Philippe Kourilsky is a professor at the Collège de France and a member of the French Academy of Sciences. He was formerly director general of the Institut Pasteur. He is the author of Les Artisans de l’hérédité, La Science en partage, Le Principe de précaution and, more recently, Le Temps de l’altruisme, which were all published by Editions Odile Jacob.

‘Our immune system was first studied because of the role it plays in the battle against infectious agents. It was later found to have other functions and particularly that it plays a part in regulating certain internal disorders, including some cancers. It can also help repair damaged tissue.
‘However, my subject here reaches far beyond the immune system: it aims to provide a comprehensive view of the biological mechanisms that defend the organism against life’s hazards, whether of external (infectious agents) or internal origin (operational errors). The significance of such defence mechanisms has been largely underestimated — yet they constitute the hidden face of life, of survival, and are indispensable to the maintenance of life,’ writes Philippe Kourilsky.

How do we resist most infectious agents? How do we overcome some cancers? We cannot answer these questions unless we explore the complexity of life. Living means surviving, Kourilsky reminds us, as he guides us in a fascinating journey to some unexpected biological continents, which only the latest findings allow us to understand.

• A detailed, overall presentation of the defence mechanisms that the human body activates in order to react to the hazards that overwhelm it (allergies, infectious diseases, cancers).
• The foundations of the biology of tomorrow, grounded on our present notions of hazard, complexity and robustness, and based on the central concepts of modularity and networks.