METAPHILOSOPHY Vol. 19 Nos. 3 & 4 JulylOctober 1988 0026-1065 $2.00

WHEN IS A FALLACY NOT A FALLACY?

JOEL MARKS

The Problem

I would like to discuss a theoretical problem about the notion of “fallacy” which arises in the context of informal reasoning. Let us consider a simple example of an informally invalid argument:’

The prisoner confessed to the crime

The prisoner is guilty of the crime

The truth of the premiss does not establish the truth of the conclusion because many factors other than responsibility for a crime can influence a person to proclaim responsibility; for example, threats, torture, plea bargaining. Indeed, even if a person who makes a confession believes the confession, the confession may be false; the person may have been brainwashed or may simply be mistaken.

The first logical point I wish to make is that this argument could be enthymematic; that is, it may be understood to contain a suppressed premiss. In this case the most likely candidate for suppressed premiss would be, “If a person confesses to a crime:, then that person is guilty of that crime.”

This does not “save” the argument, of course, because all of the criticism adduced above applies to this suppressed premiss just as surely as it applies to the argument as a whole. But it does put the argument in a peculiar logical light. For if the argument is analyzed as containing these two premisses, it turns out to be valid.

Of course the argument is still unsound, for it contains a false premiss. But what has become of the sense of fallaciousness that attended our first response to the argument? That is the issue I especially mean to address.2

Let me point out at once that the problem is not peculiar to the example I have chosen. I maintain that this is true for allof the so-called

’ The notion, “informally invalid”, will be explicated as this essay proceeds. It is interesting to observe that the present problem is the mirror image of one that

arises with respect to induction. From the standpoint of deduction, every inductive argument is invalid; this is because the conclusion never follows from the premisses with necessity. And yet there are many who would preserve a notion of iinductive validity, which obtains whenever the premisses lend a certain degree of probability to the conclusion. In the informal, as opposed to inductive, case, the situation is reversed. On formal grounds the argument is valid. But informally it is fallacious. What are we to make of this? (In the sequel I shall omit further discussion of induction although its relationship to informal logic needs to be explored.)

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informal fallacies, whose litany graces every text on informal logic3 S O , for example, the argument f rom authority invariably makes implicit reference to some such premiss as, “If a asserts that p , then p is true”. Indeed, this may be precisely why these fallacies are called “informal” (the term, or category, is itself in dire need of analysis), for what they are not is formally fallacious.

Three Responses Let us consider three possible responses to the situation I have highlighted. I will call the first the What You See Is What You Get Response (the “What Response” for short). This is to hold that these arguments do not contain an implicit premiss; thus, they are simply out- and-out fallacious.

Second would be the Bite the Bullet Response. If all informally fallacious arguments are formally valid, then, dammit, they’re not fallacious after all. They only have the appearance of invalidity. But what they are in fact is unsound. This is because they contain a false premiss, albeit an implicit one.

Finally there is the Have Your Cake and Eat It Too Response (Leu, the argument both has a false premiss and is invalid), according to which there is a genuine species of informal fallacy distinct from formal invalidity. I will defend this position.

First let me deal with the two alternatives. The What Response simply will not do. There is no need to heap scorn upon injury when an informal logical misstep occurs. It is enough to point out that someone has made a false assumption (of which, indeed, the person may be largely unawares). But to insist that the person does not even have this in mind (however unconsciously) is to attribute to that person a phenomenal degree of empty-headedness. Indeed, it would be quite psychologically mysterious how such a person could arrive at the conclusion advanced - which does, after all, bear some connection, however misguided, to the explicit premiss - if there were no mental bridge spanning the gap.

Furthermore, the What Response would have the peculiar conse- quence that an argument such as the following

Sally is my uncle

Sally is malt:

would also be invalid (because the validating premiss is missing). But that is absurd. It would also stretch credibility to maintain the double ’ That is, it is true for all those which are truly fallacies, i . e . , inference-types which

partake of some sort of invalidity. Thus, e .g . , 1 would exclude question begging since a question-begging argument is, on any account, valid.

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standard that in the case of valid informal arguments, the unspoken premiss is “present”.

The Bullet Response is an attractive alternative because it points to the true culprit, namely, a false premiss. It is indeed handy to recognize that all of these arguments contain an implicit premiss, for this enables one to articulate precise criticisms. The criticisms will all have this form: “Your argument presumes that p , but p is false because , . .”

Furthermore, this recognition provides one with a general strategy for dealing with all (so-called) informal fallacies, and it is a strategy which, in my view, clearly improves upon the memorization of a long list of fallacy-types. For one thing, such a list is never complete; my Confession Example, for example, fits none of the standard categories. For another thing, the items on such a list invariably mislead our students into thinking that any appeal to authority, etc., is unjustified, which is simply not true. The false-premiss approach invites thinking about the actual merit of each argument.

However, the Bullet Response will not do as a general characteriza- tion of what is wrong with these arguments since it simply fails to account for why a person who reflects upon one of them has a clear sense that it is invalid. It is completely natural and fitting to say of the conclusion (once one has detected what is wrong with the argument): “But that does not follow”.

Here again, though, we do see the very peculiar pairing of (in)validity with truth value, for it is also natural to say, “The conclusion would only follow were it true that a person who confesses to a crime is always guilty of that crime”. This is why I favor the Cake Response, which acknowledges this peculiar double aspect of informal fallacies.

For all that, the flaw which stands out in one of these arguments is not so much the falsity of a (silent) premiss as the inability of a (given or spoken) premiss to support a conclusion. Granted, this is not due to a missing premiss but only to a silent premiss. But what this silent premiss accomplishes (in one’s “rational phenomenology”, if you will) is precisely to render the inference from spoken premiss to conclusion illegitimate.

Now, what specifically about the premiss illegitimates the inference is its falseness. And this is what is so peculiar about calling this a case of invalidity since the very essence of (in)validity is that it transcends the truth or falsity of the premises of an argument. The only thing which distinguishes the kind of false premiss I have drawn attention to is its tacitness in the argument But why should (or how could) silence shift the category of the flaw?

A Possible Resolution I have no knockdown reply to this query. I will only suggest a tactic which may help to assuage the rational conscience. Suppose we think of

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the silent premiss as a pseudo-premiss. This would take away some of the sting of labeling a false-premiss argument (i.e., an argument whose unsoundness is due solely to a false premiss) an invalid argument. But it would not go so far as the What Response, for something remains to bridge the gap between (“genuine”) premiss and conclusion. In fact, let us give it a name: 66warrant’7.4

What is a warrant? I can’t just say it’s a certain type of premiss, for that would defeat my purpose in introducing the concept. So let us say that it is an assumption. Calling it an assumption suggests two things: (i) that it is unspoken and (ii) why it is unspoken. It is unspoken because it is taken for granted.

The term “warrant” itself also nicely suggests that the function of the assumption is to warrant an inference from the (spoken) premiss to the conclusion. It is precisely the logical missing link in these arguments. And, indeed, a warrant always does validate an argument formally.s However, when the warrant is itself unwarranted, so to speak - i.e., when it is false - i t fails to legitimate the argument informally.

A warrant bears a certain resemblance to a principle of logic. Like a formal rule, i t hovers in the background of a spoken argument. One does not normally draw attention to the fact that one’s argument has the form of, say, modus ponens, for one takes for granted that one’s argument has a valid form; nonetheless, it is this fact which legitimates (or illegitimates, if the form happens to be an invalid one, such as asserting the consequent) the inference formally. Similary , one does not normally draw attention to the warrant of one’s argument, for this too one takes for granted; nonetheless, this is what legitimates (or illegitimates, if it is false) the inference informally.

Furthermore, there are special reasons to deny premiss status in particular to rules of logic, as Lewis Carroll’s tale of the tortoise and Achilles illustrates. Just so, there now appear to be special reasons to deny premiss status to warrants.

Another similarity to a rule of logic is that a warrant is a perfectly general statement. Any warrant is asserted of everything in the universe. For example, the warrant that “If a person confesses to a crime, then that person is guilty of that crime” is properly formulated as the universal claim that “For all x , if x is a person who confesses to a crime, then x is guilty of that crime.” This is as much asserted of a toothpick as it is of a human being behind bars.6

Yet a fourth resemblance between a warrant and a rule of logic is that (due to their generality) the method of analogy can be used to disclose a failure of either. For example, to demonstrate the formal invalidity of

I adopt this term from Stephen Toulmin (cf. Toulmin 1958; Toulmin, Rieke, & Janik 1Y84), who may or may not be talking about the same concept. ’ Or rather it would if it were a genuine premiss! More on this below.

Thus, there is still room in logic for the notion “unspoken premiss” since only an unspoken principle would count as a warrant.

WHEN IS A FALLACY NOT A FALLACY? 31 1

If it will snow today, then it will be cloudy today It will be cloudy today

It will snow today

one need only produce the formally analogous argument

If whales are birds, then whales have lungs Whales have lungs

Whales are birds

without explicit mention of the underlying formal fallacy (namely, asserting the consequent).

Just so, in order to display the informal invalidity of

The prisoner confessed to the crime

The prisoner is guilty of the crime

one need only produce the informally analogous argument

The defendant at the show trial confessed to treason

The defendant at the show trial is guilty of treason

without explicit mention of their shared false warrant (namely, “If a person confesses to a crime, then that person is guilty of that crime”).

What distinguishes a warrant from a rule of logic is that a warrant is substantive. And this, presumably, is what provides its informal content. Thus, one must cleave to the subject matter of an argument whose informal validity is being questioned. Even though the objection to such an argument will be principled, it cannot abstract away from the argument’s content to consider only its formal structure.

Conclusion To sum up, my proposal is that a notion of informal invalidity is defensible. An argument is informally fallacious just in case it contains a false warrant. A warrant is an assumed substantive principle which renders the inference from explicit premiss to conclusion valid on formal grounds.

Unfortunately, this proposal still leaves certain matters unsettled. For one thing, it appears to have an internal inconsistency in that the warrant is treated as not a premzss for the purposes of informal invalidity

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but as a premiss for the purposes of formal validity. Were we to allow an informally invalid argument to be also formally invalid by refusing to accord premiss status to the warrant even in the context of formal analysis, then an informally valid argument would also be formally invalid; this is not an attractive alternative.’

Another problem is the nagging qualm that one is attempting to build a solid edifice upon a very weak foundation, that is to say, an entire domain of logic upon what appears to be the mere accident that, from time to time, one of the premises of an argument is left unspoken. Is it not, after all, merely a matter of style whether a person happens to mention the statement which, when unmentioned, goes by the name of “warrant”? But if it were mentioned, the verdict would be clear in case it were false: The argument is unsound because i t contains a false premiss, period.

Nevertheless, what has motivated my attempt to explicate the concept of a warrant remains the strong sense that a genuine but distinctive invalidity informs the informal fallacies.8

University of New Haven West Haven, CT 06516

References Toulmin, Stephen (1958). The Uses of Argument. Cambridge:

Toulmin, Stephen, Richard Rieke, and Allan Janik (1984). An Cambridge University Press.

Introduction to Reasoning (2nd ed.). N Y : Macmillan.

’ Of course, this is precisely the bone of contention with respect to induction, namely, whether a deductively invalid argument can be valid in any sense. ’ I would like to thank David Scharf and David E. White for helpful discussions of

issues related to this essay, Wayne Davis and Scott Lehmann for thoughtful criticisms which remain largely unmet, and David Hitchcock and others in attendance at Conference ’87 on Critical Thinking, organized by John Hoaglund at Christopher Newport College, for a friendly hearing and an introduction to like-minded views.