Without immune systems multicellular life; including people, animals, and plants; would not exist on any large scale. All would be a tempting feast for bacteria and would rot in hours. Without artificial immune systems multi-person civilizations, for example the current 6.5 billion people on earth, would not exist either. Many would die of plague. But we do have such systems. Epidemiology, public health, and medicine fight a continuing battle, largely successful to date. Their successes are legendary. Smallpox is extinct, polio is almost gone, cholera (thanks to John Snow) is a minor problem most places.

We are adept with our ancient enemies, bacteria and viruses. (We are adept, but we should not be complacent. New disease can emerge. And bioterrorists might assist the process.) But today there are new threats: grey goo, black hole production at colliders, runaway global warming, and more. Our artificial immune system needs to learn about them, and learn to balance the risks and the benefits. We need the same type of workers and intellectuals who created epidemiology, public health, and medicine to extend our thought structure to include the new problems.

It is not easy. I used to wonder about the science of John Snow. He did study after study, map after map, to prove that cholera is caused by bad water. I would have thought that he had established this conclusively after the first few studies. Now I get the point. Snow had proved it to himself, but he needed to prove it to others, others who did not want to hear. We have the same problem.

In 1998 Smith Dharmasaroja, a Thai meteorologist, predicted that an earthquake and tsunami "is going to occur for sure." He advocated warning systems, but was not taken seriously. The warning systems he advocated could have saved thousands of lives in the tsunami of December 2004. We need to do better than that.