Aggression refers to open, harmful social conduct intended to cause injury or discomfort, including both direct physical acts and indirect relational harm. It stems from a variety of causes, such as frustration or a sense of being disrespected, and is categorized as either reactive or purposeful. Scholars have long debated its significance: Benjamin R. Tucker viewed it as a source of suffering contrary to progress, while W.H.R.
Rivers associated it with anger as a fundamental reaction to threat. Joseph Conrad emphasized its role in generating shared fear and violence, and G. E. Partridge analyzed its manifestations within and outside of social groups. These viewpoints highlight aggression’s dual nature—as both an evolutionary strategy for establishing dominance and a driver of conflict, illustrating its intricate relationship with human and societal evolution.