Over the past few decades we have learned a great deal about the behavior of such materials as liquid crystals emulsions and colloids polymers and complex molecules. These materials called soft matter ( matière fragile in French) have neither the rigid structure and crystalline symmetry of a solid nor the uniformity and disorder of a fluid or a gas. They have unusual and fascinating properties: some change their viscosity at our beck and call; others form layers of two-dimensional liquids; some are polarized their molecules all oriented in the same direction and turning in unison at our command; others make up the foams bubbles waxes gums and many other items we take for granted every day. De Gennes one of the world s leading experts on these strange forms of matter here addresses topics ranging from soft-matter physics - the formation of rubber the nature and uses of gum arabic the wetting and de-wetting of surfaces and the mysterious properties of bubbles and foams - to the activities of science: the role of individual or team work the relation of discovery to correction and the interplay of conscience and knowledge. In the best tradition of science writing this book teaches us about both our world and ourselves.