Freedom of expression and freedom of thought are accepted as essential values of democracy. Instruments of emancipation inherited from the Enlightenment, they seem self-evident because the link between them is so obvious. Yet our modernity forces us to question ourselves, because the technical means today allow everyone to speak, and often to say anything. Hence our concern: is everything that is freely said really part of the exercise of true thought? However, if we sometimes believe that it is an attack on democracy to only ask such a question - in the name of freedom of expression - it seems to us that it is by refusing to ask it that we do the most harm to democracy - in the name of freedom of thought. For it is by affirming that something is not a problem that we make the bed of "one thought" and weaken the regime of freedom, which is only solid in our true ability to debate. Far from wanting to put an end to it, it is therefore by worrying about the abuses to which it may give rise that we take the best care of democracy.