The structure of logic in argumentation
Organizing an Argument Logically
• One of, if not the most important aspects of argument in an academic environment
is logical reasoning, at least according to Aristotle. Since he is the father of
rhetorical theory, it stands to reason that after more than 2000 years of holding this
position, there may be something to his claim—
Logos matters most.
• Stephen Toulmin, a modern theorist, developed a simple structure for how to
identify and organize the logic in an argument, both explicit and implicit elements,
when either composing or analyzing. This model is what we will use organize our
ideas on our research topic+thesis to ensure our reasoning is both valid and sound.
The Basics: Three Primary Elements
• Just like with logical syllogisms, there are three primary elements in the Toulmin
model. Those three parts of deductive reasoning also correspond directly to the
three dominant parts of Toulmin’s model.
• Warrant (general assumption) Major Premise (general category)
• Grounds (specific evidence) Minor Premise (illustrative case w/in category)
• Claim (deduction/argument) Conclusion (inference drawn from premises)
Warrant: How to read the evidence
• A warrant is usually an assumption, a value belief that is commonly held by both the author and the
target audience to be true.
• Many times, the warrant is something presumed to be self-evident, so much so that it may seem too
obvious to even give attention to when analyzing someone else’s argument or when formulating one’s
own. (We all know what they say about what happens when you assume…)
• Warrants can often represent the biggest problem when trying to discover the most factual and
evidence-based conclusion on controversial topics. We become blind to them.
• However, the warrant is often, in fact, the major point of disagreement between those engaged in
debate or discourse, and thus what prevents opponents from arriving at a shared understanding of
both sides of the case—what has truth value and what is merely a personal matter of taste or
enculturation. If both debaters start with differing understandings of the underlying assumptions on a
topic, neither will be able to see how the other arrived at his or her conclusion.
Warrant: How to read the evidence
• The warrant is like the general category of a major premise in a syllogism. It is
the definition of the general category that determines how the specific case or
evidence that follows should be understood. This tells the reader how to understand
the minor premise it is paired with—it enframes the way we see the evidence.
• Take the most recognizable syllogism in western culture as an example:
(since) All men are mortal + (and/because) Socrates is a man = (ergo/thus/then) Socrates must be mortal.
• The warrant is the first premise or proposition: ALL men are mortal (by definition)
Venn Diagrams: Category Membership
The warrant is usually a larger (hence more general) category classification than a
ground (a single instance that falls within the warrant’s sphere).
All mortal things is the largest category. Within that taxonomic sphere, more
things than just human beings exist (animals, reptiles, bacteria, vegetation, insects,
arachnids, etc.). Anything that lives and dies is by definition mortal. However, the
whole (all) of mankind is one category within that larger classification. With all
contained therein, the categories are like nesting dolls.
Inside the sphere of mortal human beings, there are numerous examples of
individuals who could be used to illustrate that membership in one group
necessitates membership to the larger group.
In the syllogism, however, the example given is an individual who seems larger-
than-life. Thus, if he can be labeled man(kind), he also has to be mortal, so it
stands to reason that he is as human and mortal as the rest of us.
Putting it Together: Warrant + Grounds = Claim
• Here’s how the logic of this three part system works (written out):
• (warrant) Keeping in mind that the warrant is the categorical assumption (cultural/social
norms define human beings as organisms that die: mortal),
• (ground) when we pair that concept with a specific, representative example that fits
within its category (an actual, historical person: Socrates),
• (claim) we can then logically deduce that based on the example’s membership within
the larger category (if true), whatever applies to the category as a whole also applies to
the sample specimen/object (our example is mortal—he can’t live forever; he is just a man).
The Basic Equation: W+G=C
• If you add the first premise to the second, you should come to a logical conclusion. If both
premises are high in truth value, the conclusion should likewise carry high truth value.
• Sound premises should lead to sound conclusions (if the logic is good)
• Correct deduction (Major/W + Minor/G) will result in valid (logically accurate) conclusions
• Just like in math, incorrectly combining the two variables in the equation will result in a false product
• This is why knowing what you are dealing with (defining terms and functions) matters in argumentation
• The warrant tells you how to understand/read the evidence to reach the claim.
• Just like with syllogisms: Major + Minor = Conclusion
• Toulmin runs parallel: Warrant + Grounds = Claim
Grounds: Representative Evidence
Grounds (the minor premise) should only ever rely on the kind of example or evidence that
will best illustrate (exemplify/an exemplar of) the point you are making. What that means is
that you cannot use just any old instance to make your case. Some examples are better than
others, and some examples can set your argument up for failure.
Poor examples include those instances that are anomalies—outliers, mutations, abnormal
instances, unpredictable cases, rarities. The exception does not prove the rule, so while many
novice debaters often try to use a single case to refute your position, one instance of
deviation from your claim is not enough to invalidate it, unless you have set up your claim as
an all-or-none fallacy. This is why limitations (qualifiers) matter.
Representative Grounds: “Normal”
Using abnormal (non-predicable) examples represents a
kind of hasty generalization, where an entire population is
falsely described by the behavior of a single, non-
This would be like using Einstein to define an average
(normal) IQ or Bill Gates to define financial success. They
are unusual circumstances—well below a statistically
significant number. Not many have/will ever follow suit.
As a general rule, if fewer than 51% of a population
(category membership) is not likely to do the same thing as
the example used, the example is grossly fallacious; it
misrepresents its categorical population trends.
Rebuttal: Refuting the Opposition
• Usually in the invention and arrangement stages of writing, you have to give serious
consideration to both sides of the argument in order to have a complete picture of the
issue. That means weighing out both sides of the case, not just focusing narrowly on
your own position.
• Failing to keep the main arguments and evidence of your opposition will set you up for
failure by limiting your focus to only those supporting claims and evidence you want to hear.
This kind of approach is like group-think—dangerous. Poor decisions are made this way.
• A strong argument is well-informed, balanced, and considerate. A fair and thus scholarly
rhetor keeps in mind the idea that there are at least two equally legitimate positions on a
topic, both of which deserving to be heard. He or she is also interested in coming to a
sound conclusion (main claim) based on hard evidence (logos), an outcome that, like justice, is
supposed to be an unbiased evaluation—a weighing out of the facts.
Rebuttal: Refuting the Opposition
• Just like in a game of chess or a court case, to be successful in argumentation, you have to
keep in mind who you are playing against. The more you can predict the moves of your
opponent, the better you will be able to defend your position.
• The language of argumentation is largely combative in nature—the metaphor of war: e.g.
defending one’s position, formulating an attack, taking an offensive strategy, going up
against an opponent, taking sides. However, in academic argument, your goal should not
be to win at all costs, but to present an honest, evidence-driven, and logical case.
• Think of academic argument as a kind of artful game where truth value (not capital-T truth)
is tested—examined, evaluated, discovered, publicly performed. For a good game, you want
a fairly matched opponent, one who is as invested as you, as prepared, and equal in
Rebuttal: Refuting the Opposition
• Even with an equitable perspective in mind, it makes sense to try and consider what your opposition is likely to
do—his best moves. Knowing his strong and weak points should help you to organize your defenses and strategize
your offensive moves. In this way, your goal should be to prepare your position for active engagement. Successful
military tacticians, lawyers, gamers, athletes, and rhetoricians all know that the best defense is a good offense.
• So too, knowing what your opponent’s case is built around will help to guide what you address in your own
argument. If you are going toe-to-toe with someone who intends to debate the most recent evidence on global
warming, then, it only makes sense that it would be a waste of time to argue using 10-20-year old sources and
evidence; you will be debating totally different aspects of the topic. In such a situation, there can be no conclusion as
there is no argument, just two unrelated points on a subject—one historical, one contemporary. This is like trying to
play checkers against chess on the same board. You have to know what you are playing for there to be an outcome.
• To know what you need to address, then, what kind of evidence you should focus on, you have to read what has been
said, find problems in the opposition’s position, and then focus your attack there, where it’s relevant, worth
pursuing, and most importantly, actually arguable. To break through a tough defense, it helps to know where it’s weak.
Limitations & Qualifiers
• A common problem that can severely weaken a position is over estimating and over generalizing
your point. This is usually done by relying on erroneous or excessive descriptors—all, none, no,
never, always, every, etc. Any case where an all-or-none statement appears, it negates itself
inherently as a fallacy; the debate is over, and you lost. This is not a good strategy.
• Such qualifiers misrepresent a position by making absolutist claims, where in reality, there is no
such thing as an absolute category without any variation, mutation, outlier, or potential deviation.
This principle is kind of like “the only rule is there are no rules;” trying to rebel against it or reject
it on the grounds of incidental irony or absurdity will simply get you caught up in the paradox.
• Instead of trying to make overly presumptive claims about what you are arguing, the more honest,
specific, and up-front you are about your position, the more sound and credible it will seem.
Rather than trying to make statements about absolute truths, argument in academy is about
provable and thus probable—we rarely have all the evidence before we try a case, so we have to
admit to what we are really working with.
Limitations & Qualifiers
In general, it is best to be as specific as possible when making declarative claims (main or supporting). What that means is that you have to limit
your arguments and statements to only those points, explanations, definitions, interpretations, and declarations that can be proven—empirically.
If you cannot measure it, bring it for show and tell, put it on a scale, poke it, touch it, hold it, or physically experience it, it is not admissible in
As such, anything you cannot prove should not be said. Likewise, you have to make sure that you are as clear as possible in how you state your
position. You are rarely arguing anagogically abstract truths like what is truth, or beauty, or goodness; those are debates for philosophers, not
short essays in English or history or criminology. In reality, academic or professional arguments are more likely to be specific and in response to a
single problem, warranting a simple, straightforward solution, not a solution that is supposed to then represent every similar case universally.
Instead of trying to argue that the drinking age should be raised (vague, general), claim that your position is to change the age of alcohol
consumption to reflect the age of cognitive maturity by raising it to 25 from 21, based on the January 5th issue of Psychology Today’s article on
human brain development and problem solving. The second statement is debatable, clear, specific, and in response to an existing, findable, and
credible source. The first is a general concept—the topos, not the thesis. The more qualified your claim, the easier it is to focus, to argue—
to prove it.
Backing it Up: Prove It
• Warrants are often general assumptions, meaning that a large number of people will hold it
to be (in a way) self-evident. Warrants that Americans often think little about might include
all persons being created equal, the right to pursuing life, liberty, and happiness, and the right
to free speech or peaceful protest.
• However, in many places in the world, these would not be assumed truisms, much less self-
evident rights protected by rule of law. Instead, they would have to be backed up to hold up
against cultural relativism in a court of law. By offering additional evidence, like excerpts
from essays by John Locke and Thomas Paine on the rights and liberties of man(kind), not
only do you ground those warrants historically, but you offer sources that have more
credibility than someone new to the debate (you) and thereby enhance your ethos—the
strength of your argument’s believability. This is what is called backing.
Backing: The Foundation for the Warrant
• Never assume. In argument, assuming sets you up for an attack you cannot defend. Instead,
any kind of presumption you have should be backed up explicitly so there is no room for
ambiguity or misunderstanding.
• Backing is important for clarity, which matters in a good debate. You want to bring a clear,
focused, logical, and well-informed case against an equally organized, informed, and
• This often means that to back up your position, you have to define your terms, offer more
evidence that sometimes seems necessary just to cover your bases, and explain past the point
where you think you need to because you are not just trying to show what you know but to
actually convince, teach, and move your opponents to take your side. You cannot do that if
you take things for granted or build your case on a weak foundation. Back everything up.
In Short: Toulmin’s Model
• Warrant (general value)
• Grounds (specific evidence)
• Claim (arguable point)
• Backing (support for warrant)
• Qualifier (limitation of premise)
• Refutation (rebuttal of opposition)
• If you can clearly identify and
explicitly state each of these six
elements of logical argumentation,
you will be on the path to a strong,
rational, and thus provable argument.
• Once you have this part of the
invention process down, you can
move on to arranging and drafting.