In 1975, amidst one of the most politically charged phases of his life and work, Louis Althusser decided to write a kind of textbook that would make philosophy accessible to laypeople: "Introduction to Philosophy for Non-Philosophers" is the compelling result. This volume is by no means a simple popular science introductory work - Louis Althusser presents here the essence of his fundamental theses regarding the themes of ideology, science, and religion, as well as the concept of practice, which is central to his thinking and is given a distinct profile here like nowhere else. This book represents a moment of synthesis in Althusser's work, a sparkling snapshot of one of the most influential philosophies of the late 20th century, a crystal-clear introduction to its main categories - and at the same time, a manifesto for thought.