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.

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.

In a sense, artificial intelligence will be the ultimate tool because it will help us build all possible tools.

I've encountered a lot of people who sound like critics but very few who have substantive criticisms. There is a lot of skepticism, but it seems to be more a matter of inertia than it is of people having some real reason for thinking something else.

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.

If you take all the factories in the world today, they could make all the parts necessary to build more factories like themselves. So, in a sense, we have a self-replicating industrial system today, but it would take a tremendous effort to copy what we already have.

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.