For several years, progressive safety experts and scientists have been developing new and pro-active approaches to capturing and understanding safety in complex systems. It is not so much a question of recording when the system is not functioning but rather of understanding successful operation. This is where Human Factors and Ergonomics (HF/E) needs to question whether they want to design safety or just prevent 'unsafety'. A proactive design of safety in this new perspective goes far beyond prevention and risk mitigation. This white paper proposes basic principles for a better integration of HF/E in system design.