I should probably start a special tag for all this Heinlein rereading I’m doing (I have another one in progress). These books are so short that they hardly count as one novel between them, never mind each, but I’m counting them as two because I have two physically separate books.
Plus they’re not only not one novel, they’re not even two. They are, in fact, four stories — the longest no more than a novella — loosely connected by the idea that humans don’t use all of their brain power, and we could do incredible things if we did.
Oh, and an early analysis of what it is to be human, and whether human rights should be accorded to uplifted intelligent animals.
All in all, a good enough, if slight, set of stories.