I found this Melanie & Mike's page in the Burnside site. Perhaps it is worth discussing. I do not accept M&M' view.

By the way, we've always been puzzled by the following syllogism:

All men are mortal.
Socrates is a man.
[Therefore] Socrates is mortal.

It seems obvious on the face of it but, when it is examined more deeply, one realizes that there is a flaw: one cannot say that "all men are mortal" until one knows whether or not Socrates is mortal. What would Aristotle have said of that?

If he coulda, he woulda consulted Plato.

Logic is comprised of premises that are assumed to be true for the time being, as long as the conclusion would be true if the premises were true.

jimthedog

Really veering off the original question, but it's related to Socrates. And it's funny.

Apologies for the long URL, and what it'll do to everybody's window width

http://www.cartoonbank.com/cartoon_closeup.asp?pf_id=45417&dept_id=1001&mscssid=TWGSQ6X04BSR2MD200GPBQXDMEA63MV4

funny, hyla... but i think round's funnier.



[somewhat-esoteric-movie-reference-e]

I don't know much about the details of Aristotle's thought, but I think he would have said that the major premiss is part of the logical structure of the world. Being mortal is an essential property of being a man. And since Socrates possesses the property of being a man, therefore Socrates possesses any other properties logically contained in it. The inclusion of mortality inside humanity is not inductive but essential.

NicholasW comments: I think he would have said that the major premise is part of the logical structure of the world. Being mortal is an essential property of being a man.

And in the long run, it doesn't matter. The validity of a syllogism is not dependent on the truth of its premises. The syllogism:

All lizards have feathers
All robins are lizards
Therefore, all robins have feathers.

is logically valid. The lack of truth of the major and minor premises has no bearing on its validity nor does it make the conclusion untrue.

All lizards etc.
As my old logic professor, Dr. Albert Hammond, used to warn us, whenever you see a proposition in the form of a syllogism which contains the universal tag "all": BEWARE -- scrutinize the veracity of the premises with all possible care. As Faldage notes, 'all' can produce a perfectly logical conclusion, but not necessarily a true conclusion.

all men

Def: "all men" is a category.

Syllogism:

All syllogisms are arguments from major to minor premise
Socrates is not a premise
Therefore, "All men are mortal..." is not a syllogism

(mortality is essential, as was said elsewhere)

***

Is the following true?

Since the majority of people who have ever lived are living still, probability does not support the major premise of the syllogism in question, namely, that all men are mortal.

***

And here is an interesting piece of rhetoric: "We hold these truths to be self-evident, that all men are created equal and are endowed by their creator with certain inalienable rights..." No, I'm not making a political statement. This fragment contains at least three performative utterances. It is a revolution unto itself.

Dear inselpeter: have you proved that Socrates is still alive?

Dear inselpeter: have you proved that Socrates is still alive?

I think he's proved he doesn't know what a syllogism is.

Is the following true?

Since the majority of people who have ever lived are living still, probability does not support the major premise of the syllogism in question, namely, that all men are mortal.


It's not true, but I once thought it was. On being questioned, I tracked down where I thought I'd got it from, and found it hadn't said it. But perhaps the claim is circulating and I picked it up from somewhere.

If you look at the Earth's population estimates, you see something like this, (which is very rough): 1 thousand million in 1800, 2 thousand million in 1900, 3 in 1930, 4 in 1960, and increasing. Project these forward and back and add them up to either 100 000 or 3 000 000 years ago, it makes no difference which, and you find that our present population is of the order of one fifth of those who have ever lived. But it should reach the majority within a hundred years.

(Repeats disclaimer about vagueness, but it gives the right picture at least.)

Is the following true?

Since the majority of people who have ever lived are living still, probability does not support the major premise of the syllogism in question, namely, that all men are mortal.

Also, since the vast majority of people still alive have not gotten to the point where they would be expected to be dead yet, probability *still does not prove the major premise to be unlikely. Interestingly, we having something akin to the computer halting problem. We can't declare the major premise to be proven false until an infinite amount of time has gone by and someone is still alive.

Interestingly, we having something akin to the computer halting problem. We can't declare the major premise to be proven false until an infinite amount of time has gone by and someone is still alive.

Or like proving there really is a new economy?

Dear inselpeter: have you proved that Socrates is still alive?

No, but I've had a hell of a time convincing him he isn't.

I think he's proved he doesn't know what a syllogism is.

Probably, logic has never been my strong suit. [ignoring titters emoticon] Explain?

Since the majority of people who have ever lived are living still, probability does not support the major premise of the syllogism in question, namely, that all men are mortal.


I have always declared that I am immortal, and will continue to maintain that fact to my dying day!

The original syllogism

All men are mortal.
Socrates is a man.
[Therefore] Socrates is mortal.

This fits the form:

All A are B
C is A
Therefore, C is B

Yours

All syllogisms are arguments from major to minor premise
Socrates is not a premise
Therefore, "All men are mortal..." is not a syllogism

seems to be of the form

All A are B
C is not D
Therefore, E is not A

Does this make sense?

inselpeter wrote

Syllogism:
All syllogisms are arguments from major to minor premise
Socrates is not a premise
Therefore, "All men are mortal..." is not a syllogism


Is this a syllogism? A syllogism necessarily characterises a flow from two connected premises to the conclusion. I don't think that your first statement is correct. The second one is correct, but the third one, I feel, is a non-sequitor; it does not follow from the second.

Regards,
Manoj.

PS: I read somewhere about a great book or an articles, proving many false things using non-sequitors. Does anybody know about it?



Bangalore India
12°58' N, 77°39' E

http://www.geocities.com/kummini/index.html

The discussion on logic reminded me of a passage from the Hitchhiker's Guide To The Galaxy. It was explaing how the population of the universe was zero. It went as follows: There are a finite number of planets that are habitable in the universe while there are an infinite number of planets. As everyone knows any finite number divided by infinitiy is pretty much zero, therefore the population of the universe must be zero.

It is unfortunate, but I see people making conclusions just as valid every day in the newspaper.

...proving many false things using non-sequitors. Does anybody know about it?

My favorite comic Zippy(the Pinhead) by Bill Griffith does it with each "episode".

And to follow up that quote, while attempting to pique the interest of our gutter police, the Guide continues

Population: None.

It is known that there are an infinite number of worlds, simply
because there is an infinite amount of space for them to be in.
However, not every one of them is inhabited. Therefore, there
must be a finite number of inhabited worlds. Any finite number
divided by infinity is as near to nothing as makes no odds, so
the average population of all the planets in the Universe can be
said to be zero.

Art: None.

The function of art is to hold the mirror up to nature, and there
simply isn't a mirror big enough.

Sex: None.

Well, in fact there is an awful lot of this, largely because of
the total lack of money, trade, banks, art, or anything else that
might keep all the non-existent people of the Universe occupied.
However, it is not worth embarking on a long discussion of it now
because it really is terribly complicated. For further
information see Guide Chapters seven, nine, ten, eleven,
fourteen, sixteen, seventeen, nineteen, twenty-one to eighty-four
inclusive.

Max, are you trying to imply that Rouspeter might be wrong? I've been working for years on the assumption that HHGTTG was absolutely right about the population of the galaxy, and that the morons I generally have to deal with on a daily basis (with, of course, the potential exception of the members of this august forum) were simply figments of my fevered imagination, conjured up by me and for me to keep me from feeling lonely.

The next thing that this board will debunk will be bistromathics. I don't know!

Max, are you trying to imply that Rouspeter might be wrong

Sacred blue, no! I just expanded the quote to work in the piece on Sex, hoping to lure the (ominously?) absent Gutter Police Chief to join the thread.

Sacred blue, no! I just expanded the quote to work in the piece on Sex, hoping to lure the (ominously?) absent Gutter Police Chief to join the thread.

Oh, that's all right, then. [Saunters off into the sunset whistling some Gilbert O'Sullivan tune or another emoticon]

Gilbert O'sullivan? They were 2 people and Sullivan wasn't Irish.

jimthedog

Gilbert O'sullivan? They were 2 people and Sullivan wasn't Irish.


Sorry, jimthedog, but Gilbert O'Sullivan is very real, as you will find out if you visit this site
http://www.gosullivan.com/

Stop that... now I'm humming alone, again, naturally, and I think I hear something caribbean in the bachground...

Dear CK and Max: Sadly, it appears that there is a Gilbert O'Sullivan. But his talent seems minuscule compared with that of either Gilbert or Sullivan. The only thing he has going for him is the similarity in names.

The only thing he has going for him is the similarity in names.

As one who grew up hearing Mr. O'Sullivan's biggest hit often, I was well aware of his existence, but did not know that he had changed his first name specifically to create the similiarity to G & S. The other consequence of so much exposure to that most Magdalen of songs is that I have a craving for Schweppes® lemonade every time I think of it.

It seems to me that some very bright people take seriously ideas that to me seem stupid. At the moment I am thinking about the idea that a thousand monkeys typing indefinitely would eventally type Shakespeare's complete works.
In the first place there is no reason to be confident that there is any such thing as infinite time. And even if the logistics of training and maintaining the monkeys could be met,I believe the time elapsed prior to completion of a single correct line would be so great that there could be no hope of completing the whole task.

>It seems to me that some very bright people take seriously ideas that to me seem stupid. At the moment I am thinking about the idea that a thousand monkeys typing indefinitely would eventally type Shakespeare's complete works.

It is of course a silly idea, I mean, a typewriter? Now really, how 20th century! Just give them Word 2000 with the built-in proofing tools and just see what they can do! I meen eye all ways use my spell chequer and it works four me.

Of course it goes without saying that you would need someone to reboot the computers every few days when they crash and update/patch the softwre as appropriate.

<<t is of course a silly idea, I mean, a typewriter? Now really, how 20th century! Just give them Word 2000 with the built-in proofing tools and just see what they can do! I meen eye all ways use my spell chequer and it works four me.>>

Those thousand monkeys will never do it. Their strokes aren't random, so they won't generate Shakespear out of randomness. However, they'll do that a lot quicker on computers, and with more revisons and more trees felled.

Incidentally, have you ever fed a poem through a grammar checker? Make sure you save a copy of the original.

IP

seems to be of the form

All A are B
C is not D
Therefore, E is not A

Does this make sense?

No. Even though the minor premise is itselt a false syllogism, I only see three terms there.

***

As has been said, the truth of a syllogism is not empirical and has only to do with the truth values of its arguments, as defined. It is purely logical and, as such, makes no reference to the "real" world. In addition, there is no logical structure to the world, there are verifiable phenomena.

IP

As terrified as I was of coming back here, I stand by my original syllogism.

Oh dear, we seem to be begging the question again!

OK, he exists, I just can't figure out how to get to the site and still have time to do something besides waiting for it to load. I had never heard of O'sullivan.

jimthedog

On second thought, I could read War and Peace while I'm waiting.

jimthedog

The island, the rock maintains: I stand by my original syllogism

Well, I guess that's OK then, inselpeter. As long as you stand over there by your original syllogism (sic) I needn't fear tripping over you in the dark.

jd questions: Gilbert O'sullivan? They were 2 people and Sullivan wasn't Irish.

Now talk about your three signs of old age! When somebody you were old enough to be curmudgeonly about is before someone's time...

Never have I been so grateful for remembering the other one. I can''t remember what *was his greatest (sic) hit!

F-Age - My hint came with cattle prod attached!!!

Sullivan wasn't Irish.

Sure, Lad, and if his name was Sullivan there is an Irish patriarch in the line who bestowed the name! ... deny it tho he might Sullivan had Irish bloodlines.
wow

My point was that he didn't live in Ireland.

jimthedog

Hello,

`All men are mortal. Socrates was mortal. Therefore, all men are Socrates.' -Found in Linux Fortune Cookies.

Did someone say that academicians are humourless?

Manoj

Bangalore India
12°58' N, 77°39' E

http://www.geocities.com/kummini/index.html

One out of every three persons is suffering from some form of mental illness.
Think of two of your best friends. If they are OK, then it must be you.

My mother always said that the youngest of my older brothers was her Chinese baby despite his blond hair and blue eyes. Around the time he was born in 1962 an article appeared in the Montreal Gazette stating that one out of every five children born today was Chinese. Since here was her fifth child he must therefore be Chinese.

(She was kidding.)

(She was kidding.)

So you say, so you say. Are you certain?

Jackie wrote:
One out of every three persons is suffering from some form of mental illness.
Think of two of your best friends. If they are OK, then it must be you.

No, that's not a syllogism! The first statement only says that on the average, I am suffering from a mental illness with one-third chance. I have no proof to refute that!

Manoj.

Bangalore India
12°58' N, 77°39' E

http://www.geocities.com/kummini/index.html

Jackie, of course, wasn't kidding. But then I happen to know that two of her friends are totally whacked out, so she must be triply sane.

Jackie, of course, wasn't kidding. But then I happen to know that two of her friends are totally whacked out, so she must be triply sane.

Dear Faldage,

Aptually®, I seem to be a part of quite a variety of triangles, and in some I am definitely the only sane one.
So perhaps in the others, I can get balanced out, by losing it entirely, such as when I go skinny-dipping hi, m & bor blurt amorous assertionshi s.

"Property is theft. Therefore theft is property. Therefore this ship is mine". - Zaphod Beeblebrox. This sort of logic is commonly found in my school.

jimthedog

This sort of logic is commonly found in my school.

Jimbo, this sort of logic is commonly found everywhere! Douglas Adams' ability to re-present the commonplace as humour is why the books are so popular.

It annoys me because of the people on the short end.

jimthedog

It annoys me because of the people on the short end.


Yes, if one has been at the short oend of such reasoning, it is harder to find the humour in it. For some reason your post left me singing the song "Don't want no short people round here", a perennial favourite of mine despite being both short and round.

...being both short and round.
You're as cute as a button, too!

Actually, I picture you looking the same as Arthur Dent, except without the beard, which is the opposite of what you say.

jimthedog

Actually, I picture you looking the same as Arthur Dent, except without the beard, which is the opposite of what you say.

Flattering, and pretty accurate as a description of the "real" MaxQ. This cheap knockoff, however, looks nothing like that, as can be seen by taking a trip to the Rogues' Gallery at my idrive account, and looking for oneself.

Flattering, and pretty accurate as a description of the "real" MaxQ. This cheap knockoff, however, looks nothing like that, as can be seen by taking a trip to the Rogues' Gallery at my idrive account, and looking for oneself.

Oh, I dunno. Give you a nondescript dressing gown and a pair of slippers, and that slightly confused and quizzical look would slot right in to HHGTHG. Nobody ever said that Arthur Dent was tall or thin. Only that he was perpetually one behind in the understanding-his-current-situation department ...

Nobody ever said that Arthur Dent was tall or thin.

Somewhere, possibly in the radio scripts which I do not have, Arthur's height is given as around 6 ft - 6 inches tallr than I am.

I usually think of characters being at least tall. I also think of Zaphod as being blue and wrinkly.

jimthedog

>Flattering, and pretty accurate as a description of the "real" MaxQ. This cheap knockoff, however, looks nothing like that, as can be seen by taking a trip to the Rogues' Gallery at my idrive account, and looking for oneself.

I didn't know that it was possible to put faces to some of the names. Now that I know, I've aded to your gallery. In the image I posted, I'm the older, follicly-challenged person.