In the struggle for the renewal of Marxist thought from a practical perspective, the 1970s saw the sharpening of epistemological interests and many of the concepts that are now foundational for the project of the historically-critical dictionary of Marxism. This struggle took place on the terrain of the classics, whose guidelines the Marxism-Leninism claimed to politically implement. In light of its ideological detachment from reality and practical abandonment in the execution of this claim, it was also about immanent criticism, which should always be understood with a certain irony. Intervention was necessary at the fault lines between the conceptual material from which this imaginary was constructed and its actual basis. Many of the contributions collected here were originally intended for a third volume of plural Marxism, which some rejected as heretical before 1989.