Any powerful technology can be abused.

Scientists study physical things, then describe them; engineers describe physical things, then build them.

On the molecular scale, you find it's reasonable to have a machine that does a million steps per second, a mechanical system that works at computer speeds.

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.

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.

Protein engineering is a technology of molecular machines - of molecular machines that are part of replicators - and so it comes from an area that already raises some of the issues that nanotechnology will raise.

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.