This conference is based on two observations: firstly, we are living in a world of mobility, which opens up new perspectives but also requires vigilance, and secondly, we are confronted with notions that impose themselves on us. These two postulates put to the test the << critical thinking>> that should characterize the researcher's approach.

Research is confronted with different types of "circulation": circulation of people, ideas, practices and methods. These circulations not only have their advantages, they also entail risks and call for action to reduce the inequalities they reflect. These are challenges that only scientific rigor and the critical thinking of the researcher can help to overcome. This requirement also applies to notions that impose themselves on us, even though they deserve specific attention: such as "community", "values" or "decolonization".

We shall see that, in this systematic reflection on the challenges facing scientific research today, the social sciences occupy a singular place. A discussion with the audience will allow to analyze this fundamentally constructive view.