Toulmin’s Uses of Argument

Stephen E. Toulmin The Uses of Argument (Updated Edition) CUP 2003 (Original 1958).

This is well regarded by many, hence the new edition. Toulmin thinks of claims as being justified if there are warranted arguments from specified data. Warrants apply to ‘fields’. These filed-dependant warrants may either be general to the field, or requiring backing for their application. Justified claims may be treated as if they were true.

Toulmin recognises the claim of logic and mathematics to a superior kind of warrant, but points out that these do not bear directly on the ‘real world’. He is (rightly) scathing about those who seek to (mis) apply such logic and mathematics outside their proper sphere.

A logical difficulty is that the use of warrants would seem to require some sort of argumentation, which would depend on warrants, and so on in indefinite regress. Toulmin supposes that this process comes to an a bottom with some definite field-dependent warrant that is held to be absolutely true.

Toulmin considers a range of alternative views, dismissing most of them with informal yet persuasive arguments. The exception is a view resembling Russell’s Theory of Knowledge. He is very rude about it, but I can see no actual argument.

I find Toulmin’s notions of claims, data, warrants and backing helpful. But logically I agree with Russell, that any attempt to ground out a field in absolute warrants will turn that field into dogma. Thus where Toulmin claims that some claims can certainly be justified, I would only go so far as to say that claims can be justified relative to a field. For example, a claim about economics will only be justified according to some dogmatic field, such as neo-classical economics. In effect, Toulmin supposes that we will have unquestionable fields, such as neo-classical economics, so we can always treat a justified neo-classical claim as if it were a justified claim in economics. (Or equivalently, treat economics as if it were neo-classical.) But I agree with Russell (and Keynes) that we should always entertain some doubt about this, no matter how little.

We could reconcile Toulmin with Russell et al by  supposing that Toulmin is concerned with argumentation within the field, whereas Russell et al also consider arguments about the field. This distinction mirrors Whitehead. For example, it seems to me that most fields rely on some form of induction. This may be the best one can do, and essential to having a productive field, but – as Russell et al point out – is not absolutely reliable.

Toulmin notes the importance of distinctions. If a field ignores certain distinctions then any claims will only be justified to the extent that the field is justified in ignoring the distinctions. Toulmin also has some discussion of the need for complete relevant data. I am not clear how, in practice, one would warrant this, for example if some distinctions have not been made. So maybe I should regard a claim as warranted relative to distinctions made and the assumptions that informed the selection of data, backing and warrants.

Toulmin also has an interesting concept of probability, but my only comment here is that it, too, would seem to merit reviewing with the work of Russell et al in mind. Overall, Toulmin’s approach seems like a refinement of common-sense applicable to mono-cultural deliberative reasoning to a definitive conclusion in routine, stable, situations. My own experience is that claims often need adjusting, or caveating, to be justifiable.


[Nothing] in what follows pretends to be final, and I shall have fulfilled my purpose if the results are found suggestive.

I Fields of Argument and Modals

The words of some men are trusted simply on account of their reputation form caution, judgment and veracity. But this does not mean that their right to our confidence cannot arise in the case of all their assertions: only, that we are confident that any claim they make weightily and seriously will in fact prove to be well-founded, to have a sound case behind it, to deserve – have a right to – our attention on its merits.

Note a distinction. It may be that we are confident that someone will only make claims that are justified according to their own warrants, or that they will make claims that we would find warranted. Where understanding of an area differs, trusted people will presumably restrict their claims so that they are warranted for both themselves and their intended audience. Toulmin does not discuss this, and in any case assumes some common underpinning of warrants.

In order for a suggestion to be a ‘possibility’ in any context … it must have ‘what it takes’ in order to be entitled to genuine consideration in that context. To say, in any field, ‘Such-and-such is a possible answer to our question’, is to say that, bearing in mind the nature of the problem concerned, such-and-such answer deserves to be considered. This much of the meaning of the term ‘possible’ is field invariant. The criteria of possibility, on the other hand, are field-dependent … .

For example ‘yes’ seems not to have been a possible answer to ‘might the economy crash within the next 5 years’ in 2005, if the field was neoclassical economics (or economics viewed neo-classically).

III The Layout of Arguments

[The] applicability of a particular warrant is one question: the result we shall get from applying the warrant is another matter, and in asking about the correctness of the result we may have to enquire into both things independently.

Toulmin introduces a  graphical representation:

Data (D)  ——> So Claim (C) subject to qualifier (Q)
……..……..…..|                                       |
……..……..Since                              Unless
……..Warrant (W)                  Rebuttal (R)
……..On account of
……..Backing (B)

Some warrants must be accepted provisionally without challenge, if argument is open to us in the field in question: we should not even know what sort of data were of the slightest relevance to a conclusion, if we had not at least a provisional idea of the warrants acceptable in the situation confronting us. The existence of considerations such as would establish the acceptability of the most reliable warrants is something we are entitled to take for granted.

He gives as example:

D (Petersen is a Swede) —> So Q (almost certainly) C (Petersen is not a Roman Catholic)
……………………….              |
Since, W (A Swede can be taken to be  almost certainly not a Roman Catholic)

Because,  B  (The proportion of Roman  Catholic Swedes is less than 2%)

This seems doubtful to me, unless – for example – Petersen was selected at random from all Swedes. But later Toulmin opines:

If we imagine a to challenge [the above] argument, and to demand further backing to show its validity, his request will be no more intelligible than [if the backing were that no Swedes were Roman Catholic]. … If he fails to see the force of the argument, there is little more we can do for him … [The] ability to follow such arguments is, surely, one of the basic rational competences.

Before this, he had noted:

[The] acceptability of a novel warrant is made clear by applying it successively in a number of cases in which both ‘data’ and ‘conclusion’ have been independently verified.

A regular prediction, made in accordance with the standard equations of stellar dynamics, is in this sense an unquestionable deduction.

It seems to me that for Toulmin the ‘basic rational competence’ , above, provides a kind of universal warrant. Clearly, one could ‘almost certainly’ in the way Toulmin advocates, but that would seem to leave a gap for a term with quite different meaning.

Toulmin goes on:

The ability to follow simple predictive arguments, whose warrants have been backed by sufficiently wide and relevant experience, may just have to be recognized as another simple rational skill, which most men possess but which is lacking defectives … .

If we are prepared to acknowledge Newtonian mechanics is sufficiently well established for the purpose of the problem at hand, then we must accept [a particular conclusion] as following necessarily from our … data.

IV Working Logic and Idealised Logic

Two people who accept common procedures for testing warrants in any field can begin comparing the merits of arguments in that field: only where this condition is lacking , so that they have no common ground on which to argue, will rational assessment no longer be open to them.


[A] radical re-ordering of logical theory is needed in order to bring it more nearly into line with critical practice … .

If the same as has long been done for legal arguments ere done for arguments of other types, logic would make great strides forward.

Accepting the need to begin by collecting for study the actual forms of argument current in any field, our starting point will be confessedly empirical … . … We must study the ways of arguing which have established themselves in any sphere…. knowing that they may be superseded, but only as the results of a revolutionary advance in our methods of thought. In some cases … the fact that they have established themselves in practice may be enough for us.

My comments

Fields seem to be ‘owned’ by groups resembling medieval guilds, and not open to outside criticism. While this possibly is how many fields operate, I do not think it is how they ‘should’.

Dave Marsay

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