Humanity is about to "break the carbon barrier," and Alan Goldstein, professor of biomaterials science at Alfred University, is worried. "Earth normal life" has depended on a constrained set of chemical reactions, centered on carbon atoms, for nearly 4 billion years. Now that's going to change: Goldstein foresees that nanotechnology will enable us to use a much vaster array of chemical reactions and allow us to comprehensively integrate living and non-living matter. In fact, he believes that nanotech will erase the distinction between living and non-living matter. So what is nanotechnology anyway? Nanotech is the development of a wide variety of precision manufacturing techniques at the atomic scale. Advanced nanotech will eventually enable the creation of computers and memory storage devices the size of sugar cubes to contain the entire information contents of the Library of Congress. It could allow the creation of space elevators that make possible cheap access to orbit and easier flights to the rest of the solar system. As amazing as these achievements would be, they are still just faster better cheaper ways of doing things that people do now. Even medical devices—nanotech pacemakers and even electronic nanotech pacemakers and even electronic nanotech pacemakers and even electronic hippocampus brain prostheses—will be accepted by most people as just part of the normal march of medical progress. These sorts of nanotech devices and products will be seamlessly and unobtrusively integrated into the macro-sized products of everyday life such as cars, computers, and clothes. Such advances raise few novel ethical concerns. Nevertheless, Goldstein is right. Nanotech integrated into the very cells of our bodies will dramatically lengthen our life spans, give us superhuman mental capacities, and enable to us manipulate literally every aspect of the material world including the material that makes us. Goldstein foresees that nanotech will transform humanity from Homo sapiens into a new species: Homo technicus. "Homo technicus won't see like us, breed like us, feed like us, or need like us," declares Goldstein. Goldstein has put his finger on just what worries people when they first hear of the wondrous possibilities offered by advanced technologies. First, let's stipulate that if any future nanobio products are not safe because, for example, they are toxic or somehow dangerously infectious, then appropriate regulations and limitations must be adopted. Safety, however, is not what causes the greatest unease for some who contemplate nanobio. They fear that nanobio enhancements will dramatically change human nature. After all, visionary nanotechnologists have outlined a future in which vastly increased computational power installed in human brains, or advances such as the complete replacement of the human circulatory system with a sapphire vasculoid containing 500 trillion nanobots, are just the beginning of the radical transformations that are in store for us. Goldstein complains that bioethicists have not done enough hard thinking about the ethical issues raised by the possibility of nanobio enhancements. He calls on us all to do a lot of very very very hard thinking before we go forward with the development of nanobio–before we break the "carbon barrier". Goldstein also wants researchers to begin a "dialogue" with the public about these impending revolutionary changes. But this sober call for harder thinking and more dialogue is a characteristic move in much of what passes for bioethical thinking. Instead of providing final answers, academic and government funded bioethicists artfully protest, "I am just asking some hard questions here. It's my job to ask hard questions." But the implication is that technologists and researchers should stop what they are doing until the bioethicists have come up with the answers to all the hard questions that they are asking. As for public dialogue, this usually means setting up some government committee or other that issues a weighty report suggesting that "we" need to think harder about whatever it believes the issues are. Waiting until the ethicists catch up with scientific and technological progress is a recipe for technological stagnation. Slowing innovation is not cost free. It makes a difference to tens of millions of people whether a cure for cancer or heart disease is found in 2010 or 2020. In general, human ethical advancements and understanding follow—and in fact have to follow—in the wake of scientific and technological progress. Why? Because humanity is just terrible at foresight. The plain fact is that bioethics has advanced by codifying what we have learned from our past ethical blunders rather than by anticipating and preventing immoral acts. Forget trying to anticipate ethical problems. Even the smartest people cannot figure out how scientific and technological advances will play out over the next few decades, much less centuries. In 1960 the optical laser was described as an invention looking for a job. By 2005 ubiquitous lasers routinely cut metal, play CDs, reshape corneas, carry billions of Internet messages, remove tattoos, and guide bombs. However revolutionary nanobiotech turns out to be—and I agree with Goldstein that it will be very revolutionary—the revolution will develop incrementally. Humanity will have lots of opportunities for course corrections as we go along. So rather than try to figure out every consequence of doing something in advance, we generally move ahead and if something does go wrong, we jump back and exclaim, "Oh, let's not do that again." That's why we no longer use X-ray machines to measure shoe sizes or paint radium on watch dials. The very good news is that the history of the last two centuries has shown that technological progress has been far more beneficial than harmful for humanity. I see no reason why nanobiotech will not be another step along that beneficial trend line. As for worries about nanobio's effect on human nature, it's worth remembering that human nature is not some property that inheres in the species in general: Human nature belongs to each individual human being, and each one of us has the right to change our own human nature. This means that we all have the right to choose to use or not use new technologies to help us and our families to flourish. If our descendants don't "breed like us, feed like us, or need like us," then that's because they will decide that they have better alternatives. Finally, as much damage as future nanotech devices might cause, it's nothing compared to the damage that bad policies or overly cautious ethical fatwas can make. Is humanity ready to break the carbon barrier? We're about as ready as we'll ever be.