The Cosmonaut crew sits down to discuss Althusser's Lectures on Spontaneous Philosophy of the Scientists. We historically situate the text and talk about Althusser's conception of science and of philosophy, how they both relate to each other and what happens when one exploits the other and "common sense", in the form of the dominant ideology, creeps in. This is followed by a discussion on actual examples of how philosophy and science interrelate, and what it means to defend a materialist line in philosophy. We discuss philosophical practice in politics and end by providing an extension of Althusser's concept to include Spontaneous Philosophy of the Activist, or how "common sense" creeps in to activism, and we end up reproducing liberal concepts in our organizing.