In a discussion people react more fully to the subject material confronting them because they have to think and formulate views about it, then state those views and then listen to the views of others. Class members are led to see that they have overlooked many aspects of the subject, that everyone has blind spots and that in order to arrive at a mature judgement they have to take in account many shades of opinion and meaning. They should also scrutinize the facts and reasoning of the teacher, who in the discussion situations is taken off his pedestal and drawn into a more equal relationship with students, at least in terms of the subject material. This more intensive contact with the subject in a permissive situation tends to produce more durable learning.