A good, solid collection of novelettes by SF great Damon Knight. They don't write 'em like this any more.The Introduction by Knight is better than most, with interesting and amusing insights into the inspiration for the stories; in many cases, they were at least partially reactions against the SF tropes of the day.- "Rule Golden", the title story, is a well-written morality fable in science fiction form, basically. An alien comes to Earth and causes an irreversible reaction in all mammals, activating a latent psi ability; they and their descendants instantly feel whatever pain or suffering they inflict on others. A Fugitive-like situation results, for a while.There are some fairly massive logic holes in the story. It's pointed out that all predators will become extinct. The utter ecological devastation that would result is massively underplayed. Since it was written in 1954, I suppose that's understandable.It's also noted that death can be caused without suffering; for example, meat animals can be rendered unconscious before being slaughtered. This seems to open the door to a whole generation of "painless" criminality and even war.I needn't mention the whole problem that the existence of masochists brings to the concept, I suppose?It's an idealistic story, and therefore less realistic than I would expect - even for science fiction. But it is well-written.- "Natural State" rather reminds me of the work of Eric Frank Russell, particularly his classic The Great Explosion - with a light touch of Blish's Cities In Space, to boot. It's a frankly humorous piece with philosophical overtones, in which technologically-advanced but stagnant cities exist in a state of permanent opposition to the surrounding "country", which is based on biological science. City people are raised to loathe and despise country-dwellers, who outnumber them enormously. The hero is a spy, or emissary, sent by New York City to create a trade relationship with the countrified "Muckfeet".The story can't help but be a bit dated, of course. It was written in 1953, after all, and we've learned a lot more about the potential of the biological sciences. At the same time, some of Knight's extremely clever ideas about bio-engineered animals seem very unlikely.All in all, a good story, but not one of Knight's best.- In "Double Meaning", an official in an ossified and decaying Earth empire must deal with a group of alien spies disguised as human beings. Complicating the picture is the presence of an expert from an independent former Earth colony; his unorthodox and highly effective methods cause widespread irritation. Meanwhile, the official is also involved in an unpleasant romantic battle, with abusive overtones.For some reason this story reminded me of some of the works of Frank Herbert; there's lots of introspection and analysis of emotion and meaning. The end is a little sudden and slightly jarring. All in all, I didn't particularly care for it.- "The Earth Quarter" is one of the most mature works in the book; that may be because Knight rewrote it in 1961. It's thought-provoking and memorable. It is also, unfortunately, a very depressing story.I've never cared for stories that portrayed the human race as inextricably flawed and corrupt. Even though this is quite well-written, it's simply not my cup of tea. I like stories that offer at least a little hope.- "The Dying Man", the final story, is the shortest one in the book. It's also the real gem of the collection. In a world of immortals, one man discovers that he is doomed to age and die. The result is a powerful and extremely memorable reflection on life, aging, and death. I read this story many years ago, and it stuck in my mind; on re-reading it at a more advanced age, I found it even more moving.Rule Golden and Other Stories is something of a mixed bag; the oldest stories are the weakest and most superficial ones, so the book gives an interesting overview of Knight's maturation as a writer. But even the weaker stories are well done, and the book as a whole is well worth picking up. Of course, it's not in print and is unlikely to ever be published again, I suspect. But if you happen to see it in a used book store somewhere, you could certainly do worse than to pick it up.