Excerpted from Current Issues & Enduring Questions: A Guide To Critical Thinking and Argument, with Readings by Sylvan Barnet and Hugo Bedau, Bedford/St. Martin's : Boston, MA. 1999

The Toulmin Model

We reason in two main ways:

Both types of reasoning share some structural features, as we also noticed. Thus, all reasoning is aimed at establishing some thesis (or conclusion) and does so by means of some reasons. These are two basic characteristics that any argument contains.

They are as follows:

The Claim

Every argument has a purpose, goal, or aim, namely to establish a claim (conclusion or thesis). Suppose you were arguing in favor of equal rights for women. You might state your thesis or claim as follows:

Men and women ought to have equal rights.

A more precise formulation of the claim might be

Men and women ought to have equal legal rights.

A still more precise formulation might be

Equal legal rights for men and women ought to be protected by our Constitution.

The third version of this claim states what the controversy over the Equal Rights Amendment was all about.

Consequently, in reading or analyzing someone else's argument, your first question should naturally be: What is the argument intended to prove or establish? What claim is it making? Has this claim been clearly and precisely formulated, so that it unambiguously asserts what its advocate wants to assert?


Once we have the argument's purpose or point clearly in mind and thus know what the arguer is claiming to establish, then we can ask for the evidence, reasons, support, in short, for the grounds on which that claim is based. In a deductive argument these grounds are the premises from which the claim is deduced; in an inductive argument the grounds are the evidence -- a sample, observation, or experiment -- that makes the claim plausible or probable.

Obviously not every kind of claim can be supported by every kind of ground, and conversely, not every kind of ground gives equally good support for every kind of claim. Suppose I claim that half the students in the classroom are women. I can ground this claim in any of several ways.

(1) I can count all the women and all the men. Suppose the total equals fifty. If the number of women is twenty-five, and the number of is twenty-five, I have vindicated my claim.

(2) I can count a sample of, say, ten students, and find that in the sample, five of the students are women, and thus have inductive --plausible but not conclusive -- grounds for my claim.

(3) I can point out that the students in the college divide equally into men and women, and claim that this class is a representative sample of the whole college.

Obviously ground (1) is stronger than ground (2), and (2) is far stronger than ground (3).

Now we want to consider four additonal features of arguments.


Once we have the claim or the point of an argument fixed in mind, and the evidence or reasons offered in its support, the next question to ask is why these reasons support this conclusion. What is the warrant, or guarantee, that the reasons proffered do support the claim or lead to the conclusion? In simple deductive arguments, the warrant takes different forms, as we shall see. In the simplest cases, we can point to the way in which the meanings of the key terms are really equivalent. Thus, if John is taller than Bill, then Bill must be shorter than John because of the meaning in English of "is shorter than" and "is taller than." In this case, the warrant is something we can state quite literally and explicitly.

In other cases, we may need to be more resourceful. A reliable tactic is to think up a simple parallel argument, that is, an argument exactly parallel in form and structure to the argument we are trying to defend. We then point out that if we are ready to accept the simpler argument then we must accept the more complex argument because both arguments have exactly the same structure. For example, in her much-discussed essay of 1972 on the abortion controversy, "A Defense of Abortion," philosopher Judith Thomson argues that a pregnant woman has the right to an abortion to save her life, even if it involves the death of her unborn child. She anticipates that some readers may balk at her reasoning, and so she offers this parallel argument: Suppose you were locked in a tiny room with another human being, which through no fault of its own is growing uncontrollably, with the result that it is slowly crushing you to death. Of course it would be morally permissible to kill the other person to save your own life. With the reader's presumed agreement on that conclusion, the parallel argument concerning the abortion situation -- so Thomson hopes --is obvious and convincing.

In simple inductive arguments, we are likely to point to the way in which observations or sets of data constitute a representative sample of a whole (unexamined) population. Here, the warrant is the representativeness of the sample. For instance, in projecting a line on a graph through a set of points, we defend one projection over alternatives on the ground that it makes the smoothest fit through most of the points. In this case, the warrant is simplicity and inclusiveness. Or in defending one explanation against competing explanations of a phenomenon, we appeal to the way in which the preferred explanation can be seen as a special case of generally accepted physical laws.

Establishing the warrants for our reasoning -- that is, explaining why our grounds really support our claims -- can quickly become a highly technical and exacting procedure that goes far beyond what we can hope to explain in this book. Only a solid course or two in formal deductive logic and statistical methods can do justice to our current state of knowledge about these warrants. Developing a "feel" for why reasons or grounds are or are not relevant to what they are alleged to support is the most we can hope to do here without recourse to more rigorous techniques.

Even without formal training, however, one can sense that something is wrong with many bad arguments. Here is an example. British professor C. E. M. Joad found himself standing on a station platform, annoyed because he had just missed his train, when another train, making an unscheduled stop, pulled up to the platform in front of him. He decided to jump aboard, only to hear the porter say "I'm afraid you'll have to get off, sir. This train doesn't stop here." "In that case," replied Joad, "don't worry. I'm not on it."


The kinds of reasons appropriate to support an amendment to the Constitution are completely different from the kinds appropriate to settle the question of what caused the defeat of Napoleon's invasion of Russia. Arguments for the amendment might be rooted in an appeal to fairness, whereas arguments about the military defeat might be rooted in letters and other documents in the French and Russian archives. The canons of good argument in each case derive from the ways in which the scholarly communities in law and history, respectively, have developed over the years to support, defend, challenge, and undermine a given kind of argument. Thus, the support or backing appropriate for one kind of argument might be quite inappropriate for another kind of argument.

Another way of stating this point is to recognize that once you have given reasons for a claim, you are then likely to be challenged to explain why these reasons are good reasons -- why, that is, one should believe these reasons rather than regard them skeptically. Why (a simple example) should we accept the testimony of Dr. X when Dr. Y, equally renowned, supports the opposite side? Or: Why is it safe to rest a prediction on a small though admittedly carefully selected sample? Or: Why is it legitimate to argue that (a) if I dream I am the King of France then I must exist, whereas it is illegitimate to argue that (b) if I dream the King of France, then the King of France must exist? To answer these kinds of challenges is to back up one's reasoning, and no argument is any better than its backing.

Modal Qualifiers

As we have seen, all arguments are made up of assertions or propositions, which can be sorted into four categories:

the claim (conclusion, thesis to be established),

the grounds (explicit reasons advanced),

the warrant (the principle that connects the ground to the claim), and

the backing (implicit assumptions).

All these kinds of propositions have an explicit or tacit modality in which they are asserted, indicating the scope and character with which they are believed to hold true. Is the claim, for instance, believed to be necessary -- or only probable? Is the claim believed to be plausible -- or only possible? Of two reasons for a claim, both may be good, but one may be better than the other. Indicating the modality with which an assertion is advanced is crucial to any argument for or against it.

Empirical generalizations are typically contingent on various factors, and it is important to indicate such contingencies to protect the generalization against obvious counterexamples. Thus, consider this empirical generalization

Students do best on final examinations if they study hard for them.

Are we really to believe that students who study regularly throughout the whole course and so do not need to cram for the final will do less well than students who neglect regular work in favor of several all-nighters at the last minute? Probably not; what is really meant is that all other things being equal (in Latin, caeteris paribus), concentrated study just before an exam will yield good results. Alluding to the contingencies in this way shows that the writer is aware of possible exceptions and that they are conceded right from the start.

Assertions also have varying scope, and indicating their scope is equally crucial to the role that an assertion plays in argument. Thus, suppose you are arguing against smoking, and the ground for your claim is this:

Heavy smokers cut short their life span.

Such an assertion will be clearer, as well as more likely to be true, if it is explicitly quantified. Here, there are three obvious alternative quantifi-cations to choose among: all smokers cut short their life span, or most do, or only some do. Until the assertion is quantified in one of these ways, we really do not know what is being asserted-and so we do not know what degree and kind of evidence and counterevidence is relevant.

In sum, sensitivity to the quantifiers and qualifiers appropriate for each of our assertions, whatever their role in an argument, will help prevent you from asserting exaggerations and other misguided gener-alizations.


Very few arguments of any interest are beyond dispute, conclusively knockdown affairs, in which the claim of the argument is so rigidly tied to its grounds, warrants, and backing, and its quantifiers and qualifiers so precisely orchestrated that it really proves its conclusion beyond any possibility of doubt. On the contrary, most arguments have many counterarguments, and sometimes it is one of these counterarguments that is the more convincing.

Suppose one has taken a sample that appears to be random -- an interviewer on your campus accosts the first ten students whom she sees and seven of them happen to be fraternity or sorority members. She is now ready to argue: Seven-tenths of the student body belong to Greek organizations.

You believe, however, that the Greeks are in the minority and point out that she happens to have conducted her interview around the corner from the Panhellenic Society's office just off Sorority Row. Her random sample is anything but. The ball is now back in her court as you await her response to your rebuttal.

As this example illustrates, it is safe to say that we do not understand our own arguments very well until we have tried to get a grip on the places in which they are vulnerable to criticism, counterattack, or refutation. Edmund Burke said, "He that wrestles with us strengthens our nerves, and sharpens our skill. Our antagonist is our helper." Therefore, cultivating alertness to such weak spots, girding one's loins to defend at these places, always helps strengthen one's position.

Model Analysis Using the Toulmin Method

In order to see how the Toulmin method can be used, let's apply it to an argument in this book, Susan Jacoby's "A First Amendment Junkie," page 29.

The Claim Jacoby's central thesis or claim is this: Any form of censorship --including feminist censorship of pornography in particular -- is wrong.

Grounds Jacoby offers six main reasons or grounds for her claim roughly in this sequence (but arguably not in this order of importance).

First, feminists exaggerate the harm caused by pornography because they confuse expression of offensive ideas with harmful conduct.

Second, letting the government censor the expression of ideas and attitudes is the wrong response to the failure of parents to control the printed materials that get into the hands of their children.

Third, there is no unanimity even among feminists over what is pornography and what isn't.

Fourth, permitting censorship of pornography, in order to please feminists, could well lead to censorship on many issues of concern to feminists ("rape, abortion, menstruation, contraception, lesbianism").

Fifth, censorship under law shows a lack of cuilfidence in the democratic Process.

Finally, censorship of words and pictures is suppression of self-expression, and that violates the First Amendment.

Warrants The grounds Jacoby has offered provide support for her central claim in three ways, although Jacoby (like most writers) is not so didactic as to make these warrants explicit.

First, since the First Amendment protects speech in the broadest sense, the censorship that the feminist attack on pornography advocates is inconsistent with the First Amendment.

Second, if feminists want to be consistent, then they must advocate the censorship of all offensive self-expression; but such a radical interference with free speech (amounting virtually to repeal of the First Amendment) is indefensible.

Third, feminists ought to see that they risk losing more than they can hope to gain if they succeed in censoring pornography, because antifeminists will have equal right to censor the things they find offensive but that many feminists seek to publish.

Backing Why should the reader agree with Jacoby's grounds? She does not appeal to expert authority, the results of experimental tests or other statistical data, or the support of popular opinion. Instead, she relies principally on two things -- but without saying so explicitly.

First, she assumes that the reader accepts the propositions that freedom of self-expresion is valuable and that censoring self-expression requires the strongest of reasons. If there is no fundamental agreement on these propositions, several of her reasons cease to support her claim.

Second, she relies on the reader's open-mindedness and willingness to evaluate commonsense (untechnical, ordinary, familiar) considerations at each step of the way. She relies also on the reader having had some personal experience with erotica, pornography, and art. Without that open-mindedness and experience, a reader is not likely to be per-suaded by her rejection of the feminist demand for censorship.

Modal Qualifiers Jacoby defends what she calls an "absolute interpretation of the First Amendment, that is, the view that all censorship of words, pictures, ideas is not only inconsistent with the First Amendment, it is also politically unwise and morally objectionable. She allows that some pornography is highly offensive (it offends her, she insists); she allows that some pornography ("kiddie porn") may even be harmful to some viewers. But she also insists that more harm than good would result from the censorship of pornography. she points out that some paintings of nude women are art, not pornography; she implies that it is impossible to draw a sharp line between permissible erotic pornography and impermissible offensive pornography. She clearly believes that all Americans ought to understand and defend the First Amendment under the "absolute interpretation" she favors.

Rebuttals Jacoby mentions several objections to her views, and perhaps the most effective aspect of her entire argument is her skill in identifying possible objections and meeting them effectively. (Notice the diversity of the objections and the various ways in which she replies.)

Objection: Some of her women friends tell her she is wrong.

Rebuttal: She admits she's a "First Amendment junkie" and she doesn't apologize for it.

Objection: "Kiddie porn" is harmful and deserves censorship

Rebuttal: Such material is not protected by the First Amendment because it is an "abuse of power" of adults over children.

Objection: Pornography is a form of violence against women, and therefore it is especially harmful.

Rebuttal: (a) No, it really isn't harmful, but it is disgusting and offensive. (b) In any case, it's surely not as harmful as allowing American neo-Nazis to parade in Jewish neighborhoods. (Jacoby is referring to the march in Skokie, Illinois, in 1977, upheld by the courts as permissible political expression under the First amendment despite its offensiveness to survivors of the Nazi camps.)

Objection: Censoring pornography advances public respect for women.

Rebuttal: Censoring Ms. magazine, which antifeminists ave already done, undermines women's freedom and self-expression.

Objection: Reasonable people can tell pornography when they see it, so censoring it poses no problems.

Rebuttal: Yes, there are clear cases of gross pornography; but there are lots of borderline cases, as women themselves prove when they disagree over whether a photo in Penthouse is offensive, erotic or "lovely" and "sensuous."

A Checklist For Using The Toulmin Method

· What claim does the argument make?

· What grounds are offered for the claim?

· What warrants the inferences from the grounds to the claim?

· What backing supports the claims?

· With what modalities are the claim and grounds asserted?

· To what rebuttals are the claims, grounds, and backing vulnerable?