Psychoanalysis can shed light on the division between truth and falsehood in the social sphere based on what is just within the interpretation during the session. The fake according to Donald Trump and others, the post-truth, the “alternative facts,” all arise from a confusion that is not exactly a lie. A photographic image can be seen in many ways and, while the relativistic discourse reigns, some historians have difficulty distinguishing between fiction and truthfulness. In this new sophist rhetoric, some paranoid-perverse invariants at work in Nazi discourse are showing. Freudian conceptions of denial, psychosis and mass phenomena can be applied to the years 1930-1945, but also to the contemporary conspiracy theories, with one difference: totalitarian logic is now diluted in the crisis of the democratic authority. The truths are partial and can be improved from a secular perspective, while religions have both a dogmatic side and a side open to comment. A balanced optimism characterizes the essential defense of a renewed rationalism.