Have you ever read through the Declaration of Independence and thought to yourself, “What a clear presentation of reasoning. Why can’t our leaders today argue in such a straightforward way?” If you read the Declaration carefully, you can discern this pattern of reasoning:
If P then Q
P
Therefore Q.
This pattern of reasoning is called modus ponens, and the three parts of the Declaration can be understood in this way.
If any form of government becomes destructive of our unalienable rights of life, liberty, and the pursuit of happiness, then it is the right of the people to alter or to abolish it, and to institute new government.
The government of the king of Great Britain has shown itself to be destructive of these rights (as shown in a long list of grievances).
Therefore, these United Colonies are, and of right ought to be free and independent States.
One wishes that such clear reasoning would once again rule in the hearts and minds of our nation, its people and its rulers.
It seems to me that the pattern of reasoning called Modus Ponens can be thought of as being simply an arrangement in syllogistic form of the row of The Truth Table Of The Conditional which has the Truth Value called True assigned to the Antecedent (P) and to the Consequent (Q) and to the Conditional
(P->Q).
The way the Declaration is arranged in Modus Ponens form so as to form a logical Tautology …seems to me to be an excellent way to arrange things so as to give the appearance of clear reasoning; logical, correct, conclusive.
However, a quick look at The Truth Table Of The Conditional shows that this too, just like Modus Ponens, is a valid way to arrange a row in that Table:
If P then Q
P
Therefore NOT Q.
That is a perfectly logical pattern of reasoning. It is in fact Tautological. If the Conditional (P->Q) is True, and if P is True, then we can conclude that Q is NOT True …and that conclusion (“Therefore NOT Q”) is exactly as “logical” and “logical correct and reasonable” as the conclusion (“Therefore Q”) reached via Modus Ponens. However, no matter how perfectly logical the reasoning, it is NOT what I call “clear reasoning”!
However, such reasoning leads to this impeccably logical alternative conclusion to the Declaration:
Therefore it is NOT the right of the people to alter or abolish the government of the King of Great Britain, and it is NOT the right of the people to institute new government, and therefore these United Colonies are NOT, and of right ought NOT to be free and independent States.
Yet where is the fault in the logic? Is the reasoning really any less logical than Modus Ponens, from the perspective of The Truth Table Of The Conditional? If it isn’t logical then how can it be reasonable? If it isn’t reasonable then how can it be logical? Or isn’t it?
Yours puzzledly, Joe.