Abstract : This Note is answering an old questioning about the Fényes-Nelson stochastic mechanics. Feynman's interpretation of the Heisenberg uncertainty principle allows to deduce the Brownian fluctuations, which are associated to this mechanics, from an infinitesimal time-discretisation stemming from non-standard analysis. It is therefore no more necessary to combine those fluctuations with a background field, which has never been well understood. Let us add that an extended english abstract is giving most of the details.
