Exactly the sort of science fiction you'd be unlikely to sneak on to a litfic fan's radar, given it has spaceships and ray-guns and planets with silly names, and, if not quite any talking squids in space, then certainly a giant hairy toad of philosophical tendencies*, whose poetry gives the book its title. Which is a shame, because it's a masterclass in telling a story through implication, the unsaid, and plenty of sly wit, in exactly the sort of way literature is alleged to do better than SF. True, in places it's right on the edge of being a fairly broad comedy, especially once the blimpish Admiral Beagle hoves into view – the sort of thing which used to get more critical respect back in the sixties, when this was published. A Kingsley Amis of less conventional attitudes, say, or a less openly outrageous young Roth. One device is purloined from Wodehouse, then given an entertaining twist; another comes from a comedian even more respected, albeit not always for his comedies. There are wonderful little lines on ever page; I was particularly fond of one character's introduction as "a red-headed young fellow in the nether region between boyhood and sobriety". Even John Waters' famous line about never selling out, but only because nobody was buying, is here first, albeit in a less readily quotable form. And at the heart of it all, Anthony Villiers, a Jeeves in Wooster's clothing, gently spreading beneficient chaos wherever he treads without ever letting on the least intent.
*Said alien is also at one point described as a "furry jackanapes", which if I ever had business cards, I would be very tempted to put on them.