Since 2004, future teachers in French-speaking Belgium have received 20 hours of training about « neutrality ». As this concept can be the subject of multiple interpretations, this article aims to : (1) examine its evolution in school legislation in French-speaking Belgium between 1958 and 2018 and to identify the underlying tensions, (2) situate it, in reference to a more international literature, in relation to different conceptions of « living together » and « neutrality », (3) better understand how the trainers in charge of teaching neutrality to future teachers are situated in relation to these different conceptions and, ultimately, determine to what extent they share a common view or not. The results show a great hybridity of conceptions of both living together and neutrality.