Ad Geachem

Peter Geach has argued that :

[A] "Ad hominem arguments. …you start from something he believes as a premise, and infer a conclusion he won't admit to be true. If you have not been cheating in your reasoning, you will have shown that your opponent's body of beliefs is inconsistent, and it's up to him to modify it somewhere. ...But an ad hominem argument may be perfectly fair play. ...A logically sound ad hominem argument does a service, even if an unwelcome one, to its victim - it shows him that his present position is untenable and must be modified. Peter Geach (Reason and Argument: pp. 26 - 27)

[B] Because men are fallible, overall consistency is probably never achieved; and even large scale consistency is difficult to achieve. (Reason and Argument: pp. 6)

Given these two premisses, we have good reason not to believe Geach when he asserts that the ad hominem is an acceptable form of argument.

The Rejoinder

People’s beliefs are either consistent or not consistent. (with all proper restrictions to those capable of having beliefs etc.)

Probably, no individual man ever achieves complete consistency in his beliefs.

So

Probably: For all x, if x is a man, then x has inconsistent beliefs. (that is, given his beliefs, a contradiction can be derived from them by accepted rules of inference)

For all x, if x is a man, then x either has consistent or onconsistent beliefs.

So:

Probably: No x is such that x is a man and x has consistent beliefs.

So, in the individual case, then:

Probably: Peter Geach is not immune from contradictory beliefs.

So, probably, Geach believes both P and ~ P; where P is the thesis that ad hominem arguments are instances of valid forms of argumentation.

(maybe at this point we could add a stipulation that probably means more likely than not.)

Given this, then by his own criteria , [A] and [B]; we ought not to accept Geach’s story about ad hominem arguments.

maudlin stuff

Ulysses

It little profits that an idle king,
By this still hearth, among these barren crags,
Match'd with an aged wife, I mete and dole
Unequal laws unto a savage race,
That hoard, and sleep, and feed, and know not me.

I cannot rest from travel: I will drink
Life to the lees: all times I have enjoy'd
Greatly, have suffer'd greatly, both with those
That loved me, and alone; on shore, and when
Thro' scudding drifts the rainy Hyades
Vest the dim sea: I am become a name;
For always roaming with a hungry heart
Much have I seen and known; cities of men
And manners, climates, councils, governments,
Myself not least, but honour'd of them all;
And drunk delight of battle with my peers;
Far on the ringing plains of windy Troy.
I am part of all that I have met;
Yet all experience is an arch wherethro'
Gleams that untravell'd world, whose margin fades
For ever and for ever when I move.
How dull it is to pause, to make an end,
To rust unburnish'd, not to shine in use!
As tho' to breath were life. Life piled on life
Were all to little, and of one to me
Little remains: but every hour is saved
From that eternal silence, something more,
A bringer of new things; and vile it were
For some three suns to store and hoard myself,
And this gray spirit yearning in desire
To follow knowledge like a sinking star,
Beyond the utmost bound of human thought.

This is my son, mine own Telemachus,
To whom I leave the sceptre and the isle-
Well-loved of me, discerning to fulfil
This labour, by slow prudence to make mild
A rugged people, and thro' soft degrees
Subdue them to the useful and the good.
Most blameless is he, centred in the sphere
Of common duties, decent not to fail
In offices of tenderness, and pay
Meet adoration to my household gods,
When I am gone. He works his work, I mine.

There lies the port; the vessel puffs her sail:
There gloom the dark broad seas. My mariners,
Souls that have toil'd, and wrought, and thought with me-
That ever with a frolic welcome took
The thunder and the sunshine, and opposed
Free hearts, free foreheads- you and I are old;
Old age had yet his honour and his toil;
Death closes all: but something ere the end,
Some work of noble note, may yet be done,
Not unbecoming men that strove with Gods.
The lights begin to twinkle from the rocks:
The long day wanes: the slow moon climbs: the deep
Moans round with many voices. Come, my friends,
'Tis not too late to seek a newer world.
Push off, and sitting well in order smite
The sounding furrows; for my purpose holds
To sail beyond the sunset, and the baths
Of all the western stars, until I die.
It may be that the gulfs will wash us down:
It may be we shall touch the Happy Isles,
And see the great Achilles, whom we knew.

Tho' much is taken, much abides; and tho'
We are not now that strength which in the old days
Moved earth and heaven; that which we are, we are;
One equal-temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.

Alfred, Lord Tennyson

Catholics & Torture

Rev Harrison suggests that Tradition does not, after all, show that torture is intrinsically evil. The letter is a reply to Mark Shea's column.

Wabbing

My blog is worth $6,774.48.
How much is your blog worth?

back to philosophy

After 4 weeks of Law School, I've had enough. It's back to Philosophy!
My expected lifetime earnings graph now makes for truly dismal viewing...

Argumentum ad Geachem

I'm preparing a very short (c. 500 word) article. The argument is that Geach's endorsement of some ad hominem arguments is problematic given his epistemological views. I may put up a draft as a post for comments soon.