This is another one of those books that consistently pops up on "best of" lists, as well as "funniest" lists. Though there are quite a few funny parts, I wouldn't call this a comedy; this book is very dark satire, and Miller clearly takes a dim view of human nature.
It quickly became clear why people have been suggesting this novel to me for years: though it takes place in a post-apocalyptic (post-nuclear) future, humanity has been blasted back to a medieval way of life, and the keepers of knowledge are monks of the Catholic church. Sci fi AND medieval history? This book has me written all over it. My only real complaint is that anyone who doesn't have at least a vague understanding of Latin is going to be pretty easily lost, unless they're very good with context.
In Miller's depressing (and depressingly realistic) future, mutually assured destruction wasn't enough to prevent mankind from nearly obliterating itself. Enraged by the death and destruction wrought by men of science, the survivors ritually murder all people found guilty of possessing knowledge, even literacy. The only hold outs are Catholic monks, who lock away and salvage any scraps of humanity's past that they can find. Centuries pass, then millennia - has humanity learned from its gravest mistake? All I can say is that Miller doesn't have much faith in us, and the weaknesses he skewers are readily recognizable in our society today. So the book is funny, in parts, and absolutely brilliant throughout, but also pretty demoralizing and sad.