Begging the Question

[mistermack]

"all humans are mortal" must include all humans called Socrates.

Not until line two, which introduces the minor premiss, to wit: Socrates is human. Please stop ignoring the fact that the the conclusion follows from two separate and independent premisses, the first one proposing that all humans are mortal, and the second one proposing that Socrates is human. If either one is wrong, the conclusion is falsified because of it. Thus, no circularity - or begging the question - in this syllogism. Socrates is definitely mortal only if both premisses obtain. The conclusion that Socrates is mortal depends on both aforementioned premisses being true: 1. All men are mortal, and 2. Socrates was a man.

All humans are mortal.
Socrates is a human.
Therefore, Socrates is mortal

Quite wrong. Line 1 depends on lines 2 and 3. If line 2 is true, and line 3 is false, line 1 is false. That's why it's begging the question. The premise depends on the truth of the conclusion.
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[Coito ergo sum]

"all humans are mortal" must include all humans called Socrates.

Not until line two, which introduces the minor premiss, to wit: Socrates is human. Please stop ignoring the fact that the the conclusion follows from two separate and independent premisses, the first one proposing that all humans are mortal, and the second one proposing that Socrates is human. If either one is wrong, the conclusion is falsified because of it. Thus, no circularity - or begging the question - in this syllogism. Socrates is definitely mortal only if both premisses obtain. The conclusion that Socrates is mortal depends on both aforementioned premisses being true: 1. All men are mortal, and 2. Socrates was a man.

Quite wrong. Line 1 depends on lines 2 and 3. If line 2 is true, and line 3 is false, line 1 is false. That's why it's begging the question. The premise depends on the truth of the conclusion.
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No it doesn't, because Socrates being human is not assumed in the first premise

Dude - you don't know what you're talking about. It's been explained to you several times, with reference to logic textbooks, explaining to you that it is not begging the question.

All A are B.
C is an A.
Therefore, C is a B.

Is not begging the question.

For the same reason,

All men are human
Socrates is a man.
Therefore, Socrates is human.

Is not begging the question.

It is NOT assumed in all men are human that socrates is a man, and therefore it it is not betting the question. It's syllogism, and the conclusion follows from the major and minor premise.

[Coito ergo sum]

Group X has the property Y.
A is a member of group X.
Therefore A has property Y.

That is not begging the question, that is a logical conclusion based on the 2 premises.

Mistermack - see above.

[camoguard]

"all humans are mortal" must include all humans called Socrates.

Not until line two, which introduces the minor premiss, to wit: Socrates is human. Please stop ignoring the fact that the the conclusion follows from two separate and independent premisses, the first one proposing that all humans are mortal, and the second one proposing that Socrates is human. If either one is wrong, the conclusion is falsified because of it. Thus, no circularity - or begging the question - in this syllogism. Socrates is definitely mortal only if both premisses obtain. The conclusion that Socrates is mortal depends on both aforementioned premisses being true: 1. All men are mortal, and 2. Socrates was a man.

All humans are mortal.
Socrates is a human.
Therefore, Socrates is mortal

Quite wrong. Line 1 depends on lines 2 and 3. If line 2 is true, and line 3 is false, line 1 is false. That's why it's begging the question. The premise depends on the truth of the conclusion.
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What'll end up keeping you up at night is the fact that one day we might find a human that was not mortal. Then we'll have to show that Socrates was mortal using an entirely different line 1.

[mistermack]

What'll end up keeping you up at night is the fact that one day we might find a human that was not mortal. Then we'll have to show that Socrates was mortal using an entirely different line 1.

Not if it turns out his name is Socrates. Which begs the question ................
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[camoguard]

If he's dead, he was probably mortal.
Socrates is dead.
So probably, Socrates was mortal.

[mistermack]

Even though we've done Socrates to death (so to speak), I'm still going to try to make my version crystal clear.

Firstly, lets repeat the definition of begging the question. It's assuming, in your premise or premises, what you are trying to prove in the conclusion.

ie, you're USING the truth of your conclusion to try to PROVE your conclusion.

Now lets take the 'classic' sylogism about Socrates :

1) All men are mortal.
2) Socrates is a man.
3) Socrates is mortal.

As far as line 2 goes, there are only two possibilities. It's either true, or it's false. So let's take them one by one.

a) If it's true, then the truth of line 1 depends on the truth of line 3.
Line 1 must be false, if line 3 is false.
All men cannot be mortal, if there is one man called Socrates who isn't mortal. Therefor, you are relying on the conclusion to be true, for your premise to be true. It's a classic case of begging the question.

b) If line 2 is false, then the argument is gibberish. If socrates is a dog, or a gerbil, or a parrot, the whole thing is meaningless and totally illogical.

So there are only two possibilities for this 'classic' bit of logic. It either begs the question, or it's bollocks.
.

[Coito ergo sum]

Even though we've done Socrates to death (so to speak), I'm still going to try to make my version crystal clear.

Firstly, lets repeat the definition of begging the question. It's assuming, in your premise or premises, what you are trying to prove in the conclusion.

ie, you're USING the truth of your conclusion to try to PROVE your conclusion.

Now lets take the 'classic' sylogism about Socrates :

1) All men are mortal.
2) Socrates is a man.
3) Socrates is mortal.

As far as line 2 goes, there are only two possibilities. It's either true, or it's false. So let's take them one by one.

a) If it's true, then the truth of line 1 depends on the truth of line 3.

No, it doesn't. The truth of line 1 does not depend on the truth of line three, and in fact it doesn't matter at all if they are true or false.

It could be:
1. All men are immortal.
2. Socrates is a man.
3. Therefore, Socrates is immortal.

The above is perfectly sound logic, and does not beg the question, even though 1 is false and therefore 3 is false.

Line 1 must be false, if line 3 is false.

Wrong, it may be false, but not MUST be false.

All men cannot be mortal, if there is one man called Socrates who isn't mortal.

Therefor, you are relying on the conclusion to be true, for your premise to be true. It's a classic case of begging the question.

You're not, though. The conclusion is only reached after the premises, and follows from the premises.

b) If line 2 is false, then the argument is gibberish. If socrates is a dog, or a gerbil, or a parrot, the whole thing is meaningless and totally illogical.

It's illogical because the conclusion doesn't follow from the two premises. That's right.

Based on your argument, any syllogism that works is begging the question.

So there are only two possibilities for this 'classic' bit of logic. It either begs the question, or it's bollocks.
.

[/quote]

No, if it is a good syllogism -

All M are X
S is an M
Therefore, S is X.

Doesn't beg the question. You're getting all messed up by making your own assumptions about the words involved. You ASSUME Socrates is a man when reading premise 1, when that is not something to be assumed. Only in premise 2 do we get the statement that Socrates is a man. You take premise 1 and premise 2 and if it NECESSARILY FOLLOWS from those two premises that Socrates is immortal then the syllogism is logical and does not beg the question.

It can be completely untrue, but still perfectly logical.

All birds are oceans.
Tweety is a bird.
Therefore tweety is an ocean.

That's logical, and it doesn't beg the question. Under the syllogism, it necessarily follows that Tweety is an ocean.

To attack this argument you must attack one of the premises. If Tweety is not a bird, but in reality is a dog, the argument is dispatched. If not all birds are oceans, then the argument is dispatched.

At no time, however, does it beg the question.

[camoguard]

Even though we've done Socrates to death (so to speak), I'm still going to try to make my version crystal clear.

Firstly, lets repeat the definition of begging the question. It's assuming, in your premise or premises, what you are trying to prove in the conclusion.

ie, you're USING the truth of your conclusion to try to PROVE your conclusion.

Now lets take the 'classic' sylogism about Socrates :

1) All men are mortal.
2) Socrates is a man.
3) Socrates is mortal.

As far as line 2 goes, there are only two possibilities. It's either true, or it's false. So let's take them one by one.

a) If it's true, then the truth of line 1 depends on the truth of line 3.
Line 1 must be false, if line 3 is false.
All men cannot be mortal, if there is one man called Socrates who isn't mortal. Therefor, you are relying on the conclusion to be true, for your premise to be true. It's a classic case of begging the question.

b) If line 2 is false, then the argument is gibberish. If socrates is a dog, or a gerbil, or a parrot, the whole thing is meaningless and totally illogical.

So there are only two possibilities for this 'classic' bit of logic. It either begs the question, or it's bollocks.
.

You're discussing the differences between a general statement and a specific one. We use the general rule which we might imagine has not been tested on Socrates and are really discussing our expectations. "Mortal" is something that can be determined using other means. But in this case it is determined by a rule we have that all men are mortal. At some level these rules begin as assumptions. Their order of use is the logic.

[mistermack]

You're discussing the differences between a general statement and a specific one. We use the general rule which we might imagine has not been tested on Socrates and are really discussing our expectations. "Mortal" is something that can be determined using other means. But in this case it is determined by a rule we have that all men are mortal. At some level these rules begin as assumptions. Their order of use is the logic.

Yes, you have to start with an assumption. But the rules of the logic state that your assumptions can't include your conclusion. The word "all" is such a little word, we almost ignore it. But what it means is every single living man. So for option a) where line 2 is true, if you don't want to assume the conclusion, that Socrates is mortal, you would have to say :

All men (apart from Socrates, we don't know about him) are mortal.
Socrates is a man
Socrates is mortal? ( is he?, we still don't know about him.)

So you can only prove it by first assuming it. Which isn't a proof at all.
.

[leo-rcc]

Let's try this one more time.

Prime numbers are natural numbers that have exactly two distinct natural number divisors: 1 and itself.
7 is a natural number that has only two distinct natural divisors, 1 and itself.
Therefore 7 is a prime number.

How is this not logical?

[Hermit]

Let's try this one more time.

Prime numbers are natural numbers that have exactly two distinct natural number divisors: 1 and itself.
7 is a natural number that has only two distinct natural divisors, 1 and itself.
Therefore 7 is a prime number.

How is this not logical?

I bet Mistermack will consider your example to be yet another instance of begging the question. He'll never pass Logic 101 at this rate.

[mistermack]

Let's try this one more time.

Prime numbers are natural numbers that have exactly two distinct natural number divisors: 1 and itself.
7 is a natural number that has only two distinct natural divisors, 1 and itself.
Therefore 7 is a prime number.

How is this not logical?

There is a subtle difference here. Are you saying that the DEFINITION of a prime number is a natural number that has exactly two distinct natural number divisors: 1 and itself? So that BY DEFINITION there can't be a number that doesn't conform to that? Because it makes a difference.

If you say that all men BY DEFINITION are mortal humans, that the word man means a mortal human, this is what you get :

1) All mortal humans are mortal.
2) Socrates is a mortal human.
3) Socrates is mortal.

It's not exactly an improvement is it?
.

[Hermit]

Let's try this one more time.

Prime numbers are natural numbers that have exactly two distinct natural number divisors: 1 and itself.
7 is a natural number that has only two distinct natural divisors, 1 and itself.
Therefore 7 is a prime number.

How is this not logical?

There is a subtle difference here. Are you saying that the DEFINITION of a prime number is a natural number that has exactly two distinct natural number divisors: 1 and itself? So that BY DEFINITION there can't be a number that doesn't conform to that? Because it makes a difference.

If you say that all men BY DEFINITION are mortal humans, that the word man means a mortal human, this is what you get :

1) All mortal humans are mortal.
2) Socrates is a mortal human.
3) Socrates is mortal.

It's not exactly an improvement is it?

Yes, reworded like that the argument would definitely constitute an example of begging the question, but would you please stick with what the syllogism actually says? You are fabricating a new argument by adding words that make it patently circular and equating that with the original version which does no such thing. All men are mortal =/= All mortal humans are mortal. Socrates is a man =/= Socrates is a mortal human.

[devogue]

Let's try this one more time.

Prime numbers are natural numbers that have exactly two distinct natural number divisors: 1 and itself.
7 is a natural number that has only two distinct natural divisors, 1 and itself.
Therefore 7 is a prime number.

How is this not logical?

Is 1 a natural number divisor - is 1 not 0.9999999999999999999999...?

If so then 3.5 is as natural and it goes in to seven twice.