Saturday, February 13, 2010

Sommers Notation, Part IV

(Part III)

Conjunctive and Disjunctive Predicates

Something we have not directly dealt with before is how to handle something like this:

Every dog is both a mammal and a vertebrate.

In this we are predicating a conjunction of attributes (mammal and vertebrate) to every dog. It turns out that conjunctive predicates are easily handled in Sommers notation. We could translate the above proposition along the following lines:

-D+(+M+V)

Recognizing this allows us to identify some obvious inference rules for conjunctive predicates. For instance, we can obviously have a Rule of Conjunctive Predicate Simplification (CPSimp):

±X+(+Y+Z) ∴±X+Y or ±X+Z

And associative shift works here, as well; from

-D+(+M+V) = Every dog is a mammal and a vertebrate (or, equally, Every dog is a mammal that is a vertebrate)

we can conclude

-(+D+M)+V = Every dog that is a mammal is a vertebrate

We could have more if we choose to elaborate them. But I want to ask the next major question, which is how to handle disjunctive predicates, as in the following:

Every dog is either a mammal or a vertebrate.

We can think this through and use what we know of how to handle conjunctive predicates to handle this new kind of predicate. If every dog is either a mammal or vertebrate, what is definitely ruled out is the case where all the dogs are both non-mammals and non-vertebrates. Thus we can take disjunctive predicates to deny this conjunctive predicate:

-D-(-M-V)

We could develop rules for handling disjunctive predicates, as well; but we will not do so here.

Domains/Universes/Categories

In propositional logic every use of a variable technically requires a domain of discourse (often called a universe of discourse). In Sommers notation, as with any term logic, domain of discourse is much less important, but it still can be defined for every sentence, and usefully so, because every statement is true if and only if it denotes its domain of discourse. In Sommers notation every term has a domain (or, if you prefer, category), and the domain of discourse for any sentence is the intersection of the domains (or, if you prefer, categories) of all its terms.

For convenience, I will symbolize the domain itself (or, if you prefer, category) with a bolded term, like D, and indicate what falls within that domain with /D/. This latter is what I am calling 'category nominalization' or 'domain nominalization'. /D/ consists of everything that is D or nonD, where D and nonD are both taken to belong to the domain or universe indicated by D. Thus if we take the ordinary term 'red', then red is the domain that consists of red and nonred things (we could just as easily call it nonred or red/nonred), i.e., which consists of all and only those things which could intelligibly (even if wrongly) be characterized by ‘red’ and ‘nonred’; thus blue things might fall under this category, but not the number two or the pain in my left hand, because these are a different category (we can meaningfully say of them that they are not the sort of thing that could be either red or nonred). Similarly, /red/ indicates the actual members of this domain. We would use red to talk about the domain of red and nonred things itself; we would use /red/ to talk about what is included or excluded from it. Now, we can use this to handle a particular type of proposition:

Everything is P
Something is P.

In these the subject is the nominalized domain, so they are respectively translated as:

-/P/+P
+/P/+P

Or in other words, every member of the category or domain P is P; some member of the category or domain P is P.

It is by combining domains with conjunctive and disjunctive predicates that we are able to handle noncategorical logic: propositional logic derives from an analysis of predication. To see this we need to learn how to nominalize propositions and therefore use whole propositions as terms.

Propositional Nominalization

In order to get to noncategorical propositions, the question we want to ask ourselves is: How can we handle propositions about propositions? Consider the sentence we noted above:

Some girls who think that all love is easy are unhappy.

If we use [p] to indicate the proposition, "All love is easy" (or perhaps more accurately, to indicate what we mean when we say, "(such) that all love is easy"), we get the following rendering:

+(+G+T+[p])-H

But because [p] is a complex term, we can treat it as one, keeping it in square brackets to indicate that it is a nominalized proposition.

+(+G+T+[-L+E])-H

In nominalizing, we have embedded one sentence in another by treating it as a term. This allows us to do a number of things.

(Part V)

A Beauty in Its Doubt

A Sea-Side Walk
by Elizabeth Barrett Browning


We walked beside the sea,
After a day which perished silently
Of its own glory---like the Princess weird
Who, combating the Genius, scorched and seared,
Uttered with burning breath, 'Ho! victory!'
And sank adown, an heap of ashes pale;
So runs the Arab tale.

The sky above us showed
An universal and unmoving cloud,
On which, the cliffs permitted us to see
Only the outline of their majesty,
As master-minds, when gazed at by the crowd!
And, shining with a gloom, the water grey
Swang in its moon-taught way.

Nor moon nor stars were out.
They did not dare to tread so soon about,
Though trembling, in the footsteps of the sun.
The light was neither night's nor day's, but one
Which, life-like, had a beauty in its doubt;
And Silence's impassioned breathings round
Seemed wandering into sound.

O solemn-beating heart
Of nature! I have knowledge that thou art
Bound unto man's by cords he cannot sever---
And, what time they are slackened by him ever,
So to attest his own supernal part,
Still runneth thy vibration fast and strong,
The slackened cord along.

For though we never spoke
Of the grey water and the shaded rock,---
Dark wave and stone, unconsciously, were fused
Into the plaintive speaking that we used,
Of absent friends and memories unforsook;
And, had we seen each other's face, we had
Seen haply, each was sad.

Thursday, February 11, 2010

Drink, Pilgrim, Here; Here Rest!

Inscription for a Fount
by Samuel Taylor Coleridge


This Sycamore, oft musical with bees,--
Such tents the Patriarchs loved! O long unharmed
May all its agéd boughs o'er-canopy
The small round basin, which this jutting stone
Keeps pure from falling leaves! Long may the Spring,
Quietly as a sleeping infant's breath,
Send up cold waters to the traveller
With soft and even pulse! Nor ever cease
Yon tiny cone of sand its soundless dance,
Which at the bottom, like a Fairy's Page,
As merry and no taller, dances still,
Nor wrinkles the smooth surface of the Fount.
Here Twilight is and Coolness: here is moss,
A soft seat, and a deep and ample shade.
Thou may'st toil far and find no second tree.
Drink, Pilgrim, here; Here rest! and if thy heart
Be innocent, here too shalt thou refresh
Thy spirit, listening to some gentle sound,
Or passing gale or hum of murmuring bees!

Wednesday, February 10, 2010

Sommers Notation, Part III

(Part II)

Now we get to the good stuff: actual inferences.

Tautology

Loosely following Aristotle, we will call a perfect inference any inference that does not require a proof of its validity (because it is clearly valid); one in need of a proof of validity is imperfect. All basic rules of inference are patterns for perfect inferences. For our purposes we will not count as perfect inferences anything with more than two premises, however obviously valid it may be. Thus there are three types of perfect inference: two-premise perfect inferences, one-premise perfect inferences, and zero-premise perfect inferences. It may seem odd to talk about a 'zero-premise' inference; but what is meant is that you don't need a premise to introduce it. Thus all tautologies are zero-premise inferences; they can be introduced whenever you please.

We know that there are two necessarily contradictory types of proposition:

All S aren't S.
Some S aren't S.

Denying these, we get:

All S are S.
Some S are S.

These are tautologies; as will be "All S that are M are S" and "Some S that are M are S". From this we can formulate our first rule of inference, the Rule of Identity (Id):

∴ ±(±S±M)+ (±S)

where M may be empty (i.e., discardable). (In this rule, as in all the others we will use, ± means 'either plus or minus', and the assumption is that you will be consistent in which you choose.) Basically, the rule is that we may introduce a universal or particular tautology whenever we wish, without regard for prior premises. You may add –S+S or +S+S whenever you require. This will be the only zero-premise perfect inference we require.

Immediate Inference

A single-premise perfect inference is also called an immediate inference. The most obvious rule for such inferences is the Rule of Self Inference (SI):

±S±P ∴ ±S±P

Another rule of immediate inference has to do with universal affirmations; it is the Rule of Contraposition (Contrap), which I will break into two parts purely for the sake of clarity:

-(+S)+(+P) ∴ -(-P)+(-S)
-(-S)+(-P) ∴ -(+P)+(+S)

Basically this says that you can infer "All nonP is nonS" from "All S is P", and vice versa.

The third rule of inference has to do with particular affirmations; it is the Rule of Conversion (Con):

+(±S)+(±P) ∴ +(±P)+(±S)

That is,if you have +S+P, you can always conclude +P+S, and if you have –S-P, you can always conclude –P-S So we have rules governing affirmations. But we need rules for doing things with denials. The easiest way to do this is to formulate a rule for converting denials into affirmations; then the rules we have already will apply for all our needs. The Aristotelian claim that any denial is equivalent to an affirmation is very plausible. So we can formulate a Rule of Internal Negation Distribution (IN), which again I will split into two parts for clarity:

±S-(+P) ∴ ±S+(-P)
±S-(-P) ∴ ±S+(+P)

Related to this, we have a Rule of Double Negation (DN) to simplify and expand expressions; any (+T) term can expand to (-(-T)) and any (-(-T)) can simplify to (+T).

A useful additional rule is the Rule of Commutation (Com), which basically says that for any terms we can rewrite (+P+Q) as (+Q+P). If we want to, we can throw in a Rule of Association (Assoc) to handle groupings:

+S+(+Q+P) ∴ +(+S+Q)+P

It's also possible to have a Rule of Relational Simplification (Simp), to handle inferences like "John smiles at Mary; therefore John smiles." Thus we could things like:

±S+(+Q+P) ∴ ±S+Q

One last, and very useful, rule of immediate inference is the Rule of Composition (Comp):

-S+P ∴ -(+S+Q)+(+P+Q)

where Q is an adjective term (whether monadic or relational doesn't matter). This allows you to handle inferences like "All circles are figures; therefore all drawers of circles are drawers of figures" and "All men are mortal; therefore all rational men are rational mortals."

Mediate Inferences

With immediate inferences in hand we are ready to tackle syllogistic, which in term logic covers all mediate inferences (two premises or more). To do this we need to add just one basic rule, the extremely important dictum de omni et nullo (DDO), which can be put in the same form as our other rules to constitute a Rule of Mediate Inference (MI):

-M+P, ±S+M ∴ ±S+P

The basic point is this: whatever is affirmed of all of something is likewise affirmed of what that something is affirmed of.

Given this, we are doing swell. We can show that the syllogism Darapti is valid by the following proof:

1. -M+P premise
2. -M+S premise
3. +M+M Id
4. +M+P MI from 1,3
5. +P+M Conv, from 4
6. +P+S MI from 2,5
7. +S+P Conv from 6

Thus every Darapti syllogism, i.e., every mediate inference of the form "All M is P; All M is S; therefore some S is P" is valid.

It's easy enough to identify the necessary and sufficient conditions for validity in Sommers notation. They are:

(1) A universal conclusion is only validly drawn from universal premises.
(2) A particular conclusion is only validly drawn from a set of premises that contains one and only one particular premise.
(3) The premises in a valid inference sum up to the conclusion.

So this is invalid:

-M-(-S)
-(-P)+S
∴ -M+P

(2) is irrelevant; it meets (1), but the sum of the premises is -M+P+S. This is also invalid:

+S+(-M)
+M+P
∴ +S+P

(1) is irrelevant; it meets (3), but it tries to draw a particular conclusion from two particular conclusions.

Relational Arguments


Consider the following inference:

Some atheist mocks every prayer.
Every Shiite recites a prayer.
∴ Every Shiite recites what some atheist mocks.

In Sommers notation the premises will be:

1. +A1+(M12-P2)
2. -S3+(R32+P2)

The middle term here is P2. Thus (pretty much ignoring the parentheses, which I only put in here to make it easier to translate without accidental shift of meaning) by MI we can conclude:

3. +A1+(M12-S3+R32)

This is clearly a valid syllogism; the first condition for validity is irrelevant, and it meets both the second and the third. And taking this conclusion, by Com we get:

4. -S3+(R32+A1+M12)

Relational Simplification Arguments

Consider the following argument: John smiles at Laura; therefore, John smiles. This is easily handled by Sommers:

1. ±J+(+S±L) premise
2. (±J+S)±L Assoc from 1
3. ±J+S Simp from 2

Similarly, for "John smiles at some person; therefore, John smiles":

1. ±J+(+S+P) premise
2. (±J+S)+P Assoc from 1
3. ±J+S Simp from 2

Associative Shift

Consider the argument:

Someone Thomas studied was Aristotle.
Therefore, Thomas studied Aristotle.

Compare it to:

Someone Thomas studied was the disciple of Aristotle.
Therefore, Thomas studied the disciple of Aristotle.

These are easily handled in Sommers notation by association. The first argument becomes:

1. (±T1+S12)±A2 premise
2. ±T1+(S12±A2) Assoc from 1

And the second:

1. (±T1+S12)+(+D±A2) premise
2. ±T1+(S12+(+D±A2)) Assoc from 1

The form of argument is very simple and straightforward in both cases.

Passive Transformation

Consider the argument, "Paris loves Helen; therefore Helen is loved by Paris." In Sommers notation:

1. ±P1+(L12±H2) premise
2. (±P1+L12)±H2 Assoc from 1
3. ±H2+(±P1+L12) Comm from 2
4. ±H2+(L12±P1) Comm from 3

So far we have considered only categorical propositions. Sommers notation can also handle noncategorical propositions. Before we get to them, however, it will be helpful to look at two other features of Sommers notation: its handling of conjunctive and disjunctive predicates and its handling of domains of discourse.

(Part IV)

Dangle and Hook

I was in a conversation today with someone who tried to enlist me for Amway -- or Quixtar, as the North American portion of the company is now called. He is a genuinely nice guy, very likable, and he threw a decent sales pitch, but from a rhetorical point of view he should have led off with the Exciting Products rather than the Multi-Level Marketing; that immediately raises specters of pyramid schemes, and had the effect not of exciting me but amusing me. Is there really anyone these days who thinks that even legitimate MLM's (Avon, Quixtar, and the like) are a reliable way to make more than pocket change? Perhaps only the salesmen. But perhaps in this economic climate people are more likely to make such leaps out of hope for something better; these are times when even pocket change is tempting for many people.

Also (although he could not have known this, despite knowing that I taught philosophy), he should not have put so much emphasis on the dangling lure of money and nice cars and houses; I had just been reading up on Boethius's Consolation of Philosophy (Relihan's The Prisoner's Philosophy in particular, on which I will probably eventually have a post) and therefore had in my mind very firmly that all-important distinction between the fractured false goods of fortune and true goods. Yes, I am paid relatively little for what I do, but absolutely speaking I need relatively little. Plus, as God and the Devil know, the only material goods that are truly significant temptations for me are books. But despite the fact that I will certainly run into him again and, not being able just to flake, will now have to come up with a gentle way to let down a tenacious salesman who is a genuinely nice guy and is mostly just trying to make a few dollars (he had a spinal injury that limits his job options -- he can't do any sort of lifting and has only a high school education), and despite the fact that I would much rather have spent my lunch working on the design for a hybrid course I'm developing, the whole discussion was really quite worth it: when I teach Boethius later this term I will have a real-life example of the Consolation of Philosophy as a defense against folly.

Had I known I would have had a conversation like this, though, I would have brought a multi-level marketing bingo card. I would not have had Bingo, but I only missed a definition of insanity. As I said, the man in question is a nice guy, but the funniest thing in the whole discussion was that at an early point I thought, "If I tell him I want to do independent research, he's going to scramble to try to make sure that I don't pay attention to critical websites." And when I mentioned later that I'm not the sort of person who makes decisions without research, he gave me some websites but also immediately launched into a spiel about why I shouldn't pay attention to websites by people who 'did absolutely nothing, or thought they were doing it but weren't and so became disappointed when it's really a matter of building an asset over time'. (To his credit, he didn't try, as most MLM people do, to suggest that it worked without effort.) While he would never have admitted it, of course, I could tell from his eyes he was disappointed that I didn't just jump right into the mix.

He did make me want to buy Believe: The Movie, though.

ADDED LATER: Speaking of which, I love these previews:



Edith Stein on Reading John of the Cross

"Pure love" for our holy Father John of the Cross means loving God for his own sake, with a heart that is free form all attachment to anything created: to itself and to other creatures, but also to all consolatins and the like which God can grant the soul, to all particular forms of devotion, etc.; with a hear tthat wants nothing more than that God's will be done, that allows itself to be led by God without any resistance. What one can do oneself to attain this goal is treated in detail in the Ascent of Mount Carmel. How God purifies the soul, in the Dark Night. The result, in the Living Flame and the Spiritual Canticle. (Basically, the whole way is to be found in each of the volumes, but each time one or the other of the stages is predominant.)

Edith Stein, Self Portrait in Letters, 1916-1942, Koeppel, tr., ICS Publications (Washington, DC: 1993) Letter 311 (to Sr. Agnella Stadtmüller), p. 318.

Tuesday, February 09, 2010

Random Musing on Politics

In The Mind of the Maker, Dorothy Sayers suggests that every work of art or craft should be seen as exhibiting three aspects, analogous to the Father, the Son, and the Holy Spirit in Christian theology. Elsewhere she refers to these three aspects as the Idea, the Energy, and the Power. The Idea is what is unfolded in the work of art; the Energy is what we would often call the execution; and the Power is roughly its ability to initiate a response. In principle every artist aims to find the perfect proportion and balance among these three. In practice no one succeeds: everyone's triangle is scalene, sometimes slightly, sometimes severely.

Vico regarded government as a factibile, something made, and I think one can, as a rough but interesting exercise, think of governments as exhibiting these three. And as with works of art, every triangle is at least slightly scalene, and sometimes severely so.

I was somehow put in mind of this by a side comment in Arsen's post on archaism and futurism:

The French Revolution serves as a classical and large-scale example of a real try at futurism. Its henchmen even changed the names of the months on the calendar. The current Tea Party movement serves as a minor example of an archaist reaction to the initiatives of the Obama administration. That administration is wrongly seen as futurist in its intentions. Alas, it’s merely rational—but unfortunately also inept. Its futurist coloration is a very pale shade of pink and derives from the illusion that change can be made almost entirely by magical PR gestures intended to influence public opinion.


This does seem to be a besetting sin -- an artistic heresy, to use Sayers's phrase -- of the Obama administration, one that was actually foreshadowed, I think, by some of Obama's approach to campaigning. The administration takes an Idea, often a very interesting Idea worth developing, but then goes directly for the Power, as if the Idea itself would overwhelm all opposition by a kind of intrinsic magic. This was much the way Obama campaigned, too: ideas robed in a cloud of BOMFOG and glitter.

One is tempted to contrast this with the Bush administration, with all its emphasis on energy and forcefulness and decision and changing the world, and say that that administration was all Energy and no Idea. But this is not right, I think, and would come from accepting too uncritically the administration's own view of itself. In fact, the Bush administration was pretty thoroughly inept, as well: it, too, was an Idea-ridden administration (Spread Democracy! Go to Mars!) that expected Ideas magically to glide directly into Power without the difficult, careful, intricate work -- the actual act of administration -- required to make it happen; it just happens that one of the Ideas with which the Bush administration was enamored was the Idea of what Hamilton called an "energetic magistrate". But that Idea, too, was an Idea that they simply expected to overwhelm with its own intrinsic force; the attempt actually to put it into practice was slipshod, confused, and inept. Their Idea of Energy had no Energy.

I suspect that you might actually find this to be a common problem among American administrations. The degree to which it is a problem no doubt varies from administration to administration -- no government is scalene in exactly the same way. But American-style campaigning, especially at the Presidential level, gives almost no room for making a choice of the President that takes Energy into account. We do not test out administrative competence on the campaign trail; it is not part of our run-up to the election that each candidate is required to spend a week as Acting President so we can see how they handle the day-to-day details. At most we look at their record, and even there we don't look at the day-to-day but at the big things they did. Nobody runs on a campaign platform of quiet and tidy management that slowly and carefully refines and improves what we have; they run on some big idea which they insist will change the way we do things forever. After all, what would be stirring about someone who said that his goal as President would be to improve government accounting practices, reorganize the executive branch to improve efficiency, and to initiate a more systematic ethics review system in order to reduce corruption? It often seems like the last time that this sort of thing was a campaign issue was in the struggle over the spoils system, and like the last time that a President made a name doing this sort of thing was Chester A. Arthur, who put an end to all sorts of corruption by pushing forward a regular civil service -- and that, beneficial as it was, still only got people's attention by being a big, flashy idea.

So perhaps democracies and republics are plagued by the problem of Energy-deficiency. That is indeed very close to how some theorists of democratic government have seen them. Montesquieu's solution (found encapsulated for American's in George Washington's Farewell address) was that this sort of problem could only be remedied by virtue among the people. So perhaps we are doomed, and our good intentions, piling up without the care and craft to put them to good effect, are paving the road into our inevitable future.