An Unfalsifiable Proposition

Fantasy writers may legitimately assume a hereafter for fictional purposes. Poul Anderson sometimes did. Other writers express their own beliefs about a hereafter through fiction, although such fiction must still be classed as fantasy because the hereafter is not (yet) a publicly accessible realm. Arthur Conan Doyle believed in Spiritualism and also wrote fiction about it he but kept the supernatural out of the Sherlock Holmes series which is the part of his work that Anderson refers to.

Science fiction writers can devise scientific rationales for a hereafter, e.g.:

Midsummer Century by James Blish;
Immortality Inc. by Robert Sheckley.

The personality is neither a cerebral process nor a supernatural entity but a semi-stable electromagnetic field or etc.

There is something logically odd about the proposition that there is a hereafter. On the one hand, if there is a hereafter, then we will know about it. On the other hand, the question of whether there is a hereafter does not fully meet the criteria of an empirical question. Thus, if I predict that there will be a total eclipse of the Sun at noon tomorrow, then my prediction is both testable and falsifiable:

if there is an eclipse at noon, then at 12.01 pm we will know that there was an eclipse;
if there is not an eclipse at noon, then at 12.01 pm we will know that there was not an eclipse.

However, if I predict that, after death, you will enter a hereafter, then, if you enter a hereafter, you will know that you have entered a hereafter whereas, if you do not enter a hereafter, you will not know that you have not entered a hereafter. So is it an empirical question?

I discussed some of the issues here.

The Further Future

Some science fiction novels are set on Earth in the far future without giving many details about what has happened between now and then, e.g.:

The Time Machine by HG Wells (802,701 AD, then the Further Vision);
Midsummer Century by James Blish (about 23,000 years hence);
The Winter Of The World by Poul Anderson (at least 10,000 years hence).

Of particular interest to sf readers is whether there has been any space travel, either interplanetary or interstellar, in that time.

However, a Dirac message transmitted in Midsummer Century is received many millennia earlier in Blish's interstellar novel, The Quincunx Of Time, so we know that there has been space travel in that timeline.

What happened between the 1890's and 802,701? Did anyone (re-)invent Cavorite and leave Earth to contend with Selenites or Martians? Wells mostly wrote one-off works and did not connect them into a series.

Decades ago, the Lancaster sf bookseller, Peter Pinto, told me that he thought that The Winter Of The World was set in Anderson's Technic Civilization timeline. On reflection, he added that it might just be that Anderson had got into writing about futures in a particular way so that there seemed to be a connection. If this novel is set in the Technic timeline, then its events occur long after the Fall of the Terran Empire but while human beings who have never seen Earth are still spreading through the galaxy.

The Winter Of The World is so named because an Ice Age has destroyed our civilisation. Mankind, with new racial distinctions, has thrived in various societies, including an Empire, mines metal from the sites of the former technological civilisation and has just re-invented telegraph.

Since I am currently rereading the novel, I will look out for any clues as to which timeline it belongs in but do not really expect to find any - although apparently Sandra Miesel persuaded Anderson that Planet Of No Return could fit into the Psychotechnic future history so it is always possible to re-assess connections between works.