She asks, if I were to explain the term Cartesian to a group of people who didn’t know the term, how would I do it? I tell her the teacher doesn’t remove the wrong answer; only mentions the existence of a wrong answer. She indicates laughter and says she likes my response, but that’s not the reply she was hoping for. I respond: desensitization/familiarization (sic) is a common training tool. Very effective. But she does not let it rest. What, she asks, does Cartesian mean to me? The concept is simple, I say, one of the basic postulates that creates the basis for geometry.