The tendency to absorb the opinions of others manifests itself to just as great a degree in reading. I have held debating up as an example merely because it brings out more strongly, more strikingly, the effects of such a tendency. But how can it be resisted?

If we have thought out a subject thoroughly, if we have acquired a stock of clear and definite ideas on it, criticism in reading will largely take care of itself. By dint of our own thinking we will know what is relevant and what is not; we shall be able to judge the truth and importance of the various arguments offered. The chances are, however, that we shall not have given much previous thinking to the subject, and that even if we have we shall not have gone as far as the author, who doubtless availed himself of other books. Consequently certain problems which he takes up will not even have occurred to us, and hence will not have received our con­si­der­a­tion.

But where our thinking has not helped us, and even where it has, we should look critically upon every statement of an author, instead of lazily acquiescing in it. The difference between critical and ordinary reading, is that in the former we look for objections, in the latter we wait until they happen to occur to us. Even then we do not hold our ob­jec­tions steadily in mind; we are as likely as not to accept later arguments based upon one we have previously objected to. In order to avoid this perhaps the best we can do when we object to any statement or believe we have found a fallacy, is to make written note of it in the margin. To some extent this will prevent forgetting it. Too few or too many marginal notes are both extremes to be shunned. If we make too many we shall be apt to lose a true sense of pro­portion and fail to distinguish es­sential crit­i­cisms from non­es­sentials. The only way we can keep clear of this extreme is to avoid quibbling and hair-splitting, making only such written criticisms as we feel we could unblushingly defend before the author himself. Often however we may feel that a state­ment is untrue, or that an argument is fal­lac­ious, and yet be unable to point out just where or how it is so. In this case perhaps the best plan would be merely to put a question mark in the margin in order to remind ourselves that the statement has not been fully accepted.

We ought to make sure what we object to because it is a peculiarity of the human mind that it does not require evidence for a statement before accepting it; it generally accepts any statement which has no evidence against it. Unless we reject a statement and know why we have done so, it is liable to insinuate itself in our reasoning, and the longer it remains the more difficult it is to get rid of it. This is why it is so important to avoid as many pitfalls as possible at the beginning of a subject.

The reader may find that even when he reads critically he will accept a certain statement at the time; and then perhaps much later, say a month, an objection to that statement will occur to him, or he will see that it at least ought to be qualified. For an explanation of this we must go back to an analysis of the thinking process. Every idea which enters the mind, either from in­de­pen­dent thinking or from reading, is accepted as true if it is in full conformity with our past experience as we remember it. In all thinking or reading, the new idea arouses associates on its entrance. An hypothesis or principle, for instance, arouses in our minds past experiences of par­tic­u­lar instances. If all these conform it is accepted. But in ordinary uncritical reading or thinking, only a few associates are aroused. In critical reading, we look for as many associates as possible, especially those which do not conform. It is this purpose kept in mind which helps to recall and awaken these associates. No matter how critical our attitude, however, we cannot at any given time recall every relevant associate, though later a “non-conforming” associate is likely to occur to us by pure accident.

While you are criticising a book line by line, and after you have finished reading it, you should note the importance and relevancy of the arguments accepted and rejected. While an author may make a statement with which you disagree, its truth or falsehood may not affect the rest of what he has to say, or it may affect merely a few corollaries drawn from it. In other cases the truth of his entire conclusion may depend upon it. Again, an author may in­con­tro­vert­ibly prove something—which is entirely without bearing on the subject. This means that you should keep the precise question constantly before your mind.

Often you will find an author making a statement which really amounts to nothing more than a mere airing of his prejudices, or at best the bare statement of a conclusion. If he says, “Socialism is the greatest menace of our civilization,” and leaves it go at that, not telling how or why, you should mentally note this as a statement, as a statement merely; you should not allow it to influence your opinion either way. Finally, remember that though you may be able to refute every argument an author brings forward in support of a conclusion, his conclusion may still be correct. It is possible for a man to be right for the wrong reasons.

While I believe all the foregoing sug­ges­tions are judicious and necessary, I am willing to admit that their wisdom may reasonably be doubted. But there is one practice about which there can be no controversy—that of making sure you thoroughly understand every idea of an author. While most people will not verbally contradict this advice, their actual practice may be a continual contradiction of it. They will be in such haste to finish a book that they will not stop to make sure they really understand the more difficult or obscure passages. Just what they hope to gain it is difficult to say. If they think it is wasting time to try to understand every idea, it is surely a greater waste of time to read an idea without understanding it. To be sure, the difficulty of understanding may be the fault of the author. It may be due to his involved and muddled way of expressing himself. It may be the vagueness of the idea itself. But if anything this is all the greater reason why you should attempt to understand it. It is the only way you can find whether or not the author himself really knew what he was talking about. To understand thoroughly the thought of another does not necessarily mean to sympathize with it; it does not mean to ask how that other came by it. It means merely to substitute as far as possible concrete mental images for the words he uses, and analyze those images to discover to what extent they agree with facts.

Better to carry this out, you might follow another practice of immense value. Whenever you are puzzled as to an author’s meaning, or whenever you do not care to accept his solution of a problem but are undecided as to what the solution is, or whenever you want to carry an idea further than he has, or above all, whenever an original and important relevant thought is suggested to you, you should take your eyes from your book—shut it if necessary—and let your thinking flow on; give it fair play, even if it takes an hour before your vein of suggested thought exhausts itself. Of course this practice will prevent you from finishing a book as soon as you otherwise would. And if finishing a book be your aim, I have nothing to say. But if your end is to attain true, sound knowledge, knowledge which you will retain; if your object is to become a thinker, the practice will prove of unspeakable benefit. It will not interfere with con­cen­tration. Remember your object is to con­cen­trate primarily on the subject, not on the book; you intend to become a thinker, not an interpreter or a commentator or a disciple of any author.

And there are two reasons why this thinking should not be put off until after you have finished a book. The first and more important is that after you have finished reading, most of the ideas will have unrecallably dropped out of mind. The second is that when you are undecided about the solution of a problem, you will often find later arguments depending upon that solution. Unless its truth or falsity is decided in your own mind you will not know how to deal with these later arguments.