Science is still the great intellectual adventure, but now it is also seen as an instrument of profit, power and privilege. Wrongly used, it might yet make the 21st century our last. To make sense of this we need to let go of old ideas and assumptions. In this No-Nonsense Guide, Jerome Ravetz introduces a new way of thinking about science, moving away from simplistic ideas of perfect certainty and objectivity. We must accept uncertainty and ignorance in the field as well as the need for citizens' participation in the policies involving science. The book gives a fresh look at science's history, with a guide to the key theories, and concludes with a questionnaire that enables anyone engaged in science to locate themselves in the bigger picture.