A negative therapeutic reaction is commonly evoked nowadays when an analysis meets with severe resistances that entail the risk of an interminable analysis. Freud, however, proposed a specific theory of this notion by noting the paradoxical logic at work, namely the appearance of a negative reaction when a symptom has been resolved resulting in increased suffering and a deterioration of the analysand's condition. How are we to understand the fact that some analysands fall into destructive negativity in this way? After following the development of this form of resistance in Freud's thought, while drawing on clinical practice, the author illustrates its deployment in the light of the work of some of his successors.