The abundance of questionable explanations is discussed and hypothetically related to common language, habitual teaching, ordinary popularization, rapid expression and audiences of varying levels. Two types of critical passivity in the face of a questionable text are recalled: 'expert anesthesia', which affects people who are very familiar with the subject and "delayed critique" (which is more frequent). The objective of developing early critique (where appropriate) and avoiding excessive inhibition is then advocated. The conditions that may be necessary for teacher preparation are highlighted: a minimal conceptual framework, and the ability to overcome major psycho-cognitive blockages. It is argued that, while access to a series of examples (as in Appendix J) is useful, it is at least as important to convince people that they have the means to use their critical potential and that they are allowed to do. Critical analysis should be seen as the best way to better understanding and, consequently, to greater intellectual satisfaction. Finally, we reaffirm the importance of developing intellectual life on two levels: conceptual and critical. [For the complete volume, "Developing Critical Thinking in Physics: The Apprenticeship of Critique. Contributions from Science Education Research. Volume 7," see ED615688.]