Dear Barb,

What a great question! Steve Messer, who's head of Homeopathy at the Southwest College of Naturopathic Medicine, has a lecture out on this subject on tape which you can probably buy at
www.minimum.com but here's what he says:

The common symptoms get you to the group of maybe 10 or 20 remedies that historically have been known to treat a particular problem--like a fever, for instance. It's common sense that your remedy will have to be able to cause a fever in a healthy person in order to cure it in a sick person. But then which fever remedy?
What's peculiar or individualizing about your fever? Maybe you're thirstless during your fever; well that's very peculiar. So you go to the repertory and look up
Fever, thirst, little thirst-ars., gels(2),
puls(2). So, from over 100 remedies in the main rubric, you're down to 3, just cuz you were able to find a peculiar symptom.

Barb, it's just that the common symptoms make too many remedies show up.

Sometimes it's the modality that's crucial--the person's better in the fresh air, or needs to lie down, or needs company, or is restless, or < on least motion. These things are very important to us. Or the aggravation time; or keynotes of a remedy. If you see a keynote of a remedy in a case, it's a real blessing. Like, the problem started on the left and moved to the right--Lachesis.

Hope this helps,
Snoopy