This book fills a gap in the literature on the Precautionary Principle by placing the principle within the wider context of precautionary reasoning and uses philosophical arguments and case studies to demonstrate when it does—and does not—apply. The book invites the reader to take a step back from the controversy surrounding the Precautionary Principle and consider the overarching rationales for responding to threats to the environment or public health. It provides practical guidance and probing insight for the intended audience, including scholars, students, journalists, and policymakers.