“When a student is in statu pupillari with respect to any subject whatever, he has to believe that things are settled because the textbooks and his teachers regard them as settled. When he emerges from that state and goes on studying the subject for himself he finds that nothing is settled. The dogmatism which is an invariable mark of immaturity drops away from him. He looks at so-called facts with a new eye. He says to himself: ‘My teacher and textbooks told me that such and such was true; but is it true? What reasons had they for thinking it true, and were these reasons adequate?”