Four Main Bodies Of Work

Volume III of the After Such Knowledge Trilogy is one of the four futures of the Haertel Scholium whereas the two tetralogies, Cities In Flight and The Seedling Stars, are independent and parallel future history series. Thus, the relationships between James Blish's four major bodies of work can be encapsulated in a single and aesthetically pleasing sentence. There are:

two tetralogies which are also future history series;
three volumes of the trilogy;
four fictional futures referring to Adolph Haertel who also appears in one novel and one short story.

I became fascinated with this emergent structure which, of course, is not what the individual works are about. Each of the stories or novels is of high quality quite independently of its place in this structure.

Book I of A Case Of Conscience is part of a Twayne Triplet and part of A Case Of Conscience which is part of After Such Knowledge and of the Haertel Scholium. Further, A Case Of Conscience is about the planet Lithia which becomes relevant and therefore is mentioned in the culminating installment of the pantropy series collected as The Seedling Stars.