NOTE: I’ve been tolerant of the back-and-forth concerning the Rittenhouse trial, but in my opinion, that has run it’s course. So, a new post is in order, as a ‘breath of fresh air,’ as it were.
Today’s Post is brought to us again by our own The Real Guy Faux.
In the last installment, I went over the Laws of Thought and rules of inference that govern propositions of the If-A-then-B sort.
In this installment, I thought I’d mention the rhetoric-versus-eristic battle again.
Aristotle felt that rhetoric was the art of persuasion that didn’t clobber someone over the head, but let them draw their own inferences, while of course the speaker/writer was loading the question, if you will.
One way of accomplishing this was through the use of an “enthymeme.” An enthymeme is an incomplete argument that is not necessarily WRONG thereby, it’s just left a step out.
One of the most common sorts of argument is the categorical syllogism,
“[All/some/none] of F’s are G’s; [all/some/none] of G’s are H’s; therefore [all/some/none] of F’s are H’s.” There are rules for those that I may get into another time, but suffice it to say that the one I’m about to offer as an example is valid:
“All Greeks are mortals.
Socrates is a Greek.
So, Socrates is a mortal.”
An enthymematic treatment of that syllogism is:
“All Greeks are mortals.
So, Socrates is a mortal.”
It has the virtue of being true, but yet your recognition of its truth depends on your knowing Socrates is Greek and plugging in (some might call it “smuggling in”) that fact as the minor premise (the second of the three in the categorical syllogism illustration). Otherwise, strictly speaking, you’ve jumped to a conclusion.
Now, only the biggest troll of an eristic type would quibble over THAT particular enthymeme, and the syllogism it’s “shorthand” for, by saying, “Show your work, Ari!”. But many other enthymemes might derive from invalid syllogisms, and the eristics would be well within their rights to say, “Nope, you’re committing [fallacy]…” and they can always also say that while the full syllogism might be valid if everything stated was hunky-dory, and that the enthymeme was a fair abbreviation of it, nevertheless what’s being said is unsound because it’s based on false premises (from which any conclusion can be drawn). Example.
“All Frenchmen drink wine.
All wine drinkers are winos.
So, all Frenchmen are winos.”
Aside from the fact that it’s an offensive stereotype both of the French and of wine drinkers in general, it is factually untrue. It’s a VALID argument, at any rate in its construction, but not a SOUND one. Its enthymeme, either the major premise (the top one) or else the minor premise (the second one), plus the conclusion, is likewise unsound.
And, altogether too many of the arguments you hear, in favor of, or opposed to, some sort of policy positions are unsound because they rest on false premises. Now, if the argument is an enthymeme, it invites people to supply the missing premise, which may be false (but based on something the proponent has already said that they’ve agreed with, perhaps inadvisedly). In addition, the major premise may be false from the git-go. In other words, the whole argument may be a crock, but the conclusion “follows” and is not some violation of the very form of the argument structure. It’s not just categorical syllogisms where this happens, either:
“The rich don’t pay enough in taxes [matter of opinion].
My bill addresses that injustice [loaded language].
Therefore, pass my bill so that we can get the rich to pay their fair share [loaded language]”
Now, it might be that as a result of this politician’s appeal, the bill will pass, because the other legislators agree with the premises and conclusion. But does the conclusion follow from the premises? It might, from a strict validity standpoint, the modus ponens argument of “If you pass a bill taxing the rich, then you make them pay more in taxes. You do pass the bill. So, the rich will pay more in taxes.” But then an eristic can always come along and say, “Define ‘rich,’ and define ‘more in taxes’,” and of course the devil will be in the details,
Aristotle said that effective oratory a rhetorician will employ takes into account the question of whether what the speaker says is credible as well as whether it’s getting the listeners’ attention. Of course, he wasn’t advocating that a speaker out-and-out lie, but what he was saying wasn’t so much a moral as a practical consideration, i.e., “Am I expressing this thought in a way that invites belief in what I’m saying?”, and of course, if your intent is to hoodwink the audience, you want to make the lie plausible, not outlandish. So, if you ask them to “do the math” and add their own premises, then your premises had better “sound right” to them in the first place. If your premises do NOT, even if what you’re saying is the actual state of affairs though it might sound to some as outlandish (see: Galileo, e.g.) if your premises are not believed, they can’t be acted upon. It might be that the audience is prejudiced in some way and wouldn’t believe you even if you said “nighttime is dark.” You might have to engage them in a challenge, a “thought experiment”: “OK, you don’t believe ME, but let’s just say, arguendo, that nighttime is dark, and let’s see where that leads…”
And that’s where modal logic, to be discussed another time, comes in.
