Logic
is a very powerful tool that debaters can use
to find the flaws in and destroy the other
side's case. Let's begin by making a very
simple, yet incredibly important,
observation: Whenever someone says something,
we have to support the opposite in order to
argue with that person. Likewise, we do not
have to disagree with everything the other
person says, as long as we still support an
opposite view.
If
someone claims that two statements A and B
are both true, then it suffices to show that
one of these two statements is false. In
doing so, we will have shown that not both of
them are true, therefore disproving what that
person had said. Hence, any of "A
is false, but B is true",
"B is false, but A is
true", or "both
A and B are false" will
fulfil their role in opposing what had been
initially said.
Now,
lets clarify what has just been said by way
of an example. Imagine that Alice,
also known as the proposer,
currently supports funding a new economic
plan, a move to subsidise farm growth by
reducing the current budget allocation for
industrial subsidies. Alice's proposal consists
of two parts, reducing industrial subsidies,
and increasing farm subsidies. Bob
on the other side, also known as the spoiler,
has a tradition of opposing everything the
proposer says. He's considering the three
different approaches that would counter her
case:
One
would be to claim that "while
increasing farm subsidies
would be a good thing
overall, we cannot afford
reducing industrial subsidies".
Another
option would be that "while
industry is indeed doing well
and doesn't need so many
subsidies any more,
subsidising farms would do no
good to help them grow".
Finally,
he could say that "we
cannot afford cutting back on
our vital industrial
subsidies, moreover, the farm
sector would not be benefited
by those funds".
Being
smart, as well as blessed with the gift to
always make the best choice, Bob decides not
to waste much time on an approach that is
hard to prove. Instead, he allocates more of
his time towards the easier approach, which
serves his cause of winning the argument
equally as well. Ideally, however, he'll be
able to support III.
That is, try to prove both that "we
cannot afford cutting back on our vital
industrial subsidies"
and that "the farm sector
would not be benefited by those funds".
Even if the proposer later destroys one of
his proofs, Bob's third
approach will revert to one of the two other
approaches, still disproving Alice's case.
Now
lets consider another case, where someone
claims that at least one of two statements,
either A or B, is true. That person, would be
at an advantage, whence only needing to prove
one of: "even though A
is false, B is true",
"even though B is false,
A is true", or
"both A and B are true".
To prove that person wrong, we'd have to show
that all of these statements are false, hence
showing that neither of them can be true.
An
example for this case is much simpler: Alice is
proposing two alternatives to capital
punishment; she thinks it would be better if
all such criminals were either imprisoned for
life, or lobotomised. In doing so, our
beloved proposer doesn't want to limit
herself in arguing one of these alternatives.
Instead, she argues that at least one of them
would be viable. Alice will need to prove one
of: "while you may
not consider lobotomy to be a good
alternative to capital punishment, you can't
say the same thing about life imprisonment",
"even if you don't think
that capital punishment could be viably
substituted by life imprisonment, you could
substitute it with lobotomy",
or "both life
imprisonment and lobotomy are good
alternatives to capital punishment".
Ideally, she'll try to prove the third
option, by supporting both alternatives. If
Bob later manages to disprove one of them,
the proposer's third
option will revert to one of the other two
that still supports the untouched
alternative. The spoiler pauses for a moment
to think his options... but there aren't any!
He has to argue against both life
imprisonment and lobotomy, as failing to
disprove one would not suffice to counter
Alice's argument.
"The
opposite of both A and B, is either
the opposite of A or the opposite of
B" (also written as: "NOT (A and B) =
(NOT A) or (NOT B)")
"The
opposite of either A or B, is both
the opposite of A and the opposite of
B" (also written as: "NOT (A or B) =
(NOT A) and (NOT B)")
These
two symmetric observations pretty much sum up
what has been said so far. They constitute
what is known as Demorgan's Theorem. As you
might have noticed, combining statements with
an "or"
seems to benefit the proposer,
Alice.
Combining statements with an "and"
on the other hand, seems to benefit Bob,
the spoiler.
Such cases are referred to in relevant
bibliography as "original"
or "land"
cases respectively.
Ok,
now that you know these things, you need to
learn how to use them in debates. One obvious
use, if you're an opening government team, is
to give an original
definition. That way you'll ensure that
you're proposing an easy to defend case,
giving your side of the house a competitive
advantage. If you're an opposition team on
the other hand, make sure you take advantage
of a land
proposition when you see one.
Another
very neat trick you can use to disprove
virtually every argument, is induction.
You can reduce a case, into easier to manage
smaller statements, joined by and's
and or's.
After doing that, take each of these
statements by itself. Forget for a while that
it was part of a larger case, treating it as
a separate entity. Now think of how you could
split this statement into sub-statements. If
it can't happen without some other things
happening at the same time, then all of these
are actually joined by and's.
If it can happen in various different ways,
then these are joined by or's.
Continue splitting all statements into
sub-statements and all of these into even
smaller statements. What you'll eventually
end up with, are the building
blocks of the
proposed case. If these atoms
of argumentation contradict with each other,
then the way to destroy their union lies
through exploiting that contradiction. Even
with no contradiction apparent, however,
these particles
are bound to contain some assertions. Try to
bring the other side in a position where
they'd have to prove these assertions. If
your inductive descent
was deep enough, it will be next to
impossible for the other side to back them
up.
