Haertel Timelines

Although James Blish's Haertel Scholium does not comprise a single linear future history series, it could be republished in a boxed-set uniform edition with minimal editing. Such a set should exclude the novel, A Case Of Conscience, because that is Volume III of the After Such Knowledge Trilogy and need not be collected twice, which leaves six volumes:

Two Adolph Haertel Volumes

Welcome To Mars

Galactic Cluster: Revised Edition ("No Jokes on Mars" + the short Haertel trilogy)

These first two volumes cover:

Haertel on Mars

Mars

Haertel

Haertel's successors

Two Jack Loftus Novels

The Star Dwellers

Mission To The Heart Stars (+ "A Dusk of Idols")

Two Thor Wald Volumes

The Quincunx Of Time (+ "A Style in Treason")

Midsummer Century

The second and third pairs cover alternative successors of Haertel.

There are alternative versions of Mars and also of the galactic centre. The Haertel who is directly referenced in Mission To The Heart Stars and the Haertel who is indirectly referenced in "This Earth of Hours" cannot be the same Haertel because these works present mutually incompatible accounts of what is to be found at the galactic centre. Consequently, Haertel exists in different timelines.