A discussion with a friend highlighted our differences of opinion on the subject of jealousy. I was bemoaning the fact that her friend, a guy I am positive I could get along with, never responds to anything I write to him because he’s not pleased that I make comments on his wife’s Flickr. She was asserting that his jealousy was a good thing. She was thrilled that her own sense of jealousy had returned, long after the end of an unhealthy relationship.

This left me aghast. To me, jealousy is a worthless and destructive emotion, something to be gotten under control, like the desire to cause violence or revenge.

Here are the pros the way I understand them:

1) It shows you care.

This is a popular interpretation I’ve heard before, exclusively from women. There are much more worthwhile and positive ways to show you care, like changing some disagreeable aspect of your lifestyle to make her happy. I know — it’s easier to get angry about things. But relationships require effort and commitment.

2) You can defend your wife against would-be seducers or other threats to your relationship.

This one is just silly. Seduction is the art of getting ill-advised consent. If you feel that your wife is in danger of giving consent to an outside party, your beef needs to be with your wife, not the seducer. Similarly, if there are external threats to your relationship, your relationship needs to be fortified from within.

I actually think that’s it for the pros. Now the cons:

1) Interferes with judgment.

Jealousy invariably obscures the truth of any given situation.

2) It can put a premature end to what could be a rewarding friendship.

Stop wasting time giving me the stinkeye; I’m no threat and maybe we have some rewarding commonalities.

3) Jealousy is a euphemism for insecurity.

Jealousy is a threat response and consists of a combination of insecurity and anger, two emotions that many people pay good money to manage, for good reason.

4) Jealousy is always pointed in the wrong direction.

Merely a variation on these other axioms is the assertion that jealousy always points to an external threat when the actual problem or potential problem lies within the relationship. This applies to all kinds of threats — people as well as other attention-suckers like work or hobbies. If the relationship is so rewarding that your significant other is willing to risk reprisals at work or slow progress in some other activity in order to be with you, then it’s pretty much like when you were first dating! So don’t get upset at the work, the hobby or the pretty secretary who spends too much time with your S.O. — work to figure out what would make your S.O. more interested in being with you.

5) It is a tremendous waste of energy.

All that fear, anger, suspicion — all the conflicts it causes, and stupid fights: “What are you so upset about, he’s just a friend!” — these are an exhausting burden to live under, and poisonous to the people around you. The damage it can cause when you get it wrong — good relationships get torn up by groundless suspicion all the time.

Here’s the bottom line: If you’re secure in your relationship there is no need for jealousy. If you’re insecure in your relationship you need to work to fortify it. In either of these cases any jealousy is always misdirected and needs to be controlled like any other ugly, base instinct.

OK, comment away.