We often think of science as continuously advancing. In this collection of essays, five world-renowned writers explore obscure and neglected episodes in the history of science which suggest instead that the process of understanding the significance of scientific discoveries can be erratic, contradictory, even irrational. Jonathan Miller, Oliver Sacks, and Daniel Kevles show how promising new ideas may at first fail to be noticed or accepted, and then, years after they have been dismissed or forgotten, are recognized in a different form as important. R.C. Lewontin and Stephen Jay Gould discuss the ways that words and images used by scientists and popularizers alike, from the murals on the walls of natural history museums to such ubiquitous terms as "adaptation" and "environment," reflect serious and often unacknowledged distortions in the way we conceive of both individual organisms and the natural history of the world. These essays demonstrate that science is, in the words of Oliver Sacks, "a human enterprise through and through, an organic, evolving, human growth, with sudden spurts and arrests, and strange deviations, too. It grows out of its past, but never outgrows it, any more than we outgrow our childhood."