Carl Sagan muses on the current state of scientific thought, which offers him marvelous opportunities to entertain us with his own childhood experiences, the newspaper morgues, UFO stories, and the assorted flotsam and jetsam of pseudoscience. Along the way he debunks alien abduction, faith-healing, and channeling; refutes the arguments that science destroys spirituality, and provides a “baloney detection kit” for thinking through political, social, religious, and other issues.

Few can talk with more personal authority about the range of human beliefs than Michael Shermer. At various times in the past, Shermer has believed in fundamentalist Christianity, alien abductions, Ayn Rand, megavitamin therapy, and deep-tissue massage. Now he believes in skepticism, and his motto is “Cognite tute–think for yourself.” This updated edition of Why People Believe Weird Things covers Holocaust denial and creationism in considerable detail, and has chapters on abductions, Satanism, Afrocentrism, near-death experiences, Randian positivism, and psychics. Shermer has five basic answers to the implied question in his title: for consolation, for immediate gratification, for simplicity, for moral meaning, and because hope springs eternal. He shows the kinds of errors in thinking that lead people to believe weird (that is, unsubstantiated) things, especially the built-in human need to see patterns, even where there is no pattern to be seen. Throughout, Shermer emphasizes that skepticism (in his sense) does not need to be cynicism: “Rationality tied to moral decency is the most powerful joint instrument for good that our planet has ever known.” — Mary Ellen Curtin

Inheriting the mantle of revolutionary biologist from Darwin, Watson, and Crick, Richard Dawkins forced an enormous change in the way we see ourselves and the world with the publication of The Selfish Gene. Suppose, instead of thinking about organisms using genes to reproduce themselves, as we had since Mendel’s work was rediscovered, we turn it around and imagine that “our” genes build and maintain us in order to make more genes. That simple reversal seems to answer many puzzlers which had stumped scientists for years, and we haven’t thought of evolution in the same way since.

Why are there miles and miles of “unused” DNA within each of our bodies? Why should a bee give up its own chance to reproduce to help raise her sisters and brothers? With a prophet’s clarity, Dawkins told us the answers from the perspective of molecules competing for limited space and resources to produce more of their own kind. Drawing fascinating examples from every field of biology, he paved the way for a serious re-evaluation of evolution. He also introduced the concept of self-reproducing ideas, or memes, which (seemingly) use humans exclusively for their propagation. If we are puppets, he says, at least we can try to understand our strings. — Rob Lightner

A series of anecdotes shouldn’t by rights add up to an autobiography, but that’s just one of the many pieces of received wisdom that Nobel Prize-winning physicist Richard Feynman (1918-88) cheerfully ignores in his engagingly eccentric book, a bestseller ever since its initial publication in 1985. Fiercely independent (read the chapter entitled “Judging Books by Their Covers”), intolerant of stupidity even when it comes packaged as high intellectualism (check out “Is Electricity Fire?”), unafraid to offend (see “You Just Ask Them?”), Feynman informs by entertaining. It’s possible to enjoy Surely You’re Joking, Mr. Feynman simply as a bunch of hilarious yarns with the smart-alecky author as know-it-all hero. At some point, however, attentive readers realize that underneath all the merriment simmers a running commentary on what constitutes authentic knowledge: learning by understanding, not by rote; refusal to give up on seemingly insoluble problems; and total disrespect for fancy ideas that have no grounding in the real world. Feynman himself had all these qualities in spades, and they come through with vigor and verve in his no-bull prose. No wonder his students–and readers around the world–adored him. — Wendy Smith

Twenty years after it topped the bestseller charts, Douglas R. Hofstadter’s Gödel, Escher, Bach: An Eternal Golden Braid is still something of a marvel. Besides being a profound and entertaining meditation on human thought and creativity, this book looks at the surprising points of contact between the music of Bach, the artwork of Escher, and the mathematics of Gödel. It also looks at the prospects for computers and artificial intelligence (AI) for mimicking human thought. For the general reader and the computer techie alike, this book still sets a standard for thinking about the future of computers and their relation to the way we think. — Richard Dragan