After Drexler published his 1981 nanotech paper in PNAS, and after it received some positive followups in Nature and in Science in 1983, why did Drexler next write a popular book like Engines of Creation (1986) instead of a technical account like Nanosystems (1992)? Ed Regis writes in Nano (p. 118):

The logical next step for Drexler… was to produce a full-blown account of his molecular-engineering scheme, a technical document that fleshed out the whole story in chapter and verse, with all the technical details. That was the obvious thing to do, anyway, if he wanted to convince the greater science and engineering world that molecular engineering was a real prospect and not just his own private fantasy.

… Drexler instead did something else, spending the next four years, essentially, writing a popular account of the subject in his book, Engines of Creation.

For a dyed-in-the-wool engineer such as himself, this was somewhat puzzling. Why go public with a scheme as wild and woolly as this one before the technical details were even passably well worked out? Why paint vivid word pictures of “the coming era of nanotechnology” before even so much as one paltry designer protein had been coaxed, tricked, or forced into existence? Why not nail down an ironclad scientific case for the whole thing first, and only then proceed to advertise its benefits?

Of course, there were answers. For one thing, Drexler was convinced that he’d already done enough in his PNAS piece to motivate a full course of research-and-development work in academia and industry. After all, he’d described what was possible at the molecular level and by what means, and he’d said what some of the benefits were. How could a bunch of forward-looking researchers, seeing all this, not go ahead and actually do it?…

The other reason for writing a popular book on the subject was to raise some of the economic and social issues involved. Scientists and engineers, it was commonly observed, did not have an especially good track record when it came to assessing the wider impact of what they’d wrought in the lab. Their attitude seemed to be: “We invent it, you figure out what to do with it.”

To Drexler, that was the height of social irresponsibility, particularly where nanotechnology was concerned, because its impacts would be so broad and sweeping…

If anything was clear to Eric Drexler, it was that if the human race was to survive the transition to the nanotech era, it would have to do a bit of thinking beforehand. He’d have to write the book on this because, all too obviously, nobody else was about to.

But there was yet a third reason for writing Engines of Creation, a reason that was, for Drexler, probably the strongest one of all. This was to announce to the world at large that the issue of “limits” [from Limits to Growth] had been addressed head-on…