This is discussion archived from a time before the current discussion method was installed.
hga: I dropped the following from Brother–Sister Incest
(To be fair, this issue was raised at the time and Smith went through an elaborate explanation of why it really doesn't count. Sure.)
Since that's not quite
how I read the discussion between Mentor and Kathryn in chapter 9, "An Arisian Education", in Children of the Lens
, although it's not unfair. I'll see if I can come up with a more nuanced version.
Also see Heinlein in Expanded Universe
, the chapter "Larger Than Life", in which he relates near the end that:
Your Obedient Serpent
The Lensmen novel was left unfinished; there was to have been at least a seventh volume. As always, Doc had worked it out in great detail but never (so far as I know) wrote it down ... because it was unpublishable—-then. But he told me the ending....
[...] All I will say is that the ending develops by inescapable logic from the clues in CHILDREN OF THE LENS.
wonders if there's a trope for "It was subtext in more innocent times, but it plain text now."
Chuckg: Mentor's explanation wasn't so much as 'why it didn't count as incest' as it was 'why, in your particular case, incest carries absolutely no genetic risks as it usually does'. Answer: After 2+ million years of selective breeding, there weren't any harmful recessive genes anywhere in their DNA to risk reinforcing.
I don't think I would say that humanity has no weaknesses in the series—their weakness seems pretty firmly established in First Lensman to be corruptibility. When looking for human lensmen, they have to bend over backwards to find incorruptible humans—when Samms visits the other special races, corruptibility isn't an issue, but they have other problems, which aren't such a big deal for humans. When we see human lensmen, they're incorruptible, sure, but the non-human lensmen have overcome their species' problems too.
Thor: About the Incest thing: The Arisians were so concerned about the "Critical Path", and getting a 3rd level ready in time to take out the Eddorians before they figured everything out; that they stopped development on the 2nd level of the other 3 species. One assumes that the anti-cross-breeding inhibitions would have been removed (or the 3rd level Kinnisons could have removed them as well), so within a thousand years just naturally there would be lots of 2nd level humans which would have emerged from the gene pool that the Arisians had already developed. This would also have occurred with the other 3 races. There would be 3rd order types pretty quickly. 10,000 years would have been a short time for the 3rd level Kinnisons to wait for a reasonable population, and they could also accelerate the process themselves.