A presupposition is a basic assumption taken as given and determining the way reality is perceived and interpreted. In the classical formulation of NLP, “presuppositions are useful assumptions that we accept and behave as if they were true.” An unrecognized presupposition is experienced not as an assumption but as an “objective fact” and can therefore become fixed as an imprint of the 2nd level (including at the level of beliefs and identity in the Dilts pyramid).