Chapter 11 : Voter’s Paradox
Voter’s Paradox
Trilemma deduction
Syllogisms by Trilemma
11A. Voter’s Paradox
Consider
these three orders on the three forms:
6 < 1
< 0
0 < 6
< 1
1 < 0
< 6
The
minima on these orders cyclically distribute; so do the maxima. Taken together
they form a “troika”, a.k.a. a “voter’s paradox”, which is at the heart of
Kenneth Arrow’s Impossibility Theorem. These logic knots have a habit of
bollixing political systems. These tiny tangles give politics its notorious
perversity.
To
simplify presentation of the Troika, I introduce three fictional characters;
none other than the Three Stooges.
General
Moe rules the Scissors Party with an iron hand. His politics are fascistic; he
favors Lies over Truth over Imagination. He prefers monarchy, most preferably
if the monarch is himself.
Judge
Larry is senior theoretician for the Paper Party. His politics are legalistic:
he favors Truth over Imagination over Lies. He prefers to govern by consensus.
Mayor
Curly is lead singer for the Rock Party. His politics are populistic: he favors
Imagination over Lies over Truth. He prefers to govern by majority rule.
Moe: Imagination
< Truth < Lies
Larry: Lies
< Imagination < Truth
Curly:
Truth < Lies
< Imagination
Each
single Stooge has a consistent linear ranking of imagination, lies and truth;
but when you put them all together, something has got to go. Two-thirds of the
Stooges (namely, Moe and Larry) put truth above imagination; Larry and Curly
put imagination above lies; and Curly and Moe put lies above truth.
Moe Larry Curly
Lies
< Imagination? no yes yes
Truth
< Lies? yes no yes
Imagination
< Truth? yes yes no
This
gives us a Condorcet Election, or “Voter’s Paradox”:
Truth
< <
Imagination > Lies
- by
2/3 majority each; yet they all agree that the ranking is linear!
There
are several partial resolutions to this.
If we
appoint a single voter as tyrant (Moe, say) then we can decide this consistently;
but this is not a fair system.
If we
attempt to decide by consensus (as Larry suggests) then that is fair and
consistent; but we decide nothing, and that is a weak system.
If we
have faith in majority rule (as Curly professes) then we accept the non-linear
order, and the linearity of the order. This is fair and decisive, but it
is inconsistent.
Finally,
we can accept the non-linear ranking, and accept it as non-linear; this goes
with every 2/3 majority, but reverses a consensus; and that is perverse.
This
political knot is an instance of Arrow’s Impossibility Theorem, which
says that no voting system has all four of these virtues:
it is
fair: it gives all voters equal power
it is
decisive: it decides all questions posed to it
it is
logical: it does not believe contradictions
it is
responsive: it never defies a voter consensus.
In other
words, any government is at least one of:
cruel ;
weak ; absurd
; perverse.
Moe
prefers cruelty and lies, Larry prefers weakness and truth, and Curly prefers absurdity
and imagination; none of them want perversity and paradox, but of course
that is what they always get!
11B. Trilemma deduction
A
trilemma is a triple of propositions, any two of which can be true but not all
three. Any trilemma implies this deductive principle; from any two, derive the
negation of the third. For instance, this trilemma, the “disimplication glitch”:
A;
A
implies B;
Not
B.
implies these deductive rules:
From:
A; A implies B; deduce: B
From:
A implies B; Not B; deduce: not A
From:
not B; A; deduce: A does not imply B
So
modus ponens, modus tollens, and “anti-implication” are encoded by one
trilemma. A trilemma is an encapsuled near-absurdity; and near-absurdity is the
engine of deduction. Every deduction is a narrow escape, one trilemma wide.
And
for each trilemma, there’s a troika that generates it as a voter’s paradox. In
it, each of the three voters affirm two-thirds of the trilemma, and reject the
third.
In
this case:
Moe
says: A; A implies B; B
Larry
says: A implies B; Not B; not A
Curly
says: not B; A; A does not imply B
Take
the “strong or glitch”:
Not
A;
Not
B;
A or B.
It
implies these deductive rules:
From:
not A; not B; deduce: not A nor B
From:
not B; A or B; deduce: A
From:
A or B; not A; deduce: B
Here’s
a troika that generates it as a voter’s paradox:
Moe
says: not A; not B; not A nor B
Larry
says: not B; A or B; A
Curly
says: A or B; not A; B
Here’s
the “weak and glitch”:
A;
B;
not(A and B)
It
implies these deductive rules:
From:
A; B; deduce: A and B
From:
B; not(A and B); deduce: not(A)
This
is the “Failed Reductio” glitch:
A
implies B;
A
implies not B:
A.
It
implies these deductive rules:
From:
A implies B; A implies not B; deduce: not A
From:
A implies not B; A; deduce: A does not imply B
From:
A; A implies B; deduce: A does not imply not B
This
is the “disequality glitch”:
x
= y;
y
= z;
z ≠ x.
It
implies these deductive rules:
From:
x=y; y=z; deduce: z=x
From:
y=z; z≠x; deduce: x≠y
Here
is “Barbarism”:
All
A are B;
All
B are C;
Some
A are not C.
It
implies these deductive rules:
From:
All A are B; All B are C; deduce: All A are C
From:
All B are C; Some A are not C; deduce: Some A are not B
From:
Some A are not C; All A are B; deduce: Some B are not C
This is the “Disinduction
Trilemma”:
1 has property P;
For any n, P(n) implies
P(n+1);
For some N, not P(N).
It implies these deductive rules:
From: 1 has property P; For
any n, P(n) implies P(n+1);
Deduce: For all N, P(N).
From: For any n, P(n) implies
P(n+1); For some N, not P(N);
Deduce: 1
does not have property P.
From: For some N, not P(N); 1
has property P;
Deduce: For
some n, P(n) does not imply P(n+1).
This is the “Disintermediation
Trilemma”:
f(x) is real and continuous
on the interval [a,b];
f(x) does not equal zero
anywhere on [a,b];
f(a) and f(b) have different
signs.
It implies these deductive rules:
From:
f(x) is real and continuous
on the interval [a,b];
f(x) does not equal zero
anywhere on [a,b];
Deduce:
f(a) and f(b) have the same
sign.
From:
f(a) and f(b) have different
signs;
f(x) is real and continuous
on the interval [a,b];
Deduce:
f(x) does equal zero
somewhere on [a,b].
From:
f(x) does not equal zero
anywhere on [a,b];
f(a) and f(b) have different
signs.
Deduce:
f(x) is not both real and
continuous on the interval [a,b].
Here is the “First Cause
Trilemma”:
There is a first cause;
Every cause has a cause;
There are no causal
loops.
It
implies these deduction rules:
From: there is a first cause;
every cause has a cause; deduce:
there are causal loops.
From: every cause has a
cause; there are no causal loops; deduce:
there is no first cause.
From: there are no causal
loops; there is a first cause; deduce:
not every cause has a
cause.
The
trilemma can be written as:
There exists A, such that
for every B, A causes B.
For every A, there exists
B, such that B causes A.
There do not exist A and
B such that A causes B and B causes A.
This generalizes to any predicate R:
There exists x, such that
for every y, xRy;
For every x, there exists
y, such that yRx;
There do not exist x and
y such that xRy and yRx.
Call this the
“Loop Trilemma”. It’s a variant of the weak-and glitch.
When the predicate
is “explains”, you get the “Munchhausen Trilemma”:
Explanation is simple; there is a full explanation.
Explanation is complete; every explanation is
explained.
Explanation is not circular; no two explanations
explain each other.
Here’s
a “Set Loop Trilemma”
There exists an x, such
that for every y, yϵx;
For every x, there exists
a y, such that xϵy;
There does not exist an x
and a y such that xϵy and yϵx.
There’s
a universal set; every set’s an element; there are no set loops.
11C. Syllogisms by Trilemma
Consider
these modal identities:
Swap:
All
A are B = All not-B are not-A
No
A are B = No B are A
Some
A are B = Some B are A
Some
A are not B = Some not-B are not not-A
Negation:
Not
(all A are B) = Some A are not-B
Not(no
A are B) = Some A are B
Not(some
A are B) = No A are B
Not(some
A are not-B) = All A are B
Mode
Switch:
All
A are B = No A are not-B
No
A are B = All A are not-B
Some
A are B = Some A are not not-B
From
one side of an equation, deduce the other.
To these rules, add one more:
Some-All-None Trilemma: From
any two of;
Some
A are B
All
B are C
No
A are C
deduce
the negation of the third.
Modal
identities plus some-all-none trilemma yields the core of classical syllogism
theory. Adding existential import to ‘all’ yields the rest. For instance, modal identities, substitutions
and swap can transform the Some-All-None Trilemma to Barbarism in three steps
thus:
Some A are not not-B
All
not-C are not-B
All
A are not-C (by
modal identities)
Some
X are not Z
All Y are Z
All
X are Y (substitute
X=A, Y=not-C, Z = not-B)
All
X are Y
All Y are Z
Some
X are not Z (swap)
An
anti-syllogism is not a syllogism itself, but it’s always ready to explode into
three conflicting syllogisms. For instance; the Barbarism trilemma defies
classical logic; yet encodes three classical logic rules:
From: All X are Y, All Y are
Z, deduce all X are Z.
From: All Y are Z, some X are
not Z, deduce not all X are Y.
From: Some X are not Z, All X
are Y, deduce not all Y are Z.
The last two can be changed,
by substitutions and swaps, to:
From: Some X are Z, no Y are
Z, deduce some X are not Y.
From: Some X are Z, All X are
Y, deduce some Y are Z.
Exercise for the student:
Derive deduction rules and
troikas from these 24 trilemmas:
Some days are bliss;
All bliss is perfect;
No days are perfect.
All heroes are immortal;
Some men are heroes;
All men are mortal.
No philosophers are liars;
Some philosophers are Cretans;
All Cretans are liars.
Some flattery is stupid;
Stupidity is always boring;
Flattery is never boring.
Some good deeds are wise;
Only foolish deeds are punished;
No good deed goes unpunished.
Some angels read comic books;
Only aliens read comic books;
No aliens are angels.
Only you can prevent forest fires;
Smokey the Bear can prevent forest fires;
You are not Smokey the Bear.
All Scots are canny;
All ghosts are uncanny;
Some Scots are ghosts.
Dragons are wise;
Dragons are brutal;
Dragons are not both wise and brutal.
I am a bum;
All bums are crooks;
I am not a crook.
I love Alice;
I do not love Bob;
I love Alice and Bob equally.
Bob is not a genius;
Bob is not an idiot;
Bob is a genius or an idiot.
If Alice fell down a rabbit hole, then
I’ll be a monkey’s uncle;
If Alice did not fall down a rabbit
hole, then I’ll be a monkey’s uncle;
I will not be a monkey’s uncle.
There are more saints than sages;
There are more sages than heroes;
There are more heroes than saints.
A crook is better than a fool;
A fool is better than a wimp;
A wimp is better than a crook.
The food is fast;
The food is cheap;
The food is good.
The pundit is honest;
The pundit is intelligent;
The pundit is partisan.
An attorney should investigate zealously;
An attorney should keep client’s secrets;
An attorney should report perjury.
Superman can fly;
Clark Kent can’t fly;
Clark Kent is Superman.
Some frogs are princes;
Some frogs are not princes;
All frogs are equally princes.
All lions are fierce;
Only coffee-drinkers are fierce;
Not all lions drink coffee.
No ducks waltz;
All officers waltz;
Some officers are ducks.
Time is unbounded;
Time is linear;
Time is finite.
There is a final effect;
All effects have effects;
Effectuation does not loop.
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