Is Justice disconnected from the expectations of citizens? Are Justice and the Law too rigid with regard to a person wishing to defend himself? It is interesting to observe the difference of point of view between jurists and people who are not initiated to Law, and to wonder about the reasons of this divergence of vision. This thesis proposes to question the notion of "self-defense of persons", a notion that is often a source of emotion and popular misunderstanding. By questioning this notion, we will address the foundations of this notion as well as the difference in regime between the forces of order and the citizens, while evoking some recent media cases (the case of the Nice jeweler, as well as the Alexandra Lange and Jacqueline Sauvage cases). It will thus be demonstrated that self-defense is a social necessity, essential to society. This book is intended for legal experts as well as for people who have questions about this notion and wish to better understand self-defense.