This book traces the history of ethology - the science that studies animal behavior - from its ancient origins jusu'à today. From Herodotus to EO Wilson, via Darwin and Lorenz, the story is full of anecdotes. They are never free, since they still show the evolution of concepts. After this history, the book develops four themes in order to present the different issues of ethology: 1) The physiological mechanisms underlying behavior - 2) What are the development of behavioral modalities in the life of the animal (ontogeny)? - 3) What are the evolutionary advantages conferred by this behavior? - 4) What is the evolutionary history (phylogeny) of it? The book is perfectly accessible to the uninitiated: I recommend it because it is a useful text, pleasant and genuinely intelligent.