Around page 100, I start skimming and never really found a sturdy spot to pick up on the reading again. At this point, Sagan got into a discussion about global warming and sustainable energy solutions, a discussion now nearly 30 years out of date, followed by a discussion on abortion rights (why?), and a philosophical parsing of the Golden Rule, all of which I skimmed through, reading almost nothing. After that, I opened to a chapter on Gettysburg . . . and took it as my sign to DNF. 

I know Sagan is a masterful astrophysicist, a generally smart individual, and he has many worthy and valid things to share, even posthumously. This book, however, is just not for me. 

I think I will try The Demon-Haunted World for my next dip into Sagan and re-assess.

Though the book is now pretty dated at nearly 20 years old, I still recommend a read. Much, though not all, of the science is still sound and even then, it is a snapshot of where we were in the mid-90s. Nearly all of the philosophy and so, so many of the worldwide challenges are still entirely relevant. Carl remains an inspiration long after his death.

As I always think when I finish one of his books; few who have ever put pen to paper have ever been more wise or knowledgeable than Carl Sagan

I'll always appreciate Sagan's good natured logic. He doesn't beat you over the head with it, but rather takes your hand and walks you down the path.

Many topics discussed in this book sound dated because they are tied to current events at the time of writing. However, the topics are still highly relevant, so don't let the publication year dissuade you. I'll admit the text does get a bit dry at times. I guess being reasonable can't always be exciting.

My favorite chapter was probably the one on game theory. That and when he finally said Billions and Billions for real.

Beware that last step, it's a doozy. The end of the book takes on a much more personal tone, and it's a gut punch even when you know what's coming.

"There are some..who think that the number of (grains of) sand is infinite...There are some who, without regarding it as infinite, yet think no number has been named which is great enough...But I will try to show you (numbers that) exceed not only the number of the mass of sand equal of the Earth filled up..but also that of a mass equal in magnitude to the Universe." -Archimedes (CA. 287-212 B.C.) The Sand-Reckoner
medium-paced

Brilliant in the way Sagan so often was, this collection is also even more personal and shows even more insight into the person he was than the other things I have read. One of the pieces that stands out in my mind, perhaps because it was a topical departure than his normal material, is a piece he and his wife wrote regarding abortion and at what point, scientifically, it could be said life begins. I do not agree with everything in the article, but the way in which is was written is something I very much respect. While there was definitely a point they had to make, I do not feel that anything was done to push science to fit it. With that explosive topic, that can't be said of most other work of the kind.
challenging informative inspiring slow-paced

Billions and Billions is a collection of essays and other short writings on various topics by Dr. Sagan. This was his last book, published posthumously. Topics range from science to the environment to technology to philosophical and moral questions related to humans past, present, and future existence. This book is not a deep dive into any of these subjects, but in true Sagan form, is infused through and through with his vast knowledge and profound wisdom. When we lost Dr. Sagan in 1996, the world lost one of the greatest minds and hearts of the 20th century. The chasm left behind is vast, and so needs to be filled. This is a great collection, and perhaps a great introduction to Dr. Sagan.

• The world is so exquisite, with so much love and moral depth, that there is no reason to deceive ourselves with pretty stories for which there's little good evidence. Far better, it seems to me, in our vulnerability, is to look Death in the eye and to be grateful every day for the brief but magnificent opportunity that life provides. - Carl Sagan (Billions and Billions, pg 258)