International audienceDedekind shares Frege’s aim of substituting logical standards of rigour for intuitive imports from spatio-temporal experience into the deductive presentation of arithmetic. But sharing this aim does not mean having the same fundamental goal nor using or inventing the same tools. I will highlight the basic dissimilarities between Dedekind’s and Frege’s actual ways of doing and thinking. Let us not be misguided by words: a contextual and comparative analysis shows indeed that Dedekind gives to the terms ‘logic’, ‘number’, ‘thought’, ‘pure thought’, ‘laws of thought, ‘concept’, ‘object’, ‘function’ a radically different meaning from that which Frege’s work made familiar to most of us. In the light of his semantic and prac...