Gate 4 (Youthful Folly) sits in the Ajna. It formulates answers: at this stage they are still concepts, not always tested. The mind looks for a solution as soon as it does not understand, then fills with new questions. Logic here justifies and clarifies more than it proves once and for all.
Questions and answers are meant to move with others, not only to soothe a private mind. Gate 63 (Doubt) turns confusion into legitimate questions that Gate 4 can formulate. Together they form the Channel of Logic (4-63).