In The Uses of Argument, Stephen Toulmin presents a general description of the structure of argumentative passages, “the layout of argument” (1958, Chap. III, p. 94-145). This very influential representation is also known as “Toulmin Schema”, “Toulmin Model of Argument” or “Toulmin Argument Pattern” (TAP).
1. The structure of the prototypical argumentative dialogue and monologue
1.1 Argumentation as a polyphonic monologue
The following passage is an elementary argumentative cell, putting together the basic components of argumentative discourse according to Toulmin:
— Harry was born in Bermuda, so, presumably, Harry is a British subject
— Since a man born in Bermuda will generally be a British subject,
on account of the following statutes and other legal provisions ‘…’
— Unless both his parents were aliens / he has become a naturalized American/…(id., p. 103)
The layout of argument combines two major components:
— A central, affirmative component.
— A negative component, staging a challenging voice, that details the “circumstances in which the general authority of the warrant would have to be set aside.” (Id., p. 101)
1.2 Argumentation as dialogue
This discourse can be re-played as a prototypical argumentative dialogue, starting from a question, asked by some investigating third party, and developing under the pressure exerted by a challenger.
(i) An Issue
Question: — What is the nationality of Harry?
(ii) A Claim — The arguer answers that:
Arguer: — “Harry is a British subject” (ibid., p. 99).
Making this assertion, the arguer “[is thereby committed] to the claim which any assertion necessarily involves”. As a Claim (C), it can be “challenged”:
Challenger: — “What have you got to go on?” (ibid. p. 98)
(iii) Data — In defense, the arguer “must be able to establish [the Claim] — that is, make it good and show that it was justifiable. How is this to be done?” (Id., p. 97): “we shall normally have some facts to which we can point in its support” (ibid.). Here, the arguer gives a fact, or Data (D) to justify the answer:
Arguer: — Harry was born in Bermuda.
Toulmin’s layout is clearly built on a dissensus background. A Claim is “a demand for something rightfully or allegedly due” (WCD, Claim): a claim is put forward in the context of a contestation “to lay claim to, to assert one’s right or title to” (Ibid.).
Data are “things known or assumed; facts or figures from which conclusions can be inferred” (WCD, Data). The quest for data is led with some claim in mind, S. Justification.
Data and Claim are correlative words: Claims require Data, and Data is sought for and selected in function of Claims; they are explicitly connected through a Warrant.
(iv) Warrant — The challenger can still consider that the answer is not fully satisfactory, and “[require]” the speaker to indicate “the bearing on [his/her] conclusion of the data already produced” (id., p. 98):
Challenger: — “How do you get there?” (Ibid.)
The arguer is now required to give a Warrant (W), that is “some rule, principle or inference license” (Ibid.):
Arguer: — “A man born in Bermuda will be a British subject” (id., p. 99).
Now the inquisitive challenger may be “dubious” “whether the warrant is acceptable at all” (id., p. 103):
Challenger: — “You presume that a man born in Bermuda can be taken to be a British subject; […] why do you think that?” (Ibid.).
A warrant is an “authorization or sanction, as by a superior or the law” (WCD, Warrant): the “argument — conclusion” gap is sutured by some authority. It can also be “a justification or reasonable grounds for some act, course, statement or belief” (ibid.). In that case, the warrant would correspond itself to a good reason added to the data; it is generally a law orienting the fact as a data for this claim.
Another warrant would give a different orientation to the same data. For example, the warrant “In Bermuda from late May to October, the climate can be uncomfortably hot and with especially high humidity” would orient the same fact toward the claim “Harry certainly knows how to behave under a humid subtropical climate”.
(v) Backing — The arguer is now required to give a Backing (B), making the Warrant acceptable
Arguer: — I say that “on account of the following statutes and other legal provisions: …” (id., p. 105).
(vi) Qualifier – Rebuttal — For the preceding moves, the challenger asked for formal clarifications; now, he or she turns to substantial objections, such as:
Challenger: — But “special facts may make this case an exception to the rule, or one in which the law can be applied only subject to certain qualifications” (id., p. 101).
Finally the arguer acknowledges these reservations. His or her Claim is a “presumption”, only “presumably” true, not “necessarily” so. This must be clearly expressed by a Qualifier (Q), “indicating the exceptional conditions which might be capable of defeating or rebutting the warranted conclusion (R)”:
Arguer: — My claim (C) is probably true, insofar we don’t know if “both his parents were aliens [or] he has become a naturalized American” (id. p. 102-103).
The Rebuttal articulates the conditions that, if met, would cancel the reasoning. In integrating the challenger’s contributions into his or her reasoning, the speaker introduces co-operation in a situation of inquiry.
The Qualifier should not be considered as the expression of a vague mental restriction, just in case things do not turn out as expected. It is the trace of substantial Rebuttals, not just any face-saving softener or mitigator; these terms would not express the link with the substantial rebutting counter-discourse.
Toulmin articulates these six basic elements in the following diagram
The chain “Data — Warrant — Backing — Claim” represents the positive component of the model.
The combination “Qualifier + Rebuttal” represents the negative, or default@ component of the model.
3.1. A legal syllogism
Toulmin speaks of his approach to argument as “generalized jurisprudence” (, p. 7). The instance of reasoning illustrating the layout of argumentation corresponds to a legal syllogism, where a law is applied to a fact.
Law: Any motorist crossing the yellow line is an infraction and will be fined
Recorded fact: X has crossed the yellow line
Conclusion: This is a violation of the Law and will be accordingly fined
Unless X was driving a fireman’s car, an ambulance… on a mission; was participating in a formal parade…; road works were in progress…
The positive component articulates a premise with a general subject (a law), a premise with a concrete subject (or singular proposition, the argument) in order to deduce a proposition with a concrete subject (the conclusion). It corresponds to a categorization@ process, including an individual into a class, and therefore authorizing the attribution to the individual of the properties and stereotypes characterizing the class. Toulmin’s basic example draws attention to the importance of categorization and intracategorial deduction in ordinary argumentative activity. Nonetheless, the warrants are not restricted to categorizing principled. Actually, a Warrant is an instantiation of an argument scheme@.
3.2 The “rediscovery of the topoi”
The Warrant corresponds to the traditional argumentative notion of topos (Bird 1961), or argument scheme@. A topos is a general statement “warranting” the acceptability of the argument and capable of generating an infinity of particular arguments or enthymemes having the same form.
Ehninger and Brockriede have shown how the concept of warrant could cover the main forms of argument schemes, for example “authoritative arguments” (, p. 293):
— (D) Klaus Knorr states “Soviet leaders calculate that a minor build-up of nuclear power in the NATO countries of Western Europe will add only marginally to the danger of American striking power.
— therefore (C) Soviet leaders calculate that a minor build-up of nuclear power in the NATO countries of Western Europe will add only marginally (to the danger of American striking power).
— Since (W) what Knorr says about the power of nuclear weapons is reliable
— Because (B) Knorr is a professor at Princeton’s Center of International Studies / is unbiased / has made reliable statements on similar matters in the past / etc.
Unless (R) Other authorities more qualified than Knorr say otherwise / special circumstances negate or reduce Knorr’s usual reliability as a witness.
Accordingly, the specific objections and counter-discourses attached to a given argument scheme will come under the Qualifier – Rebuttal subsystem.
3.3 Open foundations
Let us suppose that Harris was born not in Bermuda but in the Falkland Islands (English name) also called Islas Malvinas (Argentine name). Then, the Backing mentioning the statutes on British nationality, would possibly be supplemented by an evocation of the right of occupation, conquest and the right of the strongest, considering the complex history of the islands.
Basing the Warrant on a Backing opens a potential regression to infinity, the guarantee needing itself to be guaranteed. The same regression could be observed on the argument, which may also be challenged.
3.4 Scientific calculation and the erasing of the rebuttal component
Toulmin’s layout is a favorite among scientists interested in argument. The following example, which is less often quoted than the preceding one, corresponds to the expression of a scientific prediction based on a calculation involving laws derived from experience and observation (1958, p. 184):
The general premise is replaced by a calculus based on physical laws. The disappearance of counter-discourse (Modal + Rebuttal) characterizes the transition to mathematical calculus based upon stabilized scientific content