I have spoken of feeling that an argument is fallacious, and of being unable to point out just where it is so. To cease reading for a while, and to endeavor to make these inarticulate objections articulate, is excellent practice for training analytic powers and developing clearness of thought.
Another way of reading a book is what I may call the anticipating method. Whenever a writer has started to explain something, or whenever you see that he is about to, stop reading and try to think out the explanation for yourself. Sometimes such thinking will anticipate only a paragraph, at other times an entire chapter. School and college text-books, and in fact formal text-books generally, often contain lists of questions at the end of the chapters. Where you find these, read them before you read the chapter, and where possible try to answer them by your own thinking. This practice will make you understand an explanation much more easily. If your thinking agrees with the author’s explanation it will give you self-confidence. It will make you realize whether or not you understand an explanation. If you were not able to think the thing out for yourself you will appreciate the author’s explanation. If your thinking disagrees with that of the author you will have an opportunity to correct him—or be corrected. In either case your opinion will rest on firmer grounds. Not least of all you will be getting practice in self-thinking.
After reading and criticising a book, it is a good practice to study one taking a different viewpoint, or written even in direct opposition. You will doubtless find that it points out many fallacies and controverts many statements in the first book, which you allowed to pass unchallenged. Ask yourself what the trouble was. Was your attitude too receptive? Did you swallow words without substituting clear mental images? Did you fail to trace out the consequences of a statement? All these questions will help you do better the next time.
Because of your ignorance of the facts, your failure to refute a conclusion will sometimes not be your fault. But even here, though you cannot contradict an author’s statement of facts, you can criticise conclusions drawn from those facts.
Take an instance. In making an inquiry into the causes of fatigue, Professor Mosso of Turin selected two dogs as nearly alike as possible. One he kept tied, and the other he exercised until it was thoroughly tired. He then transfused blood of the tired dog into the veins of the rested one, and produced in the latter every sign of fatigue. From this he concluded that fatigue was due to certain poisons in the blood.
Now we cannot contradict the fact of this experiment: that the rested animal was made to look tired. But we can question the inference drawn. The truth of the conclusion aside, was the evidence sufficient to establish it? Might not, for instance, similar results have been produced upon the rested dog if blood of another rested dog had been transfused into it? Had Mosso made such an experiment? Other objections should easily occur to one.
Questions which admit of treatment by studying both sides are too numerous to mention. The literature of philosophy furnishes particularly good material. Examples which at present occur to me are Sir William Hamilton’s philosophy versus Mill’s Examination of Sir William Hamilton’s Philosophy, and Herbert Spencer’s First Principles versus William James’ essay, Herbert Spencer’s Autobiography and Henri Bergson’s criticism of Spencer in his Creative Evolution.
Uncritical students of the history of philosophy often find themselves agreeing with each thinker in turn, no matter how much he contradicts previous thinkers, and end by acquiescing in the last system they read about. I remember a philosophy class which completed its studies with Pragmatism. Of course it was merely a coincidence, but at the end of the course fully nine-tenths of the students declared themselves Pragmatists!
It is almost needless to remark that an author who pretends to point out fallacies in another is not necessarily right. There are men who pride themselves on “reading both sides of a subject”; but unless they have been critical, their knowledge is not half as clear or as likely to be true as that of a man who has read only one side, but who has read it critically.