In legal opinions, a
conclusion based on a
hypothetical set of
facts is dictum.
The hypothetical syllogism has two parts:
The Antecedent and the Consequent. Thus,
to argue against it you can deny the
antecedent or affirm the consequent.
• If the defendant was denied due
process, the conviction is invalid.
• The defendant was denied due process.
• Therefore, the conviction is invalid.
To deny the antecedent, just deny the conditional if. For example, argue “the denial
was harmless error.”
To affirm the consequent merely argue the defendant received due
Again though, the hypothetical syllogism can still be rhetorically
persuasive as Johnnie Cochran argued in the O.J. Simpson trial:
“If it doesn’t fit, you must acquit!”
Courts and Persuasion
Understanding fallacies protects us lawyers from ourselves. Plato
observed in Gorgias that
“The rhetorician [lawyer] need not know the whole truth …;
he only has to discover some way of persuading the ignorant
that he has more knowledge than those who know.”
If we understand fallacies, we can beat back the weaker legal argu-
ment with the judge. If done engagingly, it
also works with juries. There are hundreds
of responses to, “If it doesn’t fit, you must
acquit.” For example,
• Not fitting doesn’t mean he didn’t
• “It” is not the whole case and there
is plenty of other evidence to prove
• It really did fit and O.J. just gave the
only good acting job of his career.
But despite the best efforts of Langdell,
Holmes and others, law is not an exact sci-
ence, which Aristotle noted long ago:
“[I]t is evidently equally foolish to accept probable reasoning from
a mathematician and to demand from a rhetorician scientific proofs.”
Aristotle knew that law is a very human process, full of foibles and
Human subjectivity imbeds at the highest levels as Justice Robert H.
Jackson noted of the U.S. Supreme Court when he wrote,
“We are not final because we are infallible, but we are infallible
only because we are final.”
The outcome of our cases depends on much more than law or even
facts. As Holmes noted, the subjective experience of people—judges,
juries, lawyers, parties—plays at every turn.
Thus, knowing what this article attempts to present doesn’t guaran-
tee a win,
but it will give you an edge.
ARIZONA ATTORNEY JANUARY 2014 28
“Think Like A Lawyer”
3. Quoted in BLAIN ANDRUS, LAWYER: A BRIEF
YEAR HISTORY 102 (2009).
4. Quoted in DANIEL J. BOORS TIN, THE SEEKERS: THE
STORY OF MAN’S CONTINUING QUEST TO UNDERSTAND
5. Quoted in GOLDSTEIN & LIEBERMAN at 204. Justice Robert H. Jackson
gave the only
good performance of his
Indeed, Daffy may not be a duck because
the statement is not a true syllogism, but
a Hypothetical Syllogism starting with “If it
looks like a Duck.” But even if you take
out the conditional “if,” the statement also
shows the Fallacy of Accident—the hasty
Generalization, aka, “Jumping to
conclusions.” Daffy or Donald may
just be a duck hunter with a decoy
and whistle. Thus, the conclusion
may be a non sequitur because it
does not follow that “looking, quack-
ing and walking like a duck” is
always a duck.
1. More than one fallacy is often in the
same argument. Let’s take a duck!
• If it looks like a Duck
• Quacks like a duck
• Walks like a duck
• It must be a duck.
The Syllogism could be the following:
• All Ducks look, quack and walk like
• The defendant looks, quacks and
walks like a Duck.
• Ergo: Defendant is a duck
“But I am not
best efforts of
others, law is
not an exact