Yesterday's E-chat with bioethicist George Annas about human enhancement and genetic engineering brought up the so-called precautionary principle, which is a "go slow" approach to dealing with new technologies. For a take on the "go fast" approach, here are bits of an E-mail chat I had with James Hughes, a health policy instructor at Trinity College in Hartford, Conn. Hughes is also executive director of the World Transhumanist Association, which "advocates the ethical use of technology to expand human capacities," according to the group's Web site. In addition, Hughes is author of the book Citizen Cyborg: Why Democratic Societies Must Respond to the Redesigned Human of the Future, which will be published by Basic Books in October.

Next News: What's your perspective on the precautionary principle as applied to genetic engineering and other medical technologies?

I was slowly giving up cigarettes in graduate school. There were many days that began with my morning self optimistically thinking about the fact that I didn't smoke much, that I would still have a low lifetime risk if I quit in my 30s, and that we were on the verge of curing cancer. So I would buy a pack and smoke one or two.

Then in the late afternoon, when my blood sugar got low, or I had been humbled in rounds of manhood-measuring with other would-be intellectual giants, I would look with disgust at the pack, think about the fact that cancer was supposed to have been cured a decade earlier, that my family was riddled with cancer, and how pissed off my wife would be if my baby daughter grew up without me. I'd crumple the pack and throw it away.

A day or two later the cycle would repeat. Sometimes by nine at night, deep into cups with my socialist comrades, I'd have another craving and look for another fix. My 9 AM self was a smoker, my 4 PM self a quitter, and my 9 PM self thought that the world was going to hell in a hand basket, so what difference did it make?

Jon Elster writes about such scenarios-the peculiarity of one part of the self trying to bind the other-as the "Ulysses dilemma." Some of us consider our substance dependencies a peripheral element of who we are. Some could easily lose these weaknesses, neuroses and self-destructive behaviors and feel even more true to who we "really are." Some people think that they aren't themselves until they take their drug of choice, whether it's a smoke, drink, Ritalin or an antipsychotic.

This situation will be exponentially complicated by the radical longevity and nano-neural technologies we will soon enjoy. These technologies will force the existential question of who we think we are inescapably upon us.