Rhetoric, part 2–Tropes and Schemes (99)
Published by Dave March 1st, 2008 in podcast, howard s., daveRhetoric, part 2–Tropes and Schemes: Howard Shepherd and Dave Shepherd continue their discussion of rhetoric by exploring tropes, schemes, and Lincoln’s Gettysburg Address.
Grimace from the Word Nerds Forum corrects us on our example of a syllogism. (2:31)
Content versus style; tropes and schemes defined; and some examples of tropes. (Note: despite what Dave says in this segment, Edward P. J. Corbett’s book Classical Rhetoric for the Modern Student is only available in hardback.) (4:46)
Music bumper from “Under the Stairs” by Sonic Deviant. (12:18)
Schemes: a transference of order; shifts of structure in language (12:54)
Song: “The Battle Hymn of the Republic” performed by The United States Air Force Band and the Singing Sergeants (29:15)
Rude word of the week: blowhard (34:11)
Music bumper from “Nada” by Jaime Beauchamp. (37:13)
Next time we will examine some examples of rhetoric in public speech. (37:52)
Dave reads Abraham Lincoln’s Gettysburg Address. (38:39)
Music courtesy of The Podsafe Music Network and the United States Air Force Band
Theme music by Kick the Cat
time: 42:48
size: 39.2 Mb
rating: PG (Howard gives one slightly suggestive example of litotes.)
Howard, when discussing the quote “Friends, Romans, Countrymen, lend me your ears” from Shakespeare’s “Julius Caesar,” mis-attributes the line. The funeral oration is given by Marc Antony, not Brutus.
As Homer Simpson would say: “Doh!”
Tyler is absolutely right. This was an example of my being overly fastidious; I mixed up the two speeches of Brutus and Marc Antony.
Brutus’s speech begin with “Be patient till the last.” He then goes on to give a speech as logically compelling and as rhetorically flat as a Jimmy Carter speech on energy conservation.
It is Marc Antony who is the successful rhetorician–in the negative sense of the term. Throughout his speech, Antony repeats the refrain “Brutus is an honorable man”==but each time, he juxtaposes it with a counter-example of Julius Caesar’s life that makes the phrase more and more bitterly ironic. At the end, he has whipped the Roman rabble into a frenzy.
Thanks, Tyler, for setting me straight.
I am a bit confused. Weren’t you expecting this to be a two part series?
Now it is going to the three, but I decided to review it already - I couldn’t wait.
http://anneisaman.blogspot.com/2008/03/rethorics-series-by-word-nerds.html
A
Fortunately logic IS my strong suit - I make my living on this particular area of logic.
In the logic world, the rule is called Modus Ponens, and it works out to
If A implies B and B implies C, then A implies C
the trick is that you need to keep order and B needs to always be true if A is true, as well as C needs to be always true when A is true.
The Socrates example is
If all men are mortal (note this is B implies C)
and Socrates is a man (this is A implies B)
then Socrates is mortal.
If your second proposition is Socrates is mortal, you have A implies C, and you cannot infer that A implies B - you don’t have the logical chain.
I knew that Masters in AI would come in handy some day.
Sorry. I just realized I made two typos.
fourth paragraph should be
the trick is that you need to keep order and B needs to always be true if A is true, as well as C needs to be always true when B is true.
And further down I should add that
then Socrates is mortal. is (A implies B)
It works in mathematics, and other logic as well as rhetoric, and is the basis for rule chaining in Expert Systems.
All right! My friend Julie has almost literally drawn me a picture, for which I am very grateful! Your penultimate sentence is the key to my understanding. If you say A implies C, then you’ve skipped a step.
Thanks, Julie!
Sorry to disagree, but I’m not so sure that’s correct.
A statement of the form:-
A implies B
B implies C
Therefore A implies C
…is indeed a syllogism, but it doesn’t apply to the Socrates example, and doesn’t have anything to do with modus ponens. It is in fact a hypothetical syllogism, whereas the Socrates example is a categorical syllogism, or more specifically a universal syllogism (there is also something called a disjunctive syllogism, but I won’t go into that).
The universal syllogism (or any categorical syllogism) often isn’t considered a discrete law in modern logic because it is in fact a combination of two existing rules (and therefore requires an intermediate step): the rule of universal instantiation (that is: what is true of every individual thing must be true of any one thing) and modus ponendo ponens (more commonly just called modus ponens), which says:-
A implies B
A
Therefore B
The full universal syllogism, therefore, would look like:-
For-all x in set S (A(x) implies B(x))
Therefore A(c) implies B(c) when c is an element of S
A(c) implies B(c)
A(c)
Therefore B(c)
Or in the Socrates example:-
(Begin universal instantiation)
For all things, if that thing is a man, then that thing is mortal
Therefore if Socrates is a man, then Socrates is mortal
(Begin modus ponens)
If Socrates is a man, then Socrates is mortal
Socrates is a man
Therefore Socrates is mortal.
Because we are used to categorical syllogisms, we tend to take “If Socrates is a man, then Socrates is mortal” as implicit, but in modern logic, which tends to be concerned with what computers can understand, it’s not admissible to skip a step like that, and “If Socrates is a man, then Socrates is mortal” is what’s known as a ‘lemma’: a minor conclusion that needs to be proven (even if only in one step in this case) in order to reach the major conclusion.
To get to the point, the reason that you can’t say:-
For all things, if that thing is a man then that thing is mortal
Socrates is mortal
Therefore Socrates is a man
…is simply because the implication operator in the first premise is a one-way relationship (the implication operator is thus said to be ‘non-commutative’: it has an ‘antecedent’ and a ‘consequent’ which are not interchangeable). “A implies B” just says that if A is true, B is true (and, as a result, that if B is false, A is false). It doesn’t say what happens when B is true (A might be true or false), or when A is false (B might be true or false). It should also be noted that the implication operator says only this: it doesn’t say anything about causality. B might be caused by A (”If I have a haircut, then my hair will be short.”) or A might be caused by B (”If I have less money today than yesterday, then I have paid for something.”) or neither (”If I go outside, then I will go to my Logic class”: going outside is necessary for going to class, but is not the cause of it).
Sorry if this overly long post just confused the issue…
Goose King has detailed this very nicely.
And he’s actually absolutely right about the universal instantiation. I was trying to say that in a more general way when I said B needs to always be true if A is true.
I admit to having simplified. :-\