My mother�s mother died of a brain tumor. After her diagnosis, she had what was then referred to as �an operation,� lived a few more years � apparently with indifferent quality of life --and then died. My mother, who was sixteen at the time, either remembered little about the details or didn�t know them.

The doctor who treated her probably didn�t know them either. They couldn�t even see the brain in the 1920�s. If you operated on it, you were flying blind. The impulse to cut out a tumor was a response borne of frustration. Not only couldn�t we alter the brain�s function; we didn�t even know HOW it functioned. So when we cut out a tumor, we changed things by trial and error � perhaps the patient lost speech, or motor function, or sight. Sooner or later, we knew what areas of the brain controlled certain functions, but we still didn�t understand how the brain worked.

Almost ten years ago, my own daughter had a brain �lesion.� She was in law school at the time: she had a small incision cut behind her hairline, the lesion was removed and she returned to school in less than a week. It was called a �procedure.� She�s fine. The doctor who treated her knew just about everything: the type of tumor, its location, that it wasn�t dangerous, and how to remove it safely without changing any brain functions.

At the time my daughter had her procedure, I remember thinking that my grandmother probably had had the same type of lesion as my daughter, but before the advances in neurosurgery.

Now we know even more about the brain, and what we know can make even surgery itself outmoded. We not only can image the brain; we can alter it. We can effectively remove tumors without cutting. We can stimulate certain areas of the brain with magnets to improve the symptoms of Parkinson�s disease; we can surgically treat some mental illnesses. The surgery itself can be performed robotically or laparascopically, dramatical lowering the risk and recovery time.

But to see how we can really alter the brain�s function, let�s go beyond surgery into pharmaceuticals. We have had good pharmaceutical treatments for depression, bi-polar disorder and schizophrenia for a while now.

But we�re going further. We are testing drugs for concentration, sleeplessness, depression, enhancement (or erasure) of memory, and what we euphemistically call �executive function� �the ability to multi-task. College students who grew up on Ritalin when they had attention deficit disorder now use it to enhance concentration and keep them awake. Senior citizens take gingko biloba or anything else they can get their hands on to aid their memories. And many people are given anti-depressants to improve their concentration.

Many mental illnesses are now treatable through pharmaceuticals. However, it�s one thing to treat a mental illness and quite another to enhance the brain�s function the way athletes use steroids to enhance their physical function.

There is a fine line between curing disorders and illnesses, and enhancing quality of life. We crossed it a long time ago, probably with estrogen, or Prozac, or Ritalin. Certainly with Viagra. Not only do we think we must live forever; we now think we must live pain-free forever. And happily,at peak performance, forever.

But that�s what musicians in Harlem used to think when they became addicted to heroin in the �50s and Timothy Leary thought when he began dropping acid in the �60s. It�s what �80s disco dancers thought when they became addicted to cocaine. And it�s what welfare mothers think when they become addicted to crack.

Mind-altering drugs are not new. We have been able to change the function of the brain with opium for centuries.

And what have we learned? That a lot of these drugs have long-term consequences that we can�t foresee, some of them pretty deleterious. More important, there are ethical implications involved with their use. Usually, we blow right by these ethical issues, unless they come into direct conflict with religious views, as cloning has.

But can you envision a day when you will be competing for a job with someone who has a prescription for a memory-enhancing or concentration-enhancing drug? Or with someone who no longer needs to sleep? Can you imagine a day when your employer may demand that everyone take these drugs so productivity can be increased?

This day may come sooner than you think. It�s very hard to resist those legal drugs. To paraphrase the ancient Greek philosopher Socrates, the unenhanced life is not worth living.