A friend of mine and I were discussing something that I experienced while studying abroad in college. Sadness. The discussion focused on my thesis that "sadness has an unexpected seductive quality that consumes its victim." Almost immediately we agreed on the premise, and moved on to the cause of this appeal.
We discussed the uncommon emotional depth that sadness allows people to experience, and how this, typically illusive, level of passion is easily intoxicating. Basically said, people enjoy strong feelings, and they don't come around every day. I would go so far to liken its intensity to love; after all, all the victim need do is fixate on the motivation.
That brings us to our next cause: clarity. Revolutionaries have clarity; religious zealots have clarity; activists of all kinds have clarity, and in a romantic sense, they are all very appealing because of their clarity. They motivate us with their clarity. They seem to drive their own passions with it. Sadness, too, has clarity - clarity in emotion and clarity in subject.
Soon we moved into the idea that sadness is like a drug that society readily consumes. Music that is depressing sells spryly. Movies with sad overtones, books on tragedy, the nightly news - they all feed our sadness fix. People seem to dedicate themselves to sadness, while happiness (or at least gayety) is typically dismissed as fickle, and considered passing.
Finally, we discussed the concept of "is sadness is a good." Naturally we were built with the ability to experience it, but was that intended for us to have a clear contrast to a time without it? Was it a tragic result of a terrible fall? We were lead to agree that sadness had no place in time before the fall, and clearly has no place in time beyond the temporal.
That said, it is paradoxical that sadness has intoxicating qualities. Rather, something derived from disaster, and contributing to pain, has certain qualities that actually encourage its consumption. Society seems to be a junkie for sadness, while endlessly questing for peace, joy and happiness.
Or, perhaps, sadness is another characteristic intentionally endowed to man, to allow him to experience the full breadth of his potential. More than merely emphasizing happiness, sadness seems to serve us in too many ways to be discarded. It seems to have a value; it's difficult to say it is bad, but it just seems too far a leap to say sadness is a good.
Roughly, sadness serves us in mourning, lamenting, repentance, dissatisfaction, acceptance of the unexpected, even the unacceptable. Sadness seems to have medicinal qualities that induldged seem to mend us. The last thing I would want to say is that sadness is "good," but I think it would be safe to conclude that it seems to have a valid function.