Polymath, John Brunner (1974)
I have another dozen or so Brunner books to read, including Stand on Zanzibar and The Sheep Look Up, and I am starting to really enjoy Brunner’s style.
Polymath is an early Brunner Novel that first appeared in an Ace Double as Castaway’s World. This later revision has a good adventure plot plus heavy Brunner themes. It works well.
He had something like 93 novels before he died. That's quite a body of work. A lot of his novels can be found as vintage books on Ebay.