Today we have big, crude instruments guided by intelligent surgeons, and we have little, stupid molecules of drugs that get dumped into the body, diffuse around and interfere with things as best they can. At present, medicine is unable to heal anything.

After realizing that we would eventually be able to build molecular machines that could arrange atoms to form virtually any pattern that we wanted, I saw that an awful lot of consequences followed from that.

It's a lot easier to see, at least in some cases, what the long-term limits of the possible will be, because they depend on natural law. But it's much harder to see just what path we will follow in heading toward those limits.

I had been impressed by the fact that biological systems were based on molecular machines and that we were learning to design and build these sorts of things.

Likewise nanotechnology will, once it gets under way, depend on the tools we have then and our ability to use them, and not on the steps that got us there.

The basic parts, the start-up molecules, can be supplied in abundance and don't have to be made by some elaborate process. That immediately makes things simpler.

An international race in the relevant technologies is getting under way at this point, not necessarily with an understanding of where that race leads in the long run, but strongly motivated by the short-term payoffs.