Louis Pierre Althusser was a French Marxist philosopher.
He was born in Algeria and studied at the École Normale Supérieure in Paris, where he eventually became Professor of Philosophy.
Althusser was a longtime member—although sometimes a strong critic—of the French Communist Party. His arguments and thesis were set against the threats that he saw attacking the theoretical foundations of Marxism. These included both the influence of empiricism on Marxist theory, and humanist and reformist socialist orientations which manifested as divisions in the European communist parties, as well as the problem of the "cult of personality" and of ideology.
Althusser is commonly referred to as a structural Marxist, although his relationship to other schools of French structuralism is not a simple affiliation and he was critical of many aspects of structuralism.