À Friedrich Engels, 1er février 1858

Heraclitus, the Dark Philosopher by Lassalle the Luminous One is, au fond, a very silly concoction. Every time Heraclitus uses an image to demonstrate the unity of AFFIRMATION and NEGATION — and this is often — IN STEPS Lassalle and makes the most of the occasion by treating us to some passage from Hegel's Logic which is HARDLY improved in the process; always at great length too, like a schoolboy who must show in his essay that he has thoroughly understood his 'essence' and 'appearance' as well as the 'dialectical process'. Once he has got this into his speculative noddle, one may be sure that the schoolboy will nevertheless be able to carry out the process of ratiocination only in strict accord with the prescribed formula and the formes sacramentales. Just so our Lassalle. The fellow seems to have tried to puzzle out Hegelian logic via Heraclitus, nor ever to have tired of beginning the process all over again.