Four For The Future, one is an installment of his History of Technic Civilization.
Of James Blish's two contributions, one is loosely connected to his Haertel Scholium.
The second of Brian Aldiss' two contributions (see here) is a sequel to his first, which is unusual or even unique for Aldiss.
Themed anthologies are not my preferred form of sf but this one manages to be of interest in more ways than one. The stories have to be individually good and most of these are.
My reading agenda, which is becoming confused, is:
reread the two Aldiss stories;
continue to read SM Stirling's The Sunrise Lands;
read for the first time Anderson's Murder In Black Letter;
read also for the first time Elliot S. Maggin's prose novel, Superman: Miracle Monday;
reread the Fables graphic novels.
I might get bogged down here.