After reviewing some of the main explanations given to the phenomenon of human aggression, which require an interdisciplinary analysis to be carried out, taking into account its multicausality and multi-mensionality, the second part of this article focuses on studying the phenomenon of school violence. First of all, it comes to a halt in its main manifestations: bullying; the aggression of teachers by their pupils, colleagues and superiors; teachers’ assaults on students and, finally, the coercion of the school institution and the pressure exerted by structural violence on all of them. It then looks at the causes of school violence: personal, family and media, as well as those referring to the entire school institution. Finally, by way of conclusion, it proposes a global, dialectic, systemic and ecological explanation of the phenomenon of school violence, reflecting certain guidelines for its prevention and treatment.