Introduction

The famous pessimist Schopenhauer, in "The Art of Controversy," turns an experienced eye on "the art of getting the best of it in a dispute. He allows that "unquestionably the safest plan is to be in the right to begin with," but sarcastically adds that "this in itself is not enough in the existing disposition of mankind, and, on the other hand, with the weakness of the human intellect, it is not altogether necessary."

It seems doubtful that the level of public discussion has much improved in our own day. Cogency, to be sure, is admired in the scientific laboratories, just as coherence and sensitivity are encouraged amongst our mathematicians and poets. In the committee rooms of Congress, in the editorials of the chain newspapers, on radio, TV, and billboards -- in all of the noise and distraction in which we live our lives, only a child or a saint could expect truth to prevail simply because it is true. Truth has a chance when Noise and Distraction are on her side; otherwise she may be overcome. And these two can and do daily prevail without her or against her.

The triumph of rhetoric is like the spread of a virus infection. When an epidemic spreads through an area, it is said to prevail there, and local measures may be taken. But to say it prevails does not mean that everyone is infected. Some persons escape infection; others are immune. It is not necessary to labor the analogy in order to show that it would be a good idea if the community could somehow develop a serum against some forms of persuasion.

Few can hope to become immune to all the tricks of persuasion since, like viruses, there are too many of them. People arc daily exposed to appeals to blind faith, self interest, fear, prejudice, fancy. This book cannot discuss persuasion in all its variety and complexity, but it can attempt to describe and illustrate some of the most dangerous strains.

Logic is the defense against trickery. The kinds of argument with which logic deals are the reasonable ones. Mistakes are possible, even frequent, in applying the forms of logical argument, and these mistakes are regarded as fallacies, many of them having been noted as early as Aristotle. We shall wish to guard against them. But the most common fallacies today are of a very different sort. It is a small comfort to know that an argument is entirely logical, that it validly derives its conclusion from its premises, and that all the rules of the syllogism, or whatever, are observed to a nicety, if it turns out that the premises are frauds, snares, delusions. There are brilliant tricks for getting people to accept all sorts of false premises as true (some of these tricks have been spotted since the time of ancient Greece), and these tricks of argument are so prevalent that even when people realize that something is being pulled on them, they tend to let it pass.

Arguments are a highly complicated human activity and cannot be successfully studied in a sort of vacuum, as if the language uttered and answered itself. Like Schopenhauer, we have just had some hard words for the general run of discussion. This discussion at least takes place in a world of activity and interest, is directed toward goals, and, if at all successful, takes shrewd account of human nature. lt is an oversimplification to suggest a clear-cut opposition between argument on one side and persuasion on the other. The most blatant singing commercial usually contains some argument, some alleging of reasons and drawing of conclusions: buy this because it's so good. That the argument is not spelled out, that the audience has to supply the premises, generously allow a connection between them and the evidence cited, and then still accept the conclusion more on faith than reason -- all this does not much matter. Even in logic books the arguments are seldom spelled out, except in the examples. After all, no one is overtaxed by the unstated premise in the argument "This man cannot vote since he is unable to read English." The argument runs:

All voters must be able to read English, (unstated)
This man is unable to read English.
Therefore, this man is not a voter.
(This form of argument is the syllogism, first described by Aristotle; he also noted the fact that in ordinary discussion one of the premises, or even the conclusion, is often assumed rather than expressly stated. Where a premise or the conclusion is unstated he called the argument an enthymeme. The unstated portion always can be supplied so that the enthymeme is expanded into a syllogism as was done here.)

One is not troubled by the ellipsis, that is, by the omission of words expressing an idea that can be taken for granted. Nor does it matter that speakers employ the embellishments, the metaphors, the richness and complexity of the living language. Ordinary speech, arising in a live situation, is not designed to satisfy the formulas of logicians. What does matter is the taking advantage of ellipsis, complexity, and verbal display to deceive and obfuscate. In this book we intend to take a look at some distinguishable varieties of fallacious argument, so that we can recognize them in the speech around us and avoid using them ourselves.

We have chosen to examine chiefly the notorious fallacies. ln our descriptions we try to make it clear what the particular case before us is, and, in the examples, we try to illustrate one particular fallacy at a time, without entirely sterilizing the sample. But fallacies reinforce each other, and in a weak argument there is apt to be more than one thing wrong. In almost all cases the examples are derived from the world we live in. They are representative of actual discussion, so they are often disguised for obvious reasons, though perhaps not out of all recognition, and trimmed down to size.

The word "fallacy" is sometimes used as a synonym for any kind of position that is false or deceptive, and sometimes it is applied in a more narrow sense to a faulty process of reasoning or to tricky or specious persuasions. We will use "fallacy" in the latter sense so that one may say a fallacy occurs where a discussion claims to conform to the rules of sound argument but, in fact, fails to do so.

We classify fallacies under three heads. There is nothing compelling about the arrangement, and many individual fallacies could be placed as well under one heading as another. The divisions are: Part I. Material Fallacies, Part II. Psychological Fallacies, Part III. Logical Fallacies.

This arrangement can be illustrated by a figurative analogy. Suppose we compare argument to a manufacturing process which uses a machine, an operator, and raw materials. If the materials are up to standard, the operator efficient, and the machine running smoothly, the finished product will probably pass inspection. However, three kinds of things can go wrong. The materials can be below standard or poorly prepared. The operator can make a mistake -- get sleepy or be distracted and turn the wrong knob. And the machine itself can break down or misfunction. In any of these three cases, the product will probably not pass inspection. If the trouble lies with the material, we call it material; if with the operator, we call it psychological; if with the machine, then logical. The analogy is crude, but it gives an idea of the emphasis in each section. Under material fallacies we take up faulty generalization and other contaminations of the premises. Under the psychological heading we discuss such common fallacies as emotive language. The processes of logic are rather like those of a machine, and the logical fallacies show a clear misfunctioning of forms designed to go smoothly and produce valid arguments.

We have not by any means exhausted all the things that can go wrong in an argument. What we aim to do is to produce a description of the most notorious fallacies, with some additions that today seem to deserve special notice, and to illustrate them fully.