Johnson


Making Sense of “Informal Logic”     231 

Making Sense of “Informal Logic”1 

University of Windsor RALPH H. JOHNSON 

Abstract:  This paper is an exercise in 
intellectual history, an attempt to understand 
how a specific term—”informal logic”— 
came to be interpreted in so many different 
ways. I trace the emergence and development 
of “informal logic” to help explain the many 
different meanings, how they emerged and 
how they are related. This paper is also, to 
some degree, an account of a movement that 
developed outside the mainstream of 
philosophy, whose origins lie in a desire to 
make logic useful (echoing Dewey) 

Résumé:  Cet article décrit l’histoire 
intellectuelle du terme « logique non 
formelle » pour essayer de comprendre 
pourquoi ce terme est parvenu à recevoir 
autant d’interprétations différentes. Je 
trace le développement de « logique non 
formelle » pour expliquer ses différentes 
significations, leurs émergences, et les 
relations entre elles. C’est article est 
jusqu’à un certain point un récit d’un 
mouvement qui s’est développé hors du 
courant philosophique principal et à partir 
d’un désire de rendre la logique plus utile 
(pour faire écho à Dewey). 

© Informal Logic Vol. 26, No. 3 (2006): pp. 231-258. 

Keywords:  informal logic, formal logic, argument, inference, fallacy, pragmatic 

1. Introduction 

            . 

Having been co-editor of this journal since its inception in 1979 as the Informal 
Logic Newsletter and then its transition to a journal in 1984, and having spent more 
than 35 years working in this area, I believe that this issue of the journal affords an 
appropriate occasion to offer some reflections, yet again, on the term “informal 
logic.” On a number of occasions, Blair and I have offered our views of what we 
call informal logic (1980, 1983, 1987, 1994, 1996, 2000, and 2002). I have long 
been aware, as have others, of the variety of meanings that have come to be 
associated with the term. For a long time, I found this apparent “anarchy”2 both 
perplexing—no similar problem seemed to occur with the term “formal logic”— 
and upsetting. Recently, I have come to a different take on the situation. It came 
about as I attempted, once again, to sort through the history of the term, and the 
various ways in which it has been interpreted. Instead of searching for the one 
true meaning, I began to look for threads. And I began to ask myself: “How did 
this term come to have these quite different meanings?” More importantly, as you 
will see shortly, I asked: “Why?” 

In this paper, I want to provide my answers to those questions. I begin by 
setting forth a number of these differing conceptions of informal logic—just to 



232     Ralph H. Johnson 

show the range. Then I want to sketch the recent history of the term. I believe I 
have assembled a list that is somewhat representative of how “informal logic” has 
been understood. That treatment, though neither comprehensive nor systematic, 
will provide the platform for my attempt to explain this variety and on that basis 
offer some interesting and helpful insights into informal logic.3 

2. An inventory of differing conceptions of informal logic, arranged 
   chronologically 

Introduction 

Here is a partial, but indicative, list of the range of meaning assigned by various 
writers and thinkers to “informal logic”4: 

the logic of substantive concepts (Ryle, 1953) 
the logic of the natural-language counterparts of the formal devices 
(mentioned by Grice, 1975) 
logic that is neither inductive nor deductive (Carney and Scheer 1964, 
Rescher, 1964) 
the logic of argument and informal fallacies (Johnson and Blair, 1980) 
the theory of reasoning (Finocchiaro, 1984) 
the study of principles of good reasoning (Goldman, 1986) 
logic minus deductive and inductive logic (Copi, 1986) 
the logic of argumentation (Blair and Johnson, 1987) 
the theory of critical thinking (Scriven, 1987) 
pragmatic (Fogelin, 1976; Walton, 1990) 
rhetoric (Toulmin, 1992) 
applied epistemology (Weinstein, 1994) 
the study of warrants (Weinstein, 1994: Hitchcock, 2000; Pinto, 2001) 

This kind of range of meaning is unusual. One does not encounter such wide- 
ranging use in connection with “formal logic,” or “inductive logic”—although 
some similarities exist.5 It indicates that “informal logic” is a “fluid designator.” 
And it may be that this variety has sponsored some confusion. In any event, to 
help understand this wide range of meanings assigned to “informal logic,” it will be 
helpful to proceed chronologically. 

The evolution of the idea of informal logic: a sketch 

In this account, I have confined my attention to the dominant print medium—with 
special reference to the scholarly and academic literature from 1950. I do not here 
consider how informal logic has fared in Cyberspace—a subject for another paper.6 



Making Sense of “Informal Logic”     233 

Nor have I attempted to include in this account such cognate terms as “non- 
formal logic,” “material logic” (which comes out of the Aristotelian/Medieval 
tradition), “informal reasoning,” or “informal argument.” 

This inventory is just that—a sample of places where the term “ informal 
logic” has turned up. I have selected texts in which various authors attempt to 
characterize “informal logic,” with particular attention to authors who have 
associated themselves with the informal logic movement. There are two basic 
strands: the first emerged in Great Britain in the 50s and seems to peter out in the 
70s; the second in North America beginning in the 60s and continuing into the 
present. The two strands appear to be independent. 

Informal logic in Great Britain 

1952: Strawson, Introduction to Logical Theory 

In Chapter 8 of this highly influential work Introduction to Logical Theory (1952), 
Strawson draws a contrast between two kinds of logic: Formal Logic and what he 
calls “the logic of language” (230-232). Strawson never, so far as I can tell, uses 
the term “informal logic,” but the contrast he developed certainly anticipated and 
may well have influenced Ryle. He writes: “Side by side with the study of formal 
logic and overlapping it we have another study: the study of the logical features of 
ordinary speech. The second study can illuminate the first, and can be illuminated 
or obscured by it” (231). In his informative article, Aldrich writes: “The final 
remark of Strawson’s cited essay may be tell-tale: ‘Ordinary language has no 
exact logic.’ Such a comment generally comes out of the old preconception of 
logic—the notion that if it were exact, it would be the formal traditional thing. It is 
this position beyond which progress must be made” (1954:384). Now to Ryle. 

1954: Ryle, Dilemmas 

Perhaps the most salient use of the term “informal logic” in this period is that 
found in Ryle’s Dilemmas (1954) in the Chapter titled “Formal and Informal Logic.” 
According to Ryle, Formal Logic maps the inference powers of topic neutral 
expressions or logical constants on which our arguments pivot, terms like “all,” 
“if, then” and “or.” Philosophy, on the other hand, has to do with the topic or 
subject matter concepts which provide the fat and the lean, but not the joints or the 
tendon. According to Ryle, the philosopher examines such notions as pleasure, 
colours, the future and responsibility, while the formal logician examines such 
notions as all, some, not, if and or”(116). Throughout the chapter, the contrast 
Ryle draws is between the formal logician and the philosopher. Only at the end 
(124) does Ryle shift, saying that the philosopher is perforce doing what might be 
called “Informal Logic.” The suggestion that his problems, his results or his 
procedures should or could be formalized is “as wildly astray, as would be the 
corresponding suggestion about the soldier, the cartographer and the trader” (124). 



234     Ralph H. Johnson 

On p. 129, Ryle says: “What I hope to have done is to have brought out for 
examination some features of what I have dubbed the ‘informal logic’ of our 
ordinary and technical concepts; and shown how questions about this informal 
logic are forced upon us by the …quarrels which break out from time to time 
between one team of ideas and another.” Thus for Ryle informal logic is distinguished 
from formal logic by its focal point: formal logic focuses on the logical constants, 
whereas the other logic focuses on issues that arise in the employment of ordinary 
and technical concepts; hence, its close association with philosophy. It is logic 
because it is focused on the study of implications; it is informal because these 
implications hold, not in virtue of form, but rather of content. For Ryle, logic of 
either sort focuses on the implication relationship. 

1975: Grice, The Logic of Conversation 

In this influential paper, Grice contrasts the formalist and informalist approaches. 
I shall take this contrast as de facto a contrast between formal and informal logic, 
even though Grice never uses the term “informal logic.” 

According to Grice, the formalist is interested in developing as much as possible 
a formal account of language and meaning. For this purpose, the formalist has 
developed certain formal devices (here Grice seems to be thinking mainly of the 
truth-functional connectives plus quantifiers, but there is no reason to limit him to 
these). Formal logicians are concerned to develop “very general patterns of valid 
inference” and want to employ formal devices to that end. They want these formal 
devices because of their power (they grow decision procedures) and generality, 
and also because they are capable of greater rigour and precision—ideals that the 
formalist values. Precisely because the formalist tends to view ordinary language 
as confused, ambiguous and potentially laced with bad metaphysics, the formalist 
is prepared to shift to the study of ideal languages, where by that one would 
understand something like a language sufficient for the doing of science, as Grice 
says on page 150. Formalism is thus presented as part and parcel of a program 
that called for philosophy to eliminate metaphysics and model itself after science. 

The informalist, on the other hand, is presented as resisting the demand for an 
ideal language on the ground that it rests on assumptions that should not be 
conceded. (These assumptions are not identified.) Language, the informalist will 
tell us, serves a variety of purposes besides those of scientific discourse, and the 
informalist holds that we can know what an expression means without knowing 
its analysis (pace G. E. Moore). Moreover, the informalist holds that there are 
many “inferences and arguments” (emphasis mine) expressed in natural language 
and not in terms of these devices that are recognisably valid” (157). (Grice gives 
no examples.) According to Grice, the informalist is motivated by the thought that 
there must be a place for an unsimplified and unsystematic logic of the natural- 
language counterparts of these (formal) devices whose job it would be to develop 
rules to appraise the validity of natural language arguments, not expressible by 



Making Sense of “Informal Logic”     235 

means of the formal devices. That enterprise, I take it, would be what Grice thinks 
of as informal logic. It is the logic of the natural counterparts (whatever this 
means) of the formal devices. 

How are the two logics related? Grice says that this second logic may be aided 
and guided by the simplified logic of the formal devices but it cannot be supplanted 
by it. The two logics not only differ but they sometimes conflict: “Rules that hold 
for a formal device may not hold for the natural counterpart” (158). For Grice, 
then, the informalist is concerned with validity in a way that supplements formal 
logic. But it should also be noted that the contrast developed by Grice is heuristic; 
I do not take him to be endorsing either view.7 

Thus Strawson, Ryle, and Grice all see informal logic as contrasting with formal 
logic, and having its own contribution to make. But each sees that contribution in 
different terms. For Strawson, it is focused on the logical features of ordinary 
speech. For Ryle, it is focussed on the logic of our technical and ordinary concepts; 
and for Grice, it is the logic of the natural language counterparts of the formal 
devices. 

After Grice, so far as I can determine, prominent usage of the term virtually 
disappears in Britain. I shift now to the North American scene, where informal 
logic turns up in a quite different setting—logic textbooks. These uses constitute 
the second strand. 

Informal logic in North America 

There are two phases of development, an initial one that begins in 1964 and may be 
taken as ending in 1980; and a second phase that takes us through the 80s and 90s. 

The First Phase of Development8 

1964: Rescher, Introduction to Logic; Carney & Scheer, Fundamentals of 
Logic 

The first occurrence of the term “informal logic” in a textbook (that I am aware 
of) occurs in 1964. It is one of those quirks of history that we find the same term 
appearing in 1964 in two texts, each independent of the other, and each using the 
term to designate a part of the logic text, but neither of them offers an explanation 
of its meaning. So we must infer that meaning from how they use it. 

Rescher. Introduction to Logic. Part I of Rescher’s text is titled “Informal 
Logic.” (Part II focuses on syllogistic logic, Part III on symbolic logic— 
propositional and quantificational—and Part IV on inductive logic.) In the 
introduction, Rescher characterizes Part I as being about informal language and 
common discourse logic, and it covers these topics: Ch. 1, on logic and discourse; 
Ch. 2, on words, names and terms; Ch. 3, on definition and classification; Ch. 4, 
on evidence, argument and fallacies; Ch. 5, on informal fallacies; and Ch. 6, on 



236     Ralph H. Johnson 

logical exposition. “Informal logic” thus appears to be a term used by Rescher to 
refer to a collection of topics, foremost among which are language and its role in 
logic, plus the informal fallacies. 

Carney and Scheer. Introduction to Logic. Here “Informal Logic” is used, without 
any explanation, as the title of Part One of the textbook, containing the following 
six chapters: Ch. 1, on appraising arguments logically; Ch. 2, covering traditional 
informal fallacies (divided into fallacies of relevance, insufficient evidence, and 
ambiguity); Ch. 3, devoted to definitions; Ch. 4, on uses of language; Ch. 5, about 
analogy; and Ch. 6, about dilemmas and paradoxes. Part 2 of the book is called 
“Formal Logic” and Part 3 is called “The Logical Structure of Science.” Although 
Carney and Scheer do not say what exactly they understand by the term “informal 
logic,” here is how they describe Part I: 

Part I, Informal Logic, contains both new and traditional topics and some 
novel treatment of traditional topics. Informal fallacies, which are useful in 
motivating students in the study of logic, are treated in the traditional manner. 
The standard topics—analogy, dilemmas, uses of language, classifications 
of methods of defining terms and types of definition—are also discussed in 
this part. But two topics are introduced—paradoxes and nonsense—which 
are not found in many introductory logic textbooks. The discussions of 
nonsense and the uses of language are designed to bring to the attention of 
the student some of the immediate connections between logic and language 
and to show the student the significance of logic to philosophy. (vii) 

While Carney and Scheer believe that there are traditional topics for informal logic, 
it is not altogether clear what tradition they have in mind. Their innovations are 
aimed at showing the student the significance of logic for philosophy, rather than 
putting it forth as a tool for the appraisal of reasoning in everyday situations. Based 
on their description and the contents of Part One, Carney and Scheer mean by 
“informal logic,” besides the informal fallacies, “these matters related to logic not 
taken up by formal logic.” This may be the first expression of the idea that informal 
logic attends to those matters left over from, or not attended to, by formal logic: 
such matters as encoding the argument into the canonic notion of formal deductive 
logic, or the role of language, for example. Here we see informal logic assigned the 
role of adjunct to FDL.9 

Rescher’s use of “informal logic” differs slightly from that of Carney and 
Scheer. He seems to take the term to refer to dealing with the informal fallacies and 
matters of language. Such differences in the meaning assigned to “informal logic” 
continue to occur as the term gains currency. 

1976: Munson, The Way of Words: An Informal Logic 

Munson is, to the best of my knowledge, the first textbook author to offer 
what he calls a “rough and ready definition” of “informal logic”: 

Informal logic is the attempt to make explicit the principles or standards that 
are involved in the ordinary everyday activities of establishing and evaluating 



Making Sense of “Informal Logic”     237 

claims and using language effectively in the processes of communication 
and rational persuasion. (3) 

Munson sees informal logic as an inquiry concerned with the principles for the 
appraisal of everyday arguments, thereby giving informal logic a distinct sphere of 
operation—an important development. Its principles emerge from reflection on 
the practice.10 This turns out to be an important, though perhaps insufficiently 
appreciated, insight in helping to understand the development of informal logic. (I 
return to this point later.) 

1977: Johnson and Blair, Logical Self-Defense 

 This text was among the first generation of informal logic texts, yet there is only 
one occurrence of the term “informal logic.” It occurs in the Preface (xii) when 
we refer to the mesmerizing grip of formal deductive logic and say that “one 
consequence has been to relegate informal (or applied) logic—the study of fallacies— 
to a position of minor importance.” At this time we considered informal logic and 
applied logic to be roughly synonymous. Later we would mark a difference between 
them, according to which applied logic is more like applied formal logic (Pospesel, 
1978), and informal logic is related to arguments in natural language. In this text, 
we take informal logic to involve the use of fallacies to critique arguments, but we 
extrapolate from the fallacy approach a theory of evaluation, according to which 
the premises of an argument must satisfy three criteria: they must be relevant to 
the conclusion, sufficient to support it, and acceptable to the audience. This set of 
criteria has proven to be quite influential11 and may be said to be one prominent 
feature of this emerging tradition. 

Our conception here has integrated a number of features that have emerged 
thus far: the focus on teaching a logic that would be useful, the appropriation of 
the fallacies approach (following Kahane), the focus on natural language argument, 
and the distancing from FDL (following Scriven (1976)). 

1978: Fogelin, Understanding Arguments: An Informal Logic 

 Fogelin uses the term “informal logic” as the subtitle of his textbook, Understanding 
Arguments (1978), where he writes: 

For certain purposes arguments are best studied as abstract patterns. . . . The 
task of Logic is to discover the fundamental principles for distinguishing 
good arguments from bad ones. The study of those general principles that 
make certain patterns of argument reasonable (or valid) and other patterns of 
argument unreasonable (invalid) is called formal logic. 

A different but complementary way of viewing an argument is to treat it 
as a particular use of language: arguing is one of the things that we do with 
words. This approach places stress upon arguing as a linguistic activity….It 
raises questions of the following kind: What is the place of argument within 
language as a whole? In a given language, what words or phrases are 



238     Ralph H. Johnson 

characteristic of argument? What task or tasks are arguments supposed to 
perform? When an approach to arguments has this form, the study is called 
informal logic. (v-vi) 

Fogelin goes on to mention the work of Grice (and Austin) as significant, though 
his understanding of informal logic appears quite different than Grice’s. Fogelin 
contrasts informal logic with formal logic which is here taken as “the study of 
those general principles that make certain patterns of argument …valid.” It appears, 
then, that by “informal logic,” Fogelin, focusing on the activity of arguing, 
understands it as the study of the linguistic and pragmatic aspects of argument— 
a view that will resurface—the second phase. 

1978: Blair and Johnson, Proceedings of The First International 
Symposium on Informal Logic (Published in 1980) 

Johnson and Blair first made thematic use of the term “informal logic” in the title 
of the 1978 conference, “First International Symposium on Informal Logic,” which 
we organized at the University of Windsor. We had been using the term “applied 
logic” to designate our enterprise, but the term “informal logic” recommended 
itself to us to designate this new approach to the teaching of logic in virtue of a 
renewed interest in the informal fallacies. Kahane had made informal fallacies the 
focal point of his revolutionary textbook, which we had used in our classes, and 
Woods and Walton had already begun their ambitious research project focussing 
on the informal fallacies.12 We had found ourselves engaged in teaching students 
how to evaluate arguments—a task we associated with logic. Following Kahane, 
we took as our focal point actual arguments about the issues of the day taken from 
current newspapers and magazines, as contrasted with the fabricated arguments 
found in most standard logic texts of that time. See, for example, Copi’s Introduction 
to Logic (1954). The logic we were teaching was not formal logic: we made no 
reference to the logical form of arguments in understanding their structure, and 
we did not make the standard of validity part of our theory of evaluation, using 
instead our version of the fallacy approach (as outlined above). Since the fallacies 
in question were the informal fallacies, the term ‘informal logic’ seemed appropriate 
to us. 

In the Introduction where we made our first attempt to articulate the denotation 
of “informal logic,” we noted the wide range of meanings associated with the 
term: 

The label “informal logic” means different things to different people. To 
many it refers to the lists of informal fallacies and various descriptions and 
classifications of these fallacies… To others it designates the subject matter 
of a certain sort of introductory logic course which employs various nonformal 
techniques to try to teach elementary reasoning skills. To still others it has 
come to mark off a field of logical investigation distinct from formal deductive 
logic. (Blair and Johnson 1980, ix.) 



Making Sense of “Informal Logic”     239 

In our paper, “The Recent Development of Informal Logic” (1980), we avoided 
any direct statement of what informal logic was but noted two tendencies that 
seemed to us to be identified with this development. The first was the turn in the 
direction of actual arguments as contrasted with the artificial types of argument 
often found in formal logic textbooks. The other was the growing disenchantment 
with the capacity of formal logic to provide the standards of good argument. It is 
also evident that (like Munson) we see informal logic as an autonomous area of 
inquiry which we subdivided into (a) the theory of fallacies and (b) the theory of 
argument (1980: 610).13 Also in those same proceedings, a harbinger of future 
issues can be detected: Woods sounded an important skeptical note in his paper 
“What is Informal Logic?” His answer to that question is: “Nothing is.”14 

Summation 

 I conclude my treatment of the first phase of development at this point in time for 
a couple of reasons. The Symposium in 1978 was a coming together of many who 
helped launch the “informal logic movement.” It also witnessed the beginnings of 
a journal—the Informal Logic Newsletter—which in turn figures prominently in 
the second phase. 

In this first phase, the term emerged spontaneously and independently in 
different places. The uses made by Rescher and Carney & Scheer appear 
independent of each other; Munson does not appear to have been influenced by 
either. Our (1977) use was not influenced by our knowledge of prior uses; for we 
had none when we were writing our text. Yet particularly in these last three usages, 
some convergence is discernible: viz., “informal logic” designates a new approach 
to the teaching of logic in which formal logic is de-emphasized. In this phase, it 
should be noted that there is very little theoretical literature to refer to. (See “A 
Bibliography of Recent Work in Informal Logic,” Blair & Johnson (1980: 163- 
172).) 

The Second Phase of Development 

1984: Finocchiaro, Informal Logic and the Theory of Reasoning 

In this important paper, Finocchiaro reflects on the various uses of the term, 
referring to the “identity crisis of wondering what on earth informal logic is supposed 
to be”. He says that he plans to bypass these difficulties by conceiving informal 
logic as the theory of reasoning, by which, he says, “I mean the attempt to formulate, 
to test, to clarify, and to systematize concepts and principles for the interpretation, 
the evaluation and the sound practice of reasoning” (22). This is a much broader 
conception of informal logic than has emerged thus far because Finocchiaro takes 
reasoning rather than argument to be the subject matter. We will see shortly that 
this conception of informal logic influenced Johnson and Blair’s 1987 definition. 



240     Ralph H. Johnson 

1986: Copi, Informal Logic 

After more than 30 years of publishing introductory and symbolic logic texts, and 
symbolic types, Copi decided in 1987 to publish an informal logic text. In the 
Introduction he writes: 

 Although I have been teaching undergraduate courses in logic since 1939, it 
was only about a half a dozen years ago [roughly, 1980] that I first taught a 
course in the subject now known variously as informal logic or critical thinking. 
(vii)15 

In speaking of how his text was composed, Copi says: 
In no way should either informal logic or introduction to logic be viewed as 
the preparation or prerequisite for the other. Hence I have not hesitated to 
incorporate into this informal logic textbook material from the informal part of 

my older Introduction to Logic (viii). 

In fact, the chapters here are as follows: Introduction; Chapter 1—Some Uses of 
Language; Chapter 2—Fallacies; Chapter 3—Definition; Chapter 4—Analogy; 
Chapter 5—Causal Connection; Chapter 6—Science and Hypothesis. These have 
been downloaded from his Introduction to Logic verbatim. Omitted are the chapters 
on Deduction and Probability. Thus, on the basis of the contents of this textbook, 
one might conclude that for Copi informal logic is standard logic minus deductive 
logic and inductive logic/probability theory. This tends to create the impression 
that the way to create an informal logic text is to start with traditional logic, remove 
the deductive and inductive logic sections (what hard-nosed philosophers think of 
the as the real logics) and what you are left with is informal logic.16 Such an 
approach might be called “informal logic by subtraction” but the result is similar to 
what we saw in Carney & Scheer and Rescher; informal logic covers the fallacies 
and elements of discourse analysis. 

1986: Goldman, Epistemology and Cognition 

We look now to a very different kind of source. In this work, Goldman makes a 
brief reference to what he calls “informal logic”: 

It is widely assumed that logic deals with principles of good reasoning. Logic 
is often characterized as the art of reasoning. Unfortunately, such a billing is 
a bit of a sham. It isn’t that logic courses are not useful for good reasoning; 
it’s just that there are no well-established principles of good reasoning (good 
cognitive state transitions), and no satisfactory theory of how good 
reasoning is related to formal logic. In short, there is not a really well- 
established discipline of informal logic. (82) 

By “informal logic,” Goldman understands something quite different from any 
understanding that has turned up thus far. He sees informal logic as developing 
principles of good reasoning (conceived as cognitive state transitions)—a task that 
formal logic is not helpful with.17 It would also clarify the relationship between 
good reasoning and formal logic.18 Here informal logic is conceived of as an adjunct 



Making Sense of “Informal Logic”     241 

to FDL, though differently from the way that Rescher, and Carney & Sheer 
conceived it. 

1987: Johnson and Blair, “The Current State of Informal Logic,” 1987 

In a paper written for the 1988 World Congress of Philosophy (published in Informal 
Logic), Blair and I put forward, for the first time, a definition of informal logic: 
viz., “a branch of logic whose task is to develop non-formal standards, criteria, 
procedures for the analysis, interpretation, evaluation, criticism and construction 
of argumentation in everyday discourse.”19 This definition reflects what had been 
our practice, as is evident in the successive editions of Logical Self-Defense, and 
captures what many others were doing in their informal logic texts. One can 
detect the influence of Finocchiaro (1984) in the reference to “standards, criteria, 
procedures, interpretation evaluation.” Since that time we have repeated the definition 
in (2000, 2002) and in the latter made one modification: we broaden the focus now 
to include the sort of argument that occurs not just in everyday discourse but also 
disciplined inquiry—what Weinstein (1990) calls “stylized discourse.” In (2000, 
119-120), I explain the sense of “form” at work in our conception. 

1987: Govier, Problems in Argument Analysis and Evaluation 

 Govier is one of the philosophers most associated with the development of informal 
logic. In (1985) she authored a well received and widely adopted logic text—A 
Practical Study of Argument. About this volume, she writes: 

My interest in the subject covered in this book dates from 1978, when I came 
across several texts in applied, or informal logic, and was interested both by 
their practicality and by their recommendation for rethinking central 
philosophical traditions regarding logic and argument. I thought at that time 
that very fundamental issues were at stake but that the context of textbooks 
did not provide sufficient opportunities to explore them in depth. This book 
is an attempt to fill that gap. (ix) 

For Govier, informal logic denotes the art of argument evaluation, a task which 
Govier insists is nonformal in character: 

Logic is supposed to be both scientific and practical.... There is a tension in 
these views of logic. We cannot have it both ways—that logic is entirely 
formal and yet applies to real argumentation. Either logic is nonformal or it 
tells us only a small amount of what we need to know and understand and 
evaluate arguments. (203) 

Note that she uses “nonformal” rather than “informal” but her regular reference is 
to the latter, as is the case in the next passage: 

To speak of informal logic is not to contradict one’s self but to acknowledge 
what should be obvious: that the understanding of natural arguments requires 
substantive knowledge and insights not captured in the axiomatized rules of 
formal logic. The informal fallacies, historically a central topic for informal 
logic, involve mistakes in reasoning which are relatively common, but neither 



242     Ralph H. Johnson 

formal nor informally characterizable in any useful way. The fact that an 
account of informal logic makes it out to be just that does not show that it is 
imprecise or lacking in rigor. (204) 

Thus, for Govier, informal logic is the logic that helps evaluate natural-language 
arguments—a process requiring substantive knowledge and insights not provided 
by formal logic. Noteworthy as well is Govier’s connection of informal logic with 
the informal fallacies, and her insistence that the qualities of rigour and precision 
need not be forfeited when one does informal logic. 

1989: Walton, Informal Logic: A Handbook for Critical Argumentation 

This work is important because it was the first monograph dealing with informal 
logic to be published by one of the leading publishing houses—Cambridge University 
Press.20 Walton had already established a reputation as one of the leading theoreticians 
associated with informal logic. His approach here is largely descriptive and 
discursive. Noting the importance of what he calls “logical semantics”, he states 
that “the other eight chapters are mainly about the pragmatics of argumentation” 
(ix), since “applying critical rules of good argument to argumentative discourse in 
controversial issues in natural language is an essentially pragmatic endeavor” (ix). 
Walton is among the first to associate informal logic with pragmatics21 and the first 
to conceive of informal logic as rule-based. Most approaches to informal logic up 
to this point were criteria-based. He writes: “The job requires many of the skills 
associated with the humanities…thus the terms informal logic and critical 
argumentation are well suited to the subject matter of this handbook.” Walton 
states that the “basic requirement of critical argumentation is that any argument 
that a critic attempts to evaluate must be set out as sympathetically appreciated in 
the context of dialogue in which the argument occurs” (ix-x). This is a significant 
shift in how the realm of informal logic is understood. Prior to this, most theorists 
took the focal point to be the argumentation that occurs in a text written for an 
audience.22 Instead Walton here sets the focus in the setting of a dialogue. (One 
senses here the influence of Hamblin, who in Fallacies criticizes formal logic and 
winds up endorsing a formal dialectic (Chapter 8.) ) Walton later refers to this as 
“the dialectical approach” (x), in the question-answer context of an argument and 
concludes: “Thus generally the theory of informal logic must be based on the 
concept of question-reply dialogue as a form of interaction between two 
participants, each representing one side of an argument, on a disputed question” 
(x). Here then informal logic is presented as a pragmatic undertaking23 in the setting 
of a dialogue. 

1989: Perelman, “Formal Logic and Informal Logic” 

I include this entry because of Perelman’s importance in the area of argumentation, 
known for his development of The New Rhetoric (1958/1969). Here is his way of 
contrasting formal and informal logic: 



Making Sense of “Informal Logic”     243 

While formal logic is the logic of demonstration, informal logic is that of 
argumentation. While demonstration is either correct or incorrect and binding 
in the first case or worthless in the second, arguments are more or less 
strong, more or less pertinent, more or less convincing. In argumentation, it 
is not a matter of showing (as it is in demonstration) that an object quality 
(such as truth) moves from the premises toward the conclusion, but rather it 
is a matter of showing that one can convince others of the reasonable and 
acceptable character of a decision, based on what the audience already 
assumes and based on the theses to which it adheres with sufficient intensity. 
Persuasive discourse therefore aims at a transfer of adhesion, of a subjective 
quality which may vary from mind to mind. (11) 

The contrast between the logic of demonstration and the logic of argumentation 
fits well with the emerging view of informal logic as focused on argumentation, 
although his view of argument is somewhat narrower (a reasonable decision), and 
the main criterion for premise-adequacy is acceptance, with which many who 
were doing informal logic would not be happy. 

1990: Walton, “What is Reasoning? What is an Argument?” 

In this paper, Walton presents a slightly different take on informal logic, based on 
the contrasting relationship between formal and informal logic. Walton writes: 

Formal logic has to do with the forms of argument (syntax) and truth values 
semantics)....Informal logic (or more broadly, argumentation, as a field) has to 
do with the uses of argumentation in a context of dialogue, an essentially 
pragmatic undertaking. (418-419) 

Here he invokes the same ideas as in 1989, but discussing the relationship between 
formal and informal logic, Walton writes: 

Hence the strongly opposed current distinction between informal and formal 
logic is really an illusion, to a great extent. It is better to distinguish between 
the syntactic/semantic study of reasoning, on the one hand, and the pragmatic 
study of reasoning in arguments on the other hand. The two studies, if they 
are to be useful to serve the primary goal of logic, should be regarded as 
inherently interdependent, and not opposed, as the current conventional 
wisdom seems to have it. (419) 

When properly understood, these two logics are not in competition but rather are 
complementary. (The claim that they are interdependent needs elaboration.) To 
spell out their complementary nature, Walton relies on the traditional distinction 
between syntax, semantic and pragmatic, assigning to formal logic the syntactical 
and semantical aspects of the study of argumentation, and to informal logic the 
pragmatic aspects. Hitherto there had been an underlying current that saw formal 
logic as antithetical to informal logic (see Scriven, 1980; Johnson and Blair, 1980). 



244     Ralph H. Johnson 

1990: Hansen, An Informal Logic Bibliography 

Hansen’s bibliography (published in Informal Logic) contains over 900 entries 
from journals in which work pertinent to informal logic was being published. The 
index consists of 24 categories under which the entries are distributed: various 
fallacies, argument evaluation, argument interpretation (the principle of charity), 
argumentation theory, arguments—their nature and analysis; bibliographies; critical 
thinking; deduction/induction/conduction; dialogic, fallacy theory, formal and 
informal logic, histories, etc; inference norms; informal logic and critical thinking; 
unexpressed premises (assumptions), pedagogy; relevance; the rhetorical dimension. 
These categories well reflect the sorts of issues and concerns that we have seen 
developing under the rubric of “informal logic.” 

1995: The Oxford Companion to Philosophy, Tully24 

Informal logic examines the nature and function of arguments in natural 
language, stressing the craft rather than the formal theory of reasoning. It 
supplements [emphasis added] the account of simple and compound 
statements offered by formal logic and … widens the scope to include inductive 
as well as deductive patterns of inference. Informal logic’s own account of 
arguments begins with assertion—whose real meaning in natural language 
is largely ignored by formal logic. Because informal logic sees assertion and 
argument as woven into the fabric of discourse, the threads it traces are 
extremely varied: imbedded but possibly incomplete patterns of deductive 
and non-deductive inference, hidden assumptions, conversational 
implications, vagueness, rhetorical techniques of persuasions, and, of course, 
fallacies. Such topics though important for understanding arguments in natural 
language, lead it from the concerns of formal logic. That informal logic lacks 
the precision and elegance of a formal theory is hardly surprising, therefore, 
but it probably comes as close as any enterprise ever will to being a science 
of argumentation. 

In this account, Tully sees informal logic as focused on arguments in natural 
language—a familiar enough theme. His list of its tasks lines up with what we have 
seen thus far, with the exception that he introduces Gricean “conversational 
implication.” Informal logic is again pictured as a supplement that gives attention 
to natural language and the fabric of discourse and makes allowance for vagueness, 
assumptions and rhetorical devices. He stresses both the craft of informal logic 
and its inability to attain the precision and elegance of formal logic. 

1997: Brinton and Walton, Historical Foundations of Informal Logic 

This book is the first attempt to write a history of informal logic, about which the 
authors say: 

Informal logic has yet to come together as a clearly defined discipline, one 
organized around some well-defined and agreed upon systematic techniques 
that have a definite structure and that can be decisively applied by users. 



Making Sense of “Informal Logic”     245 

Nothing analogous to the great flowering of formal logic of the past hundred 
years has occurred or appears quite ready to occur in informal logic.25 (9) 

Walton and Brinton stress informal logic’s lack of definition and go on to cite “the 
diversity of thinking” about the issues and problems that fall under its study. They 
cite as a reason that informal logic will not attain the status of formal logic that it is 
a practical subject that requires the interpretation of natural language argumentative 
discourse (9). 

Summation 

We have seen that there are two settings in which the term “informal logic” comes 
to the fore. Historically first but less developed is the setting in which informal 
logic is associated in some way with philosophical analysis (Ryle, Strawson, Grice). 
Here informal logic is contrasted with formal logic for the purpose of helping 
clarify the nature of philosophy, or philosophical analysis. The second setting is 
that in which informal logic is contrasted with formal logic for the purposes of 
developing an alternative approach to (the teaching of) logic, whether these are 
freestanding or incorporated within a more comprehensive treatment. Here we 
find two subtypes. In the first, informal logic is construed as a supplement to 
formal logic (e.g., Carney & Sheer, Goldman, The Oxford Companion). In the 
second, informal logic is conceived as a distinct and autonomous inquiry (e.g., 
Munson, Johnson and Blair, Govier, Walton.) The two subtypes seem independent. 

It is worth noting that there is nothing like a widely cited definition, each author 
appearing to approach the task from his or her own vantage point and background 
of experience, without feeling the need to relate his/her definition to that of others. 
Yet for all that, there is a kind of rough convergence—as I will attempt to exhibit 
below. 

3. Possible explanation of this range 

I suspect the main reason for this range is that the term does not emerge from 
traditional logical inquiry with any fixed meaning; there is no paradigm26 to which 
it clearly and obviously refers, so its meaning is open-ended. The term functions, 
as I said before, as a fluid designator–one to which authors feel comfortable 
attaching their own sense. In both settings, however, the term makes implicit 
reference to formal logic—which does possess a clear meaning and a well- 
established presence. This presence provides the kernel of the explanation of how 
the term acquires its range. 

Formal deductive logic, particularly in the form of mathematical logic, emerged 
at the end of the 19th century as part of an impressive attempt to settle pressing 
issues in the foundations of mathematics. In the 20th century, logic became enmeshed 
in the philosophical program of “analytic philosophy” in many ways. See, for 
example, Russell’s deployment of it in The Philosophy of Logical Atomism, (1918). 
As we have seen,  the term “informal logic” emerged in two settings (sometimes in 



246     Ralph H. Johnson 

philosophy, sometimes in logic) to register dissatisfaction with the analytic program 
for philosophy—a crucial component of which was its appropriation of formal 
deductive logic to provide tools for philosophical analysis.27 

Thus, part of the explanation for the range of meaning stems from the negating 
force of the “in-” which may have any of several focal points (which would in 
turn help to explain the range): 

· In the first setting, it signals a distancing from the reigning notion of the 
    nature of philosophical analysis; i.e., there are limits to formal analysis 

    (Strawson, Ryle, Grice); 

· In the second setting, it signals a move in logic which may take 
    any of a number of forms: 

It may be seen as a distancing from the formalizing tendency, e.g., 
Johnson and Blair, Govier, Walton; or, 
It may be seen as a distancing from the deductivism associated with 
FDL, e.g. Johnson and Blair, Govier, Fogelin; or, 
It may be seen as signaling a switch in the focus of logical theory from 
syntax and semantics to pragmatics, e.g., Walton, Fogelin; or, 
It may be seen as a turn toward seeing argument in a real-life setting as 
opposed to the artificiality of the examples associated with FDL, e.g., 
Munson, Johnson and Blair, Govier. 

This distancing from formal logic—stemming as it does from various sources— 
helps explain the range of meaning we have encountered, as different authors 
chose different points of focus. Yet the identity of informal logic does not reside 
purely in negating, nor can an understanding of it emerge solely from the various 
attempts to explain its meaning. An equally appropriate way to obtain a clearer 
understanding of what “informal logic” means will become clearer if we focus 
attention on its agenda, on what it does. 

4. A closer look at the informal logic approach 

We have seen that in North America the term “ informal logic” came to be associated 
with a new approach to teaching introductory logic courses in university settings. 
A sense of this was palpable in 1978 at First International Symposium on Informal 
Logic. And it was represented in what we called the New Wave tradition of logic 
textbooks. At the same time, informal logic comes to be seen as an approach that 
takes aim at argumentation in natural language, and sees argument as an important 
focus for philosophical reflection (Govier). The result is the emergence of the 
theory of argument (like theory of knowledge) and a developing theoretical literature. 
Because it clearly refers to a variety of quite different approaches, the term cannot 
be said to designate anything like a school. 



Making Sense of “Informal Logic”     247 

A bit more on each of these topics may provide further clarity and perspective. 

In the first instance: a pedagogical revolution 

Historically, informal logic emerged as a revolution, or change, in how 
undergraduate logic courses were taught. I well remember reading a prepublication 
version of the Preface to Howard Kahane’s Logic and Contemporary Rhetoric that 
contained the following statement: 

Today’s students demand a marriage of theory and practice. That is why so 
many of them judge introductory courses on logic, fallacy, and even rhetoric 
not relevant to their interests. 

In class a few years back, while I was going over the (to me) fascinating 
intricacies of the predicate logic quantifier rules, a student asked in disgust 
how anything he’d learned all semester long had any bearing whatever on 
President Johnson’s decision to escalate again in Vietnam. I mumbled 
something about bad logic on Johnson’s part, and then stated that 
Introduction to Logic was not that kind of course. His reply was to ask what 
courses did take up such matters, and I had to admit that so far as I knew 
none did. He wanted what most students today want, a course relevant to 
everyday reasoning, a course relevant to the arguments they hear and read 
about race, pollution, poverty, sex, atomic warfare, the population explosion, 
and all the other problems faced by the human race in the second half of the 
twentieth century. (vii) 

In line with this realization which was dawning (independently) on many other 
logic instructors, the 70s witnessed an explosion of texts that reflected this new 
approach to teaching logic. In our 1980 paper, we referred to this trend as a 
“geist.” We found this new approach manifested in such texts as Kahane, Logic 
and Contemporary Rhetoric, 1970; Stephen Thomas, Practical Reasoning in Natural 
Language, 1972; Scriven, Reasoning, 1976; Munson, The Way of Words, 1976; 
Johnson and Blair, Logical Self-Defense, 1977; Fogelin, Understanding Arguments, 
1978.28 

Defining themes of the new approach 

This new approach to teaching logic was defined by certain themes. Here I articulate 
and itemize only what I take to be the main ones. (For fuller discussion, see 
Johnson and Blair 1996, 2002). 

(i) The dissatisfaction with FDL as a pedagogical approach to teaching students 
how to analyze and evaluate arguments (Johnson and Blair, Scriven); 

(ii) The adoption of a different focus on argument that included defining “argument” 
differently and seeing argument in its habitat, however that is to be characterized: 
ordinary argument, mundane argument, everyday argument, arguments in use) 
(Munson, Johnson and Blair, Fogelin, Scriven, Govier); 



248     Ralph H. Johnson 

(iii) The search for ways of understanding and displaying the structure of argument 
not dependent on the notion of logical form; this search is coupled with a 
dissatisfaction with the deductive-inductive distinction that is associated with 
the positivist research program (e.g., Carnap); 

(iv) The desire to develop a richer approach to argument evaluation. There is 
general agreement that soundness—that condition that is satisfied when an 
argument has all true premises and is valid—is not the proper ideal. This leads 
to the discussion of a better set of criteria and also to taking the fallacies seriously. 
This desire leads gradually to the distinction between premise-adequacy and 
inferential-adequacy;29 

(v) The appreciation of the importance of argument construction: If one is to 
teach students about real arguments, then it is not enough to focus only on 
evaluation; one must include the task of argument construction—an emphasis 
taken from colleagues in rhetoric; 

(vi) The broadening of the scope: If one is to teach students about how to handle 
attempts at persuasion one must broaden one’s scope equipping students to 
handle everyday persuasion. Kahane’s text included chapters on advertising and 
textbooks; Johnson and Blair include chapters on how to obtain information 
from news media and how to deal with advertising; 

(vii) The connection with critical thinking: One other point worth mentioning is the 
connection between informal logic and critical thinking. As it developed this 
new approach to teaching university and college undergraduates about argument, 
the informal logic “movement” became strongly associated with what was called 
the Thinking Skills Movement which was targeting the way in which thinking 
skills were being taught (or not) at all levels, a concern reflected in such issues 
as “Why Johnny Can’t Reason” and “The Fourth R—Reasoning.” Of particular 
importance was the connection between informal logic and the critical thinking 
movement, which happened as follows. In 1981, Blair, Johnson and Scriven all 
attended the Conference on Critical Thinking and Moral Critique hosted by 
Richard Paul. It became clear to those of us working in informal logic that there 
were kindred spirits in this movement. From then through the mid-90s, the 
annual Sonoma Critical Thinking Conference served as an important gathering 
place for the exchange and development of ideas.30 

In the second instance: theoretical developments 

 The movement also began to develop a theoretical literature, which grew out 
of the attempt to pursue the above interests. 

One way to track the development of the theoretical dimension is to canvas the 
Informal Logic Newsletter, where the very first issue to emerge was the adequacy 
of the inductive-deductive distinction: the questioning of that in turn leads to the 
search for the third way; that is, to find a mode of inferential connection neither 
inductive nor deductive: Blair and Johnson (1980). Here I would mention Govier 



Making Sense of “Informal Logic”     249 

(1987)—conductive inference, Scriven (1987)—probative reasoning; Walton 
(1995)—presumptive reasoning.31 Some (Pinto, 2001; Blair, 2007) regard this as 
the most salient task associated with informal logic.32 

A second issue to emerge in the theoretical literature was that of the role of 
interpretation in argument analysis. Informal logicians paid a great deal of attention 
to the task of how to identify missing premises in argument—Scriven (1976), 
Johnson and Blair (1980)—for two reasons. First, in the analysis of real-life 
arguments (as contrasted with the artificial examples that populate formal logic 
textbooks), this often turns out to be an important step. Second, if one parts 
company with FDL, then this task is more complex. Here is how Scriven frames 
the issue: 

I sometimes think that one can best spotlight the gap between formal logic 
and real reasoning by pointing out that almost every real argument involves 
assumptions, but that, as far as I know, there has never been an even 
moderately successful attempt to analyse the concept of an assumption.... 
Without such an analysis, effective criticism of an argument, or an arguer, is 
hopelessly crippled. (xvi) 

This problem in turn led to the awareness of and interest in the principle of charity— 
the question of how to formulate and how to justify the choice of a missing 
premise—a problem that, so far as I know, had never been taken in hand by 
previous generations of logicians. 

A third issue was how to develop a better understanding of fallacy. This work 
had already begun in earnest by Walton and Woods who throughout the 70s produced 
a series of articles in various philosophical journals. These may be seen as a response 
to the gauntlet thrown down by Hamblin (1970). Their work demonstrated that 
fallacy theory was a fruitful area of inquiry. 

Some important landmarks in the developing theoretical literature are the 
publication of Trudy Govier, Problems in Argument Analysis and Evaluation (1987) 
Douglas Walton, Informal Logic (1989); Alec Fisher, The Logic of Real Arguments 
(1989), Hans V. Hansen, “An Informal Logic Bibliography” (1990), James Freeman, 
Dialectics and the Macrostructure of Argument (1991); Hans V. Hansen and Robert 
C. Pinto, Fallacies (1995), Ralph H. Johnson, The Rise of Informal Logic (1996).33 

 Two points need to be made about this pattern of development. First, in the 
informal logic movement, practice gives rise to theory, along the lines suggested 
by Munson (p. 251). It sets the stage for theoretical developments: 

With one eye riveted on our argumentative practices, informal logic began 
the process of attempting to develop a better theory. In this way informal 
logic illustrates a pattern of development which is the very reverse of that 
proposed by Massey…. In informal logic, the theory develops out of the 
practice. The significance of informal logic lies in part in its attempt to 
bridge the gap from the side of practice rather than theory, to build theory 
out of practice. (Johnson, 2000) 



250     Ralph H. Johnson 

And here we have the final piece of the puzzle to explain the heterogeneity of 
conceptions of informal logic. For how one would conceive of informal logic 
depended to some degree on which aspect of argumentative practice the individual 
author thought required attention. 

 Second, in this developing theoretical literature, one can see more clearly some 
important features of informal logic that may not be so evident in the pedagogical 
strand. 

(A) Informal logic in relationship to other disciplines and initiatives 

Formal logic: Though informal logic in the first instance distances itself from 
formal logic, yet as we have seen there is developing awareness of a relationship 
between the two—Walton (1990). Johnson (1999) contrasts informal logic as 
concerned with argument with formal logic as concerned with implication/entailment. 

Critical Thinking: Since the 80s, informal logic has been partnered, in the 
minds of many, with critical thinking and indeed some seem to equate the two, 
though it is clear that they are different, though related. Critical thinking is, in the 
first instance, a kind of activity, or mental practice, whereas informal logic is a 
kind of inquiry or theory. Critical thinking also designates an educational ideal that 
emerged with great force in the 80s in North America as part of an ongoing critique 
of education as regards the thinking skills not being taught. The precise definition 
of “critical thinking” is a subject of much dispute (Johnson, 1992) but all will 
agree that in order to think critically one must be able to process arguments. That 
is where informal logic comes into play. While much of critical thinking will focus 
on arguments (because one has to grapple with reasons for and reasons against) 
and hence require skills of argumentation, critical thinking requires additional abilities 
not supplied by informal logic: the ability to obtain and assess information, to 
clarify meaning. Also many believe that critical thinking requires certain dispositions 
(Ennis, 1987). It was also tempting for many to conflate critical thinking with 
problem solving. I take these issues to be part of the Network Problem (Johnson, 
2000) and to require for their proper settlement a theory of reasoning. 

Epistemology: Historically, many of the philosophers who took an interest in 
informal logic did so from an epistemological interest and background. See Weinstein 
(1990) Pinto (1994), Siegel (1994). There are obvious ways in which the two are 
related: the notion of justification, the interest in rationality, the truth issue; but 
there are ways in which they remain and must remain different (Johnson and Blair, 
1996)—notwithstanding the views of those who argue that informal logic is applied 
epistemology (Weinstein, 1994). 

Rhetoric and Communication Studies: Rhetoric has been concerned with 
argumentation particularly from the perspective of persuasion—which is of special 
concern to informal logic. Likewise the move away from truth and toward 
acceptability as a requirement for premise adequacy leads to greater attention paid 
to the role of the audience—as does the interest in argument construction mentioned 
above. 



Making Sense of “Informal Logic”     251 

Linguistics: Argumentation is or may be viewed as a speech act, as, for example, 
Pragma-Dialectics views it; or as a form of linguistic activity (Grize, 1982). 

Argumentation Theory: Informal logic also became strongly associated with 
an initiative often referred to as Argumentation Theory. One of the first indicators 
of this area of inquiry was the emergence of the Pragma-dialectical approach to 
argumentation developed by two Dutch linguists—Frans van Eemeren and Rob 
Grootendorst. It became clear that informal logic was part of a worldwide network 
of researchers, all interested in the study of argumentation—an inquiry known as 
Argumentation Theory. The conferences that they began in Amsterdam in 1986 
and that have been held every four years since have functioned as a focal point for 
those interested in the study of argumentation. Scholars from all over the world 
with various backgrounds and approaches to the study of argumentation gather to 
exchange views. 

Computer Science: There is now evidence of contact between informal logic 
and computer science, mediated by argumentation theory and dialogue logic. 
Informal logic drives much of argumentation theory, and argumentation is now a 
subject that computer scientists have taken in hand. See Argumentation Machines: 
New Frontiers in Argument and Computation, Chris Reed and Timothy Norman 
(Eds.) (2004). A similar tie connects informal logic to initiatives in the logic of 
practical reasoning research program. In addition to the already-mentioned 
Handbook of the Logic of Argument and Inference, see also the multi-volume 
work of Gabbay and Woods, under the generic title: A Practical Logic of Cognitive 
Systems (2003, 2005, and forthcoming). 

Thus one of the important features of informal logic has been the number of 
cross-fertilizations it has achieved (and benefited from) with other disciplines.34 

(B) Informal logic as positioned between formal logic and rhetoric 

One of the merits, I believe, of the informal logic approach to argument has been 
its positioning of itself between the (excessively) abstract universalist approach 
taken in FDL (a theory where one size fits all), and the more contextualized and 
nuanced approaches found in rhetoric and speech communication—which are 
highly context sensitive. In my account, informal logic retains some of the universalist 
tendencies of formal logic; it aims to give an account of argument worth that is 
applicable across the board. At the same time, informal logic is also more open to 
the need to pay attention to the details provided by context that is typical of rhetorical 
approaches. It does not share the ancient philosophical distrust for rhetoric discussed 
by Tindale (this issue), though the attempt to strike a balance is something of a 
tightrope act. 



252     Ralph H. Johnson 

(C) Informal logic as pragmatic 

Another filter through which to view the development of informal logic is the 
traditional distinction (due to Morris) between syntax (syntactics), semantics, and 
pragmatics. Syntax is the study of the relation of signs to other signs; semantics is 
the study of signs to the things they represent; and pragmatics is the study of the 
relations of signs to their users (The Oxford Companion, 820). With pragmatics, 
agency is back in the picture.35 

It is clear that informal logic is closely related to pragmatics. The tasks of 
reconstructing an argument, of supplying missing premises, of clarifying meaning— 
all of these tasks fall within the domain of pragmatics—rather than syntax or 
semantics. Scriven (1980) sounded this note in his paper for the First International 
Symposium when he said: “It has long been obvious that the concept of explanation, 
in science or elsewhere, is neither syntactic nor semantic but essentially pragmatic 
(to use a traditional set of terms that are themselves somewhat contaminated by 
formalism)” (p.150). Thus, informal logic lines up well with the most recent stage 
in the ongoing development of logic in this century in which pragmatics emerges 
as a key player. 

5. Conclusion 

In a sense, this paper has been an exercise in intellectual history, an attempt to 
understand how a specific term—”informal logic”—came to be interpreted in so 
many different ways. I hope my attempt to explain the many different meanings, 
how they emerged and how they are related has been helpful. This paper is also, to 
some degree, an account of a movement that developed outside the mainstream of 
philosophy,36 whose origins lie in a desire to make logic useful (echoing Dewey) 
and which developed into an important challenge to conventional views about 
argument. Given the emergence of informal logic and its importance, it is difficult 
to understand its failure to achieve deeper penetration of the philosophical 
establishment (Woods, 2000). But that is a matter for another paper. 

Notes 
1 This paper relies on earlier attempts by Johnson and Blair to chart the history of informal logic, 
especially Chapter VIII in The Handbook of the Logic of Argument and Inference (2002). In 
addition, I want to thank Tony Blair, Chris Tindale, Hans V. Hansen and Bob Pinto for their 
comments on earlier drafts. Thanks are due also to two referees for this journal for their comments, 
as well as to Michael Scriven, Ronald Munson, Takuzo Konishi,Thomas Fischer, Leo Groarke 
and Lenore Langsdorf. John Woods made extensive and helpful comments and suggestions from 
which I hope to have benefited. Finally, I want to thank my student assistant, Michael Baumtrog— 
the Bommer—for his helpful comments and able assistance. 
2 This is Hansen’s term (private conversation). 
3 My focus here will be the term “informal logic” but I will occasionally refer to the referent— 
informal logic. 



Making Sense of “Informal Logic”     253 

4 I set to one side here what I think of as eccentric uses—like this one: “Culture is here taken to 
refer to what Clifford Gertz has described as ‘the informal logic of actual life’ (Vincent, 1989, p. 
7.). 
5 The existence of informal logic has been questioned (Johnson, 2000,252 ff.), just as has been the 
case with inductive logic. 
6 A Google Search conducted in January 2007 showed 4,190,000 hits for informal logic; 17,400,000 
for formal logic; 4,550,000 for fuzzy logic; 471,000 for epistemic logic. 
7 In fact Grice holds that both the formalist and the informalist are guilty of an assumption that he 
is going to challenge. 
8 The treatment that follows on pp. 249-53 is largely that from Johnson and Blair (2002), pp 28ff. 
9 The abbreviation “FDL” stands for “formal, deductive logic.” I introduced this acronym in 
(1986) for the purposes of contrasting informal logic’s approach to argument with that taken by 
those favoring a formal approach in which the ideal is soundness. Subsequently I came to understand 
that the focus of my complaint was not formal deductive logic itself but rather textbooks in which 
FDL had in effect been downloaded and refurbished and made to function as a theory of argument, 
which in my view, it was never intended to do. To explain how this happened would take us too 
far a field. The point here is that some derision was intended in coining “FDL” reflecting perhaps 
the mentality of many of us in those early days. My considered view of the matter is found in 
(1999). 
10 Here is Munson’s own account of the origin of the definition he offered: “I know from having 
studied the history of science that all concepts and definitions have antecedents, but I made up the 
definition of “informal logic” without knowingly drawing on any other definition…. The phrase 
was not at that time in currency, and people I knew about who wrote about the topics usually did 
so in large books devoted to syllogistic logic and rhetoric. I was trained as a philosopher of 
science, and I modeled my definition on what I believed to be the major activity of philosophers 
of science, seen from the point of view of logical empiricism—to understand the logic and 
language of science by making explicit rules underlying practice. That’s why you see in my definition 
the reference to rules implicit in practice. I was concerned to convey to readers the idea that 
informal logic wasn’t a set of arbitrary conventions imposed by philosophers, but was, rather, an 
analysis (or reflection) of what they did already without necessarily being aware of it.” (private 
correspondence, included here with the author’s permission, emphasis added) 
11 Govier (1999) notes that “one common account of argument cogency is that of acceptability, 
relevance or sufficiency (or good grounds), which may be abbreviated ARG” (98). In her endnote, 
she says: “The ARG abbreviation is my own and I use it in A Practical Study of Argument. The 
original account of acceptability, relevance and sufficiency was put forward by Johnson and Blair 
(1983)” (103). In fact, this account was first put forward in Johnson and Blair (1977) and appears 
later in a revised form in Govier (1985) in which she changes sufficiency to adequacy. Others who 
have adopted some form of the RSA account of criteria for the evaluation of argument include: 
Damer (1987), Freeman (1988), Little, Groarke and Tindale (1989), Barry (1992) and Seech 
(1992). This account of argument evaluation may with some justice be said to be one of the 
identifying traits of informal logic. 
12 Most of these articles are collected in Woods & Walton (2007). The fallacies are also a major 
focus of their textbook, Argument: The Logic of the Fallacies (1982). 
13 This treatment based on Johnson & Blair (2002). However, I would frame the contrast here 
differently now: the theory of fallacy is not separate from the theory of argument, but rather a 
part of it. It is part of the theory of evaluation. See Johnson (2000: 40-41). 
14 Woods’ views have evolved over time. If his position in 1980 was that nothing is informal logic, 
his position in 2004 is that the applicability of a formal logic to natural language argumentation is 
lodged in a prior logic which is (rightly) irreducibly informal. See Chapters 2 and 3 of (2004a). 
15 Note the disjunctive pairing. I believe that Copi was introduced to informal logic in the 1980s 



254     Ralph H. Johnson 

as a result of the critical thinking initiative in California (spearheaded by Richard Paul at Sonoma 
State University) where informal logic and critical thinking came together. Thus Copi tends to link 
the two—a linkage encouraged by the existence of the Association for Informal Logic and Critical 
Thinking (AILACT), born in 1983 at the Second International Symposium on Informal Logic. 
16 See Wayne Grennan’s review of Copi’s Informal Logic in IL 9, 50-51, which makes a similar 
point. 
17 Harman takes a view similar to this in his (1986). 
18 I have no disagreement with Goldman on the importance of these tasks. The difference between 
us is that I see the task of developing principles of good reasoning as the generic task of logic—not 
of informal logic specifically—and the task of clarifying the relationship between good reasoning 
and formal logic as the task of the theory of reasoning—rather than one I would relegate to 
informal logic which I take to be the logic of argument (as distinguished from both inference and 
implication). See 2000, 24-25, 92-94. 
19 As has been noted, one problem with this definition is its apparent circularity—defining 
“informal” with “non-formal.” To my mind, this is really a less serious problem than the failure 
to clarify the sense of “ formal” negated by the “in.” See my (2000, 119-20) and Johnson and Blair 
(2002, 358-59) for an attempt to do that. The evolution from the (1980) articulation is partly the 
result of the influence of Finocchiaro (1984)—though he takes informal logic to be a theory of 
reasoning, whereas we take it to be a theory of argument. 
20 I do not mean to ignore Govier’s Problems in Argument Analysis and Evaluation (1987). But 
this is really a collection of individual papers published on different occasions rather than a 
monograph. 
21 The idea is there in Fogelin but not thematically developed. Walton also had sounded this note 
earlier. 
22 Scriven (1976), Johnson and Blair (1977), Fogelin (1978) Govier (1985), Fisher (1988). 
23 In Manifest Rationality, I addressed how informal logic fares with respect to the semantics/ 
syntax/pragmatics distinction. See pp. 368-69. 
24 I want to thank Takuzo Konishi for calling this text to my attention. I omit the account in The 
Cambridge Dictionary of Philosophy because it was written by Walton, whose views have been 
sufficiently covered. 
25 In a subsequent paper I intend to address the issue of the lack of development in informal logic. 
26 I mean the term in its Kuhnian sense 1962: (10ff). 
27 This is not to ignore inductive logic (a la Carnap, for example), but I submit that the ideal of 
argument for most of those engaged in the positivist research program is that of soundness. 
28 An aside about the textbook habitat: Weinstein criticized this development (1993), suggesting 
that the authors of these texts were motivated chiefly by financial concerns—”they’re only in it 
for the money.” But there are other and better explanations for the proliferation of texts: the 
pedagogical thrust of the initiative combined with the lack of an appropriate journal for publishing 
new materials made textbooks the scene of some important conceptual innovations. And it says 
something about the informal logic initiative that Copi—the most successful textbook author in 
logic textbook history—decided to publish a textbook by that name—Informal Logic—in 1986. 
Finally, it is worth noting that some of the most illustrious philosophers in the 20th have published 
textbooks. To name just a few: Quine (1948), Rescher (1964), Scriven (1976), Toulmin (1979). I 
doubt that these philosophers were motivated by the idea of making money. 
29 The present author would add dialectical adequacy to the list and has registered his reservations 
about the idea of inferential adequacy. 
30 Important here was the birth of AILACT (The Association for Informal Logic and Critical 
Thinking) at the Second International Symposium on Informal Logic (Windsor, 1983), as well as 
the conferences hosted by John Hoaglund in the mid-80s at Christopher Newport College in 



Making Sense of “Informal Logic”     255 

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Ralph H. Johnson 
Centre for Research in Reasoning, Argumentation and Rhetoric 

Department of Philosophy 
University of Windsor 

Windsor, ON, N9B 3P4 

johnsoa@uwindsor.ca