Asimov used
Foundation's Edge
to bring the Foundation universe into the beginnings of a consistency with the rest of his stories, in particular the robot stories, and he used
The Robots of Dawn
to bring
The Robot Novels
into the same consistency. There are no robots in the Foundation universe at least until
Foundation's Edge.
Asimov had discussed with his paperback editors (and friends), the del Reys, Judy-Lynn and Lester, his plans to bring his novels into a self-consistent body of work, and they thought it was a terrible idea. Asimov was worried that the del Reys might not buy the paperback rights, particularly to the sequel,
Robots and Empire,
but his editor, now Kate Medina, said that was Doubleday's worry. When
The Robots of Dawn
appeared, Brian Stableford called Asimov's attempts to bring his various novels into one consistent future history misguided (as a foolish consistency, that is). I suspect that Asimov would have replied that it was his creation and, like God, he could do what he liked with it. I look upon Asimov's concern with this side issue as a kind of playfulness that I find amusing if not altogether artistically rewarding (not, as Stableford would have it, comforting in its claustrophiliac enclosure). We should be willing to concede to Asimov the same kind of freedom we grant to writers of more traditional narrative.