Thirty-eight dishonest tricks which are commonly used in argument,
with the methods of overcoming them.
[ Taken from Straight and Crooked Thinking by Robert H. Thouless, Pan Books, ISBN 0 330 24127 3, copyright 1930, 1953 and 1974. Heartily recommended. ]
In most textbooks of logic there is to be found a list of
fallacies, classified in accordance with
the logical principles they violate. Such collections are interesting and important, and it is to be hoped that
any readers who wish to go more deeply into the principles of logical thought will turn to these works. The present
list is, however, something quite different. Its aim is practical and not theoretical. It is intended to be a list
which can be conveniently used for detecting dishonest modes of thought which we shall actually meet in arguments
and speeches. Sometimes more than one of the tricks mentioned would be classified by the logician under one heading,
some he would omit altogether, while others that he would put in are not to be found here. Practical convenience
and practical importance are the criteria I have used in this list. If we have a plague of flies in the house
we buy fly-papers and not a treatise on the zoölogical classification of Musca domestica. This implies no sort
of disrespect for zoölogists; or for the value of their work as a first step in the effective control of flies.
The present book bears to the treatises of logicians the relationship of fly-paper to zoölogical classifications.
Other books have been concerned with the appraisal of the whole of an argumentative passage without such analysis into sound and unsound parts as I have attempted. Undoubtedly it is also important to be able to say of an argued case whether it has or has not been established by the arguments brought forward. Mere detection of crooked elements in the argument is not sufficient to settle this question since a good argumentative case may be disfigured by crooked arguments. The study of crooked thinking is, however, an essential preliminary to this problem of judging the soundness of an argued case. It is only when we have cleared away the emotional thinking, the selected instances, the inappropriate analogies, etc, that we can see clearly the underlying case and make a sound judgement as to whether it is right or wrong.
The thirty-eight dishonest tricks of argument described in the present book are the following:
Dealt with by translating the statement into words emotionally neutral.
allis implied but
someis true (pp 27–38)
Dealt with by putting the word
all into the statement and showing that it is then false.
Dealt with dishonestly by selecting instances opposing your opponent's contention or honestly by pointing out the true form of the proof (as a statistical problem in association) and either supplying the required numerical facts or pointing out that your opponent has not got them.
Dealt with by stating again the more moderate position which is being defended.
Dealt with by analysis of the formula and demonstration of its unsoundness.
Dealt with by refusing to be diverted from the original question, but stating again the real question at issue.
Dealt with by asking that the connection between the proposition and the alleged proof may be explained, even though the request for explanation may be attributed to ignorance or lack of logical insight on the part of the person making it.
Dealt with by pointing out that this is a reason for making efforts to abolish Y, but no reason for not also making efforts to get rid of X.
Dealt with by denying the usefulness of the principle as a method of discovering the truth. In practice, this can most easily be done by showing that our own view also can be represented as a mean between two extremes.
Dealt with by refusing to discuss the logic of the argument but pointing out the defects of its presentations of alleged fact.
Since the unsoundness of such arguments can be easily seen when the form of the argument is clearly displayed, an opponent who does this can be dealt with by making such a simple statement of his argument that its unsoundness is apparent. For one's own satisfaction when reading an argument of doubtful soundness, it will often be found useful to make a diagram.
Both 12 and 13 can be dealt with in the same way as 11; by restating your opponent's argument in such a simple way that the nature of the device used must be clear to anyone.
This is really an incompetent rather than a dishonest way of arguing. The remedy is to point out how much of the question at issue is a difference in the use of words and how much (if at all) it is a difference as to fact or values.
Dealt with by pointing out that the statement is necessarily true from its verbal form.
Rebutted by pointing out that what is cannot be inferred from what ought to be or from what the speaker feels must be.
Dealt with by getting the term defined or by substituting an equivalent form of words at one of the points where the term in question is used and seeing whether the use of this form of words will make true the other statements in which this term is used.
Dealt with by refusing to accept either alternative, but pointing to the fact of the continuity which the person
using the argument has ignored. Since this is likely to appear over-subtle to an opponent using the argument,
it may be strengthened by pointing out that the argument is the same as saying,
Is this paper black or
white? when it is, in fact, a shade of grey.
argument of the beard) (pp 105–108)
Dealt with by pointing out that the difference is nevertheless real. This again may be made stronger by pointing
out that application of the same method of argument would deny the difference between
white or between
If an opponent uses definitions to produce clear-cut conceptions for facts which are not clear-cut, it is necessary to point out to him how much more complicated facts are in reality than in his thought. If he tries to drive you to define for the same purpose, the remedy is to refuse formal definition but to adopt some other method for making your meaning clear.
The best safeguard against all three of these tricks of suggestion is a theoretical knowledge of suggestion, so that their use may be detected. All three devices lose much of their effect if the audience see how the effect is being obtained, so merely pointing out the fact that the speaker is trying to create conviction by repeated assertion in a confident manner may be enough to make this device ineffective. Ridicule is often used to undermine the confident manner, or any kind of criticism which makes the speaker begin to grow angry or plaintive.
The obvious remedy for this is, when practical, to expose the falsity of the titles, degrees, etc, that are used. The prestige then collapses.
Best dealt with by asking in a modest manner that the speaker should explain himself more simply.
Dealt with by more than ample explanation.
Dealt with by refusal to make the admissions. The difficulty of this refusal must be overcome by any device reducing one's suggestibility to the questioner.
Dealt with by considering whether the person supposed to have authority had a sound reason for making the assertion which is attributed to him.
Knowledge of this trick and preparedness for it are the best safeguard against its effects.
A habit of questioning what appears obvious is the best safeguard against this trick. A particular device of value against it is to restate a questionable proposition in a new context in which one's thought-habits do not lead to its acceptance.
The best way of dealing with predigested thinking in argument is to point out good-humouredly and with a backing of real evidence that matters are more complicated than your opponent supposes.
There is much to be said on both sides, so no decision can be made either way, or any other formula leading to the attitude of academic detachment (pp 166–167)
Dealt with by pointing out that taking no action has practical consequences no less real than those which result from acting on either of the propositions in dispute, and that this is no more likely than any other to be the right solution of the difficulty.
Dealt with by examining the alleged analogy in detail and pointing out where it breaks down.
The absurdity of a forced analogy can best be exposed by showing how many other analogies supporting different conclusions might have been used.
Dealt with by refusing to get angry however annoying our opponent may be.
Dealt with by applying one's opponent's special arguments to other propositions which he is unwilling to admit.
We can only become immune to the effect of this kind of appeal if we have formed a habit of recognizing our own tendencies to be guided by our prejudices and by our own self-interest, and of distrusting our judgement on questions in which we are practically concerned.
Best dealt with by pointing out that other prejudices may equally well determine the opposite view, and that, in any case, the question of why a person holds an opinion is an entirely different question from that of whether the opinion is or is not true.
A similar list of graphical failures and how to correct them can be found in Howard Wainer: Visual Revelations.