Student: How could a Censor prevent you from thinking of something before you have started to think about it? Isn't that some kind of paradox? Programmer: No problem. Design each Censor to be a machine that is equipped with enough memory that it can remember the way you were thinking several steps before you made a certain particular kind of mistake. Then later, when that Censor recog- nizes a similar state, it steers you to think in some different way so that you then won't repeat that mistake.