A Philosophical Challenge

I think that sf by Poul Anderson and related authors is philosophical fiction because it asks: what is the nature of mankind and the universe? Imagine technology either progressing or regressing, then ask how this would affect people and how they would respond to it. Next, imagine people traveling through space, time and other dimensions, then ask what they would find there and how they would respond to that.

I think that by now we have addressed every major issue:

the Platonic theory of knowledge, in "Plato's Cave";
whether human beings have souls in "The Martyr";
how social change should, and should not, be managed, in Mirkheim;
whether Artificial Intelligence is possible - all alternative answers addressed;
whether life is common, rare or unique to Earth - likewise;
whether human existence is worth all the suffering involved, in Genesis;
the war and pacifism issue, in many works;
how society should be organized, in the Psychotechnic History;
the consequences of physical immortality, in at least three works;
etc.

Here is the challenge: if there is an issue that we have not addressed, then please highlight it - and we will probably find a relevant passage in the Anderson canon.