Hard Fantasy

I stated earlier that there is a clear line between fantasy and sf and quoted Poul Anderson even though he goes on to deny that there is a borderline! But I partly disagree with him. A very occasional story can of course sit right on the borderline but it does not follow from this either that there is no borderline or that the vast majority of works of imaginative fiction are not clearly to one or the other side of it.

Anderson cites "Wireless" by Rudyard Kipling, which I have not read so I am dependent on Anderson's summary. Is a departed spirit supernatural or electromagnetic in nature? If this question is both asked and unequivocally answered, then the answer is either fantasy or sf. However, if the question is asked but not answered, then the story inhabits the borderline. (I met a guy who paid rent to one county and rates to another. One local authority owned the land whereas the other administered it.)

In "Fantasy in the Age of Science" IN Anderson, Fantasy (New York, 1981), Anderson suggests that the age of science requires at least some fantasies that are as rigorous as hard sf, stating their premise (magic works, gods and/or demons exist), then logically deducing unexpected and entertaining but fully consistent conclusions from those premises. Apparently, John W Campbell, having nurtured hard sf in Astounding/Analog, then published what I am calling "hard fantasy" in a newly founded "...companion magazine, Unknown Worlds." (p. 278)

Classic hard fantasies include:

Magic Inc by Robert Heinlein;
Operation Chaos by Poul Anderson;
Operation Luna by Poul Anderson;
Black Easter by James Blish;
The Day After Judgment by James Blish.

These five are all written by hard sf writers. Readers might not notice or care that here is a different genre. The Operation... novels are related to Magic Inc as Anderson's Psychotechnic History is to Heinlein's Future History.

The Operation... diptych and Blish's diptych are each part of a greater body of work.