Kant's answer to the question what is enlightenment is well known: Enlightenment, he says, is "having the courage to think for yourself". Heine thought the German philosopher was a revolutionary more violent than Robespierre. Yet, Kant also says, "think for yourself, but obey!" In reading Kant, Spinoza, Marx, Adorno&Horkheimer, Arendt and Foucault, among others, we shall search the relation between Enlightenment inheritance and revolutionary thinking.