“The present day is always different from the day that has passed. Yet it is impossible to learn from yesterday in any other except by the method of analogy. Engels’s remarkable pamphlet on the peasant wars is wholly constructed on an analogy between the Reformation of the sixteenth century and the revolution of 1848. To hammer out the concept of the dictatorship of the proletariat Marx heated his iron in the fires of 1793. In 1903 Lenin defined the revolutionary social democrat as a Jacobin, tied up with the mass labor movement. At this time I raised against Lenin academic objections to the effect that Jacobinism and scientific socialism rest on different classes and employ different methods. In itself this was of course correct. But Lenin did not all ‘identify’ the Parisian plebeians with the modern proletariat or Rousseau’s theory with the theory of Marx. He bracketed together only the common traits of the two revolutions: the most oppressed popular masses who have nothing to lose but their chains; the most revolutionary organizations, which lean upon them and which in the struggle against the forces of the old society institute the revolutionary dictatorship. Was this analogy consistent? Completely so. It proved very fruitful historically” [Leon Trotsky, ‘A letter to the Italian Left Communists. Followers of Comrade Amadeo Bordiga’] [(in) Leon Trotsky, ‘Writings of Leon Trotsky [1929]’, 2013] [Lenin-Bibliographical-Materials]  [LBM*]