The revelation was shocking: A good friend said he supported legalized abortion because it reduced the number of children who would face bleak futures in the nation’s cities.

That moment 25 years ago helped crystallize my perspective on medical ethics: Every human life is of immense value and dignity. I could not then, and cannot now, judge whether any person I know should never have been born.

I recalled the conversation as I walked through the Maltz Museum of Jewish Heritage and its new exhibit, which traces the rise of the eugenics movement in the early 20th century to its horrific expression in the genocide committed by Nazi Germany.

“Deadly Medicine: Creating the Master Race,” on loan from the U.S. Holocaust Memorial Museum in Washington, D.C., reveals how several countries sanctioned forced sterilization and, in the case of Germany, abortion and mass murder to try to create a genetically “pure” population.

The history lesson in the exhibit opening Tuesday shows how critical it is to value every human being as we steer a moral course amid the temptations offered by advances in genetic engineering to create a new master race.

Throughout the world early last century, there was widespread support for what could be termed positive eugenics, attempts to improve health through campaigns to prevent communicable diseases and combat alcoholism. But many people built on that to pursue negative eugenics, or the idea one can build a better society by increasing the part of the population considered “superior” and decreasing the population considered genetically “inferior.”

As we move into uncharted territory in medical ethics, what concerns me is how we will respond to the temptations to use science — through genetic manipulation — to create supermen and superwomen.

Faced with the economic rationing of limited health care resources, will we be willing — as others before us were — to listen to those who would abandon people with physical and mental disabilities to build a healthier, more genetically “pure” society? Will we become increasingly hostile to immigrants?

As genetic screening improves, will we find it easier to deny life to those likely to be born with Down syndrome or conditions such as deafness? Will this attitude carry over to people who are considered different, such as those who may be seen to have a genetic predisposition to homosexuality or limited intelligence or poor athletic skills?

In the end, will we devalue the lives of less-than-perfect individuals until we take the next step of choosing to deny them the right to life?

So how do we achieve a moral outcome?

First, we must recognize the competing rights and moral complexities in all of these issues and not fall victim to extremists who see public policy debates as a war where one fights for every inch of ground, and no negotiation is possible. Taking one goal to the extreme is fertile ground for a host of moral compromises on other issues.

Second, we must educate ourselves on the complexities of issues relating to medical ethics, lest technology move ahead of our capacity for moral decision- making.

What the Maltz exhibit helps us understand is that moral outcomes cannot be taken for granted, that even a scientific movement beginning with the best of intentions can be perverted by fear, ignorance, self- interest and demagoguery.

We can create a better world.

We just cannot start by devaluing even a single life.

By David Briggs: http://www.cleveland.com/living/plaindealer/index.ssf?/base/living-0/1190466079177500.xml&coll=2&thispage=2