The argument from consistency

“Consistency, thou art a jewel!” – Unknown, though often attributed to Shakespeare

“The essence of Christian maturity is to have a high tolerance for ambiguity.” – Fred Smith

“Consistency is the hobgoblin of little minds.” – Ralph Waldo Emerson[i]

Emerson, Fred Smith, and Faux Shakespeare may all be on to something! “Consistency, thou art jewel” is an oft-quoted proverb used to good effect.  On the other hand, we often misunderstand the argument from inconsistency, or the argument for consistency.

Consistent is an adjective, and means “agreeing or accordant, not self-contradictory.” Consistency is the noun form, referring to such non-contradictory agreement or logical coherence of a thing (thought) and its parts. Logical inconsistency refers to making arguments that are not internally consistent. In logic or debate a consistent argument does not contain or lead to any logical contradiction.

An OUP blog post says:

“A theory is inconsistent if we can prove a contradiction using basic logic and the principles of that theory.”

The proprietor of “The Logic of Science” blog writes:

“[Consistent reasoning] is a fundamental requirement of the law of non-contradiction. It is, therefore, vital to make sure that your views are internally consistent, and pointing out inconsistent arguments can be an extremely powerful debate tool (it’s actually among my favorites).”

Sometimes it is a too-powerful debate tool. Over the years, in discussions of religious topics (which I cannot bring to mind at the moment) I have seen debaters throw down the gauntlet of “inconsistency,” thinking they then might confidently walk away the winner. Sometimes their opponents and their hearers misunderstand and submissively agree. However, they may have only given proof of inconsistency, and not proof of which inconsistent position is wrong or whether neither or both might be.

A simple but extravagant example can illustrate the point. A person may invoke an unsound argument for a conclusion, even though the conclusion itself is true. An inconsistent argument is proof of an inconsistent argument. It does not necessarily mean the conclusion is false. One might argue, Joe Biden is a Democrat because the ocean is blue. Donald Trump is a Republican because a strawberry is red.  These arguments are obviously non sequitur (Latin, “it does not follow”). The ocean is blue and strawberries are red, though those premises have little or nothing to do with the conclusion (the colors are related). Nevertheless, despite the hapless argumentation, the conclusions are true. Joe Biden is a Democrat. Donald Trump is a Republican

Be careful and be sure. Don’t immediately admit that inconsistency is proof of an error of your part and point – just proof of inconsistency. If your argument is inconsistent but your conclusion true, develop a consistent argument. If your conclusion is false, find the truth! (Proverbs 23:23; John 8:32) The truth shall make you free.

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[i] From the essay “Self-Reliance” by Ralph Waldo Emerson, a fuller quote is “A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines.”