Picture a man and woman, devoted, loving, trusting, loyal and kind. They love their children, their nights are filled with kisses and caresses and passion, and their love makes them happy, productive citizens. A perfect picture, no?

Now suppose you learn one more detail: these two lovers just happen to be brother and sister. Doesn't look so sweet anymore, does it? You have just taken a crash course on an important moral issue: the issue of incestuous rights.

Once widely condemned as perversity, incest is coming out of the closet. After all, if not involving minors or coercion, incest is a private activity between consenting adults, directly harming no one. The incestuous community is not a homogeneous "Other" ; there is great diversity within it. With birth control, incest will not pollute the gene pool, and being incestuous need not affect anyone's competence. There are even historical figures: Lord Byron (attracted to his half-sister Augusta Leigh), the Haps burgs and the daughters of Lot.

But all this misses the real issue: whether incestuousness - by which I mean a propensity to feel sexual love for members of one's own biological family - is morally acceptable. It is overwhelmingly clear to me that it is not, that it is very, very wrong. This is so clear that it almost defies explanation. Still, in today's climate an explanation is crucial.

Incest is so repulsive because it is a perversion of a beautiful ideal. There is nothing more sublime than the deep bond of romantic love between man and wife, but incest is a terrible mockery of such love. It's not just a minor flaw either. The addition of incestuousness poisons the entire cocktail, and it becomes as horrible as it was beautiful before. All the tender care, loyalty, laughter and everything else only makes the incestuous relationship more twisted.

Nor is incest a mere extension of familial love. It is noble, right, and good for a brother and sister to love each other with great devotion, to touch, embrace, and share secrets and care deeply for one another. But the instant you add a sexual component (or even a merely romantic one), each aspect of that goodness at once becomes an equal and opposite aspect of horror, of anti-love.

That is my judgment (and I am not alone). Obviously, I consider incestuous feelings morally wrong. If I ever feel any myself, I will fight to overcome them and will never yield to them. It is not "denying oneself" or "living a lie," but resisting temptati on, trying to improve one's character as we all should. (And by the way, we can indeed judge incest without being incestuous, as we can judge pedophilia.) I will strive to treat incestuous people with compassion, although the "proudly incestuous" make it quite difficult.

As for the law, I oppose incestuous marriage, child custody, and school curricula. No one, in my view, should ever be forced to act as if he believed that incestuousness is OK (and I mean no one: no church, no employer, no teacher, no landlord, no student ). I don't think my stance makes me narrow-minded or bigoted; nor does it make me patronizing or hateful toward incestuous people. I merely disagree, strongly, with their "inclusive" idea of romantic love.

Of course, one could say all this begs the question of why incest is perversion. I believe it violates a basic moral law existing entirely apart from human existence. Is that a proof? Well, no. Strictly speaking, I cannot prove incestuousness is wrong. Bu t then, we can't "prove" that anything is. Why is rape wrong? Because it violates a basic right to privacy. A "right"? What's that? Can you prove rights exist? And then you draw your gun and tell Mr. Rape Fan to stay the hell away from the women you care about.

In the end, it comes down to very fundamental propositions, and the scary thing is that with enough early exposure to incestuous people. I might well have become desensitized to it, losing my ability to see the twisting for what it is. But the truth that incest is wrong is crystal clear to me. Incestuous-rights supporters may claim that their opponents just do not know enough about love. To my mind, though, the opposite is true. No one who supports incestuous rights has any idea what true love really is. If you have incestuous feelings, get help. And if you believe as I do, then take a stand, and in the name of true love, say "No!" to incestuous rights now.

John Keisling's new book, a collection of his 54 Wildcat columns plus nine others, is available from the author, a math Ph.D. candidate. Please e-mail keisl@math.arizona.edu or call 325-0351.