What does the author advocate in the first sentence? 2. Have you ever asked yourself these questions? 3. Can you give examples of groundless beliefs which rest upon “ mere tradition ” or somebody ’ s “ bare assertion ” ? 4. How can a simple “ suggestion ” become a “ belief ” ? 5. How shall we deal with the beliefs developed in early childhood? 6. What are the main beliefs of Roman Catholic and Presbyterian? 7. What does “ parroting ” mean? 8. How should we treat other people ’ s ideas according to the author? 9. What ’ s the author opinion of newspapers and advertisements? 10. Why do we tend to accept only such new ideas as fit in with the ideas we already hold; and all conflicting ideas seem to us “ obviously ” absurd? 11. What propositions should we treat with caution? 1. In future we are going to follow the practice — until it becomes a habit — of classifying propositions according to their grounds. (Para.1) 2. They rest upon mere tradition, or on sb. ’ s bare assertion unsupported by even a shadow of proof ... (Para. 1) 3. Many of strongest convictions were established then. (Para. 2) 4. But if the staunchest Roman Catholic and the staunchest Presbyterian had been exchanged when infants, and if they had been brought up with home and all other influences reserved, we can have little doubt what the result would have been. (Para. 3) 5. It is consistent with all our knowledge of psychology to conclude that each would have grown up holding exactly the opposite beliefs to those he holds now ... (Para. 3) 6. The same thing is true, of course, of many beliefs other than those of a religious nature. (Para. 3) 7. If we had grown up in a community where polygamy or head-hunting, or infanticide, or gladiatorial fighting, or dueling, was regarded as the normal and natural thing — then we should have grown up to regard it as “ obviously ” natural and perfectly moral and proper. (Para. 3) 8. Of course we do not cease ... to adopt new beliefs on mere suggestions ... to take only the most striking examples, the enormous influence of newspapers and the effectiveness of skilful advertising. (Para. 4) 9. Much of what passes as such is not, strictly, thinking at all. It is the mere “ parroting ” of ideas picked up by chance and adopted as our own without question. Most people, most of the time, are mere parrots. (Para. 4) 10. But as we leave childhood, we tend to accept only such new ideas as fit in with the ideas we already hold; and all conflicting ideas seem to us “ obviously ” absurd. (Para. 4) 11. It may be part of the traditional belief of the people or the race. (Para. 5) 12. But we should fully face the fact that beliefs which are merely inherited from the past must have originated at a time when men knew much less than they know today. So the fact that a belief is “ old ” is no argument in its favor. (Para. 5) 13. When we find ourselves entertaining an opinion about which there is a feeling that even to enquire into it would be absurd, unnecessary, undesirable or wicked — we may know that opinion is a non-rational one. (Para. 7) 14. The age-long struggle of the greatest intellects in the world to shake off that assumption is one of the marvels of history. (Para. 9) 15. Many modern persons find it very difficult to credit the fact that men can ever have supposed otherwise. Yet — they did. (Para. 10) 16. An assumed or dogmatic proposition which had been universally accepted as “ obvious ” ; and which, when challenged, was supported by reference to a dogma of Aristotle. Until Galileo actually demonstrated the contrary, nothing could have seemed more beyond possibility or doubt. (Para. 12)