E.C. Tubb 
World of Promise 
The Dumarest Saga Book 23

Ascelius was an academic world, whose primary business was teaching the knowledge of the thousands of worlds, and housing great universities and colleges, populated by students and scholars from all over the galaxy. Such a world was surely the place to learn of the legendary planet called Earth. And Dumarest discovered that there had once indeed been a study-group of Earth lore. But to find the remnants of it was not easy. Not when the dreaded Cyber already had a toe-hold on Ascelius — and genetic engineering of man and monster was the latest fad.But Dumarest was not a quitter. Whatever the tests might demand, he would not give up . . . although it might mean death for others — or even for himself.(First published 1980)