Raymo, science writer (Honey From Stone, 1987, etc.) and novelist (In the Falcon's Claw, 1989), zigzags between beauty and bombast in this collection of 21 rambling essays on ``the soul of science.'' Scientists, as Raymo notes, can be ``grim, white-coated technicians wielding power without responsibility.'' What to do? Raymo suggests we make science more human by returning to the lessons of everyday experience. In one essay, he speculates on what our civilization might be like if Earth, like Venus, were wrapped in clouds. Elsewhere, he tackles a question as old as Adam and Eve- -''Who am I?''--finding clues to an answer in DNA research. Other pieces mull over sea squirts, Halley's comet, Neanderthals, SDI, the dangers and blessings of machinery, why there are two sexes, the pros and cons of vivisection--more or less whatever one might hear discussed in a freewheeling science classroom. The binding glue throughout is the ``mediocrity principle,'' Raymo's belief that we and our planet are so commonplace as to be ``cosmically mediocre,'' an idea that might make many nonscientists blanch. All unravels in the second half, as Raymo fires away at creationism, astrology, the New Age, UFOs, and other ``pseudosciences'' about which he seems to know little, and ends up shooting himself in the foot. Beautifully composed--but done in by dogma.