Mises vs. Marx
Ludwig von Mises attempted to dismiss Marx's class analysis based on the fact that capitalists compete with each other for capital, for workers, and for customers. All that is true. And yet it does not refute Marx. Consider: the football players on the Bengals compete with each other for playing minutes. And yet when they go up against the Rams, they will all unite to help defeat this opponent. People can compete within some class, and yet unite as a class when faced with a challenge from a different class.