Logos traditionally indicates calculation, reason and the speech. Heraclites, exploiting the polysemy of the word, returns the term contradictory: on one side, logos explains the world, on the other, it darkens it. In order to learn the logos, we cannot stay behind the level of sense, it is necessary to leave the rational process and the logic of knowledge. Thus, logos shows itself through the shakiness – errors – of the unconscious: hesitations, blunders, stumbles, slip of the tongue. The word in analysis is logos: between structure and what escapes to it.