Historically, the approach to patient safety has been more reactive rather than proactive, involving a response to adverse events and near misses after they occur. This book covers two perspectives of safety: Safety I, a reactive approach that emphasizes reducing adverse outcomes and Safety II, a proactive approach that focuses on ensuring actions go as planned. The author discusses how each approach has been applied in health care and other high-risk industries. A PSNet perspective explored what health care can learn from aviation, another high-risk industry.