International audienceTo argue that formalism is the essence of legal reasoning is to consider that the priority given to formal elements constitutes the specificity of legal reasoning, in other words, what distinguishes it from all others. This thesis is far from self-evident as it has been and continues to be challenged and criticized. However, we would like to show that the criticism is based on a certain ambiguity. Not only can formalism not be reduced to its historical dimension, namely as a particular moment of classical legal thought in the United States or as a « école de l'exégèse » in France, but formalism can not be also disqualified because it would not get to the deep of things. This approach to the problem conceals, in our vie...