Fahrenheit 451, by Ray Bradbury
After the Destruction (p 163)

"There was a silly damn bird called the phoenix back before Christ, every few hundred years he built a pyre and burnt himself up. He must have been first cousin to Man. But every time he burnt himself up he sprang out of the ashes, he got himself born all over again. And it looks like we're doing the same thing, over and over, but we've got one damn thing the phoenix never had. We know the damn silly thing we just did. We know all the damn silly things we've done for a thousand years and as long as we know that and always have it around where we can see it, someday we'll stop making the goddamn funeral pyres and jumping in the middle of them. We pick up a few more people that remember every generation."

I have read about the phoenix dozens of times and in dozens of references and this is the first time it struck me that it symbolizes the human race so closely. It seems to obvious now, but I never made the connection. I really like it.