weight. But that leaves a lot of room. Ceteris paribus, conservatives assign greater weight to precedent than progressives do. (I'm speaking here of legal conservatives and progressives, not necessarily political conservatives and progressives.) Two judges who respect precedent can rule differently in a given case, because (1) they assign different weights to precedent and (2) they put different considerations on the other side of the scale. Do you see Professor Barnett's mistake? He thinks that because the doctrine of stare decisis doesn't have infinite weight it has no weight at all. Put differently, he thinks that unless the doctrine of respect for precedent is absolute, in the sense of being exceptionless, it is "empty." Professor Barnett needs to read W. D. Ross's The Right and the Good (1930). He might also profit from a logic course.