Many definitions of the precautionary principle exist: Precaution may be defined as "caution in advance", "caution practiced in the context of uncertainty", or informed prudence. Two ideas lie at the core of the principle:Andrew Jordan & Timothy O'Riordan. Chapter 3, The precautionary principle: a legal and policy history, in The precautionary principle: protecting public health, the environment and the future of our children. Edited by: Marco Martuzzi and Joel A. Tickner. World Health Organization 2004
