My 'Debate' with Kelly Tripplehorn from the "Stanford Challenge"
Offline I decided to email the fellow running the 'Stanford Challenge'
http://i53network.org/The_Stanford_Challenge.html
Here are our exchanges.
#1 Todangst to Tripplehorn
Dear Kelly:
From your site, you write:
"If you answered that the law of noncontradiction is material, then in order to collect your money, you must give an empirical demonstration"
What other types of demonstration are there?
"of where the law of noncontradiction is located."
Simple. In a brain. The demonstration is that I can provide you with the law by telling you about it.
"Moreover, you must tell us, in pounds, the exact weight of the law of noncontradiction."
The law is encoded, neurochemically, in my brain. The bundle of neurons devoted to the concept are in my cerebral cortex... I don't see much value in giving you a weight for these neurons...
"Lastly, if you claim that the law of noncontradiction is located in an object like a symbolic logic textbook, then you must prove that if the textbook was destroyed, the law of noncontradiction would perish with it."
The concept is created a priori, whenever a sentient brain contemplates existence. One concept, multiple representations.
Now, you tell me: how can something exist immaterially? How can an idea exist without a brain? You use the term 'immaterial, I have a challenge for you:
Give me a (positive) ontology for 'immateriality' that does not steal from materialism Do not provide a completely negative description, ( i.e. devoid of any universe of discourse). I offer you 5300 dollars if you succeed.
From Kelly to todangst #2
Thank you for your email.
If the law of non-contradiction is material, then the laws of logic in my brain are different from the laws of logic in your brain. If i said that 2+2=5, and you said that 2+2=4, how would you settle that dispute. Because you see, i could just appeal to my personal laws of logic that exist in my brain, and you could then appeal to your personal laws of logic that exist in your brain. The laws of logic then becomes subjective, and rational discourse is impossible. Anyone could say anything, and they would be right since they are appealing to the laws of logic that exist inside their brain.
The only way to resolve this contradiction is to appeal to a transcendent principal that exists outside of ourselves that governs both of us (and the principal remains true whether or not we agree with it).
Secondly, you write, "How can an idea exist without a brain?"
Is it your position that man created the laws of logic or discovers the laws of logic because if he created the laws of logic, then that means before the evolution of the first brain, 2 plus 2 did equal 5 (and 6, 7, 8,9,10, etc.). So i guess i am asking did man create math or discover math? For if man created math, then what is from stopping me from creating my own math (such as having a system where 2+2=5), and how would you go about trying to rationally prove me wrong.
Yours
Kelly
From Todangst to Kelly #3
Hello,
Thank you for your email.
If the law of non-contradiction is material, then the laws of logic in my brain are different from the laws of logic in your brain.
Sorry, but this is incorrect. There is one universe, impacting upon similar brains, in a similar fashion. For any particular law of logic, we have one law, based on one definition, and multiple representations of that law, in material brains, or books, etc. And we would expect this to be so, since we would expect the same universe with one set of basic metaphysics, to have the same impact on similar brains.
Your response is a basic error that leaves out the fact that the universe is a singular constant. Once you recognize this error, you see that the assumption that there would be 'different laws of logic' is unsubstantiated.
>If i said that 2+2=5, and you said that 2+2=4, how would you settle that dispute. Because you see, i could just appeal to my personal laws of logic that exist in my brain, and you could then appeal to your personal laws of logic that exist in your brain.
This comment is defeated by my above points. One universe with one basic metaphysics. One definition, multiple representations. You must explain how different brains could possibly, sanely glean different metaphysics, given ONE universe with one basic metaphysics.
Hint: You can't.
The only way to resolve this contradiction is to appeal to a transcendent principal that exists outside of ourselves that governs both of us (and the principal remains true whether or not we agree with it).
The only way to solve the 'contradiction' is to refer to the rules that govern the numbers 2 and 4. We can expect that two minds can conceive of the same rule, given that the universe itself is the constant, with its one basic metaphysics.
Secondly, you write, "How can an idea exist without a brain?"
Is it your position that man created the laws of logic or discovers the laws of logic because if he created the laws of logic, then that means before the evolution of the first brain, 2 plus 2 did equal 5 (and 6, 7, 8,9,10, etc.).
You didn't answer the question. In fact you ran from it. So I'll ask it again:
How can an idea exist without a brain. For you to make your claims, you have to be able to answer this question. Please don't respond with another argument from ignorance.
Can you also provide an ontology for immateriality that doesn't steal from materialism? Oh, and please don't send a list of negatives, provide a postive set of attributions.
Thanks.
Kelly to todangst #4
Hello Chris, Thank you for your reply. For this email, I am going to assume that you are an atheist but if you are not, i am sorry that i might have misrepresented your positions. You write that "the universe is a singular constant" How do you know that. Do you now have an answer for Hume regarding the problem of induction. First, you are going to have to establish that the universe is a singular constant, and if you cannot establish that, then there is no reason for someone to say that different laws of logic exist in my brain than from your brain. You write, "How can an idea exist without a brain" My answer is that no idea can exist apart from the mind of God. I will now ask you the question that did math exist before the evolution of a brain. So when 2 organisms were laying next to 2 other organisms, were there 4 total organisms, or does a brain have to authorize that there are 4 total organisms for there to be 4 total organisms. If a brain is not there to authorize the 4 organisms, are there then 5 total organisms. My positive ontology is the Bible as interpreted in the Westminster Confession of Faith. (this is my first principal.) Below is something i wrote to someone else. I am copy and pasting it so that you might better understand my position. The ONLY valid way to argue for the Bible is to presuppose it and if you do not, I completely undermine my own argument. Here is why. "You are right, i cannot prove the Bible, if i did, then i would simply undermine my own position since the Bible is suppose to be believed on by faith, and not on logic. The Bible is my ultimate authority, and if seek to use extra-biblical principals (such as autonomous logic, archeology, autonomous science, etc.) to prove the bible, then those extra-biblical principals become my ultimate authority, and thus i undermine my own position.The Bible is therefore my axiom, I assume that it is true, and then test it. We do the same thing with math, we assume math is true, and therefore we are able to "know" that 2+2=4. We cannot prove math with math without begging the question. We are all forced to beg the question somewhere, but i as a Christian only beg the question once, that is, with the Bible, and through the Bible, i am able to understand the rest of reality." Your first principal is yourself (i assume), and if you presuppose yourself as your ultimate epistemological authority, you can literally know nothing. I believe i establish that on the third question on the 5300 Challenge. Well anyway, thanks for your email. I look forward to hearing from you. Kelly p.s. the next email i receive from you, i may not respond right away. I am pretty busy in general, so please be patient... Talk so you soon.
Todangst to Kelly #6
Hello Chris, Thank you for your reply. For this email, I am going to assume that you are an atheist but if you are not, i am sorry that i might have misrepresented your positions. You write that "the universe is a singular constant" How do you know that.
Hi Kelly.
You are misreading my words as if they are an inductive statement. Instead, I am providing you with simple, basic metaphysics. To exist is to exist as something, to have identity. We know these things axiomatically. We know them a priori.
These axioms are defended through retortion. Any attempt to refute them must rely upon them.
From the fact that something exists, and that it exists as something, and not it's own negation, we have a basic metaphysical basis for deduction.
Do you now have an answer for Hume regarding the problem of induction.
You probably don't know what the 'problem' actually is. You probably, mistakenly, believe that the 'problem' is that one must assume a "uniformity of nature" as both a necessary and sufficient grounds for induction.
This post will refute your commonly held misperceptions as to what the problem is:
http://www.rationalresponders.com/an_easy_argument_to_refute_van_tillian_calvinist_presuppositionalism
And this post will show why there's no 'real problem' with induction:
http://www.rationalresponders.com/why_the_problem_of_induction_really_isnt_a_problem_and_why_theists_dont_even_get_it_right
Even Hume himself argued that induction was not irrational, but merey without an axiomized foundation. However this problem was solved by Kolmogov in 1933.
I have a lengthy examination of Hume's work if you'd like to read it... (have you ever even read his work, let alone the centuries of philosophical responses to it? Do you even know what the 'problem' is?
In addition, you probably are unaware that the scientific method is both inductive and deductive, working from statistical probabily and falsification, meaning that the 'problem of induction' is simply not a problem to science at all.
> First, you are going to have to establish that the universe is a singular constant
I've already answered this: This is simple, basic metaphysics.
You write, "How can an idea exist without a brain" My answer is that no idea can exist apart from the mind of God.
That is not an answer. It's a naked assertion, that relies on an incoherent term "god"
To actualy answer, you must provide:
1) an ontology for immateriality that does not steal from materialism.
2) A method for demonstrating how ideas can exist part from brains.
Please do so in your next response, or concede that you are unable to do so.
I will now ask you the question that did math exist before the evolution of a brain.
No a priori system can exist without a brain, and a universe/set of constants.But this does not mean that people can ignore the basic metaphysics of our universe, so it is not a grounds for arguing that math is entirely subjective or random.
Now, I will again ask you to answer my question above.
My positive ontology is the Bible as interpreted in the Westminster Confession of Faith.
(this is my first principal.)
This is NOT an ontology for immateriality. The bible does not provide a positive ontology for immateriality, or 'transcendence"
Please be honest with yourself and concede that you don't have an answer.
Below is something i wrote to someone else. I am copy and pasting it so that you might better understand my position.
I understand your position - you don't actually have one. Your inability to answer my questions is proof... now, all I need you to do is recognize this. addendum: Here is my lengthy examination of Hume's "An Enquiry Concerning the Human Understanding"
http://candleinthedark.com/hume.html
Now, honestly ask yourself:
Have you actually, really, read Hume?
Have you critically examined what you read?
Have you really understood what the 'problem' is?
Do you realize that even Hume, the one who recognized the problem, was not unseating induction?
Do you know Hume's own solution?
Do you know what the 'arguing to inductive uncertainy' fallacy is?
Have you read the wealth of philosophical responses to Hume?
Do you know the various methods in science that have arisen to deal with the problem? (Hints: statistical probability, falsification)?
If you can't answer these questions, you have no business debating this issue.
Kelly to todangst, #6
Thank you for your email.
I understand the problem of induction enough to know that it cannot be justified, and even if the SEP recognized that you justified your inductive inference with some formula (Bayes' theorem, etc.), then you would still need to justify how you know that formula would continue to operate uniformly in the future. Hume did not take his problem of induction far enough because he did not include math as part of the problem. For instance, every time he added 2+2, he got 4. The next time he added 2+2, there is no way he could have known that he would have gotten 5. In the same way that he could not know that fire caused hotness, he also could not know that 2+2 caused 4. The laws could change at anytime. So my question to you then is how do you know that 2+2 could not equal 5 in the next 10 minutes. Unless the non-Christian knows everything, he can know nothing (and not even that). In order for your answer to be self sufficient you must base it off your first principal (which is yourself). If you simply axiomize math as an independent principal, this is not an acceptable answer, and you have not justified how you know that the laws of math will continue to operate the same in the past as they have in the future. I, as a Christian, can bring back all my information to my first principal, and i expect you to be able to do the same.
In regards to my positive ontology. If you go to the bottom of the 5300 challenge, you will note that i answered all the questions i posed. Lastly, i have already told you that an idea can exist apart from a human brain because all ideas originate in the mind of God. I could not be more clear on this.
If in your next answer you cannot tell me how it is that you are 100% certain, without simply axiomizing your answer, that the laws of math will continue to operate the same way in the future as they have in the past, then there is a good chance you may not receive an email back from me.
I apologize fthat the tone of this email came off harsh.
Anyhow, i do look forward to hearing from you again.
Yours
Kelly
p.s. I noticed that your email was hanniballecturer. Are you a professor?
todangst to Kelly #8
Hello Chris,
Thank you for your email.
I understand the problem of induction enough to know that it cannot be justified,
Kelly you don't understand what the "problem' actually is, nor do you seem to even have a understanding of the centuries of philosophical responses to the 'problem'. In order to debate an issue, you have to actually know what your opponent's position is, and be able to argue it as well as he or she can.
I think that the "problem of induction" is only a problem because: a) Some people look for certainty in induction, when induction is probablistic b) historically, the problem arose before probability theory was mature and c) People assume that a 'problem of induction' somehow justifies questioning induction itself, when in fact this would be a logical fallacy: a reason to doubt an outcome is not a reason to reject the outcome in of itself. You need negating evidence to reject the prediction outright. These are just some of the errors implicit in your misunderstanding of induction.
If you don't look for certainty, and you know about modern probability and statistics, the problem of induction is not a problem at all. The whole (deductively-created) theory of probability and statistics is dedicated to telling us something about "populations" from "samples." It's made for induction.
Basically, today, logicians only see the 'problem' as a problem if and only if one holds to inductive arguments as if they were deductive. The fact that some people are unsatisfied with the various solutions to the problem is hardly a reason to reject induction.
Oh, and the idea that induction can be 'justified' by 'assuming god' is utterly nonsensical. You can't even provide a positive ontology for your claim. Please read here for more:
http://www.rationalresponders.com/supernatural_and_immaterial_are_broken_concepts
And assuming a 'uniformity of god' is even more problematic than assuming a 'uniformity of nature." Please also understand that simply asserting 'the bible is your ontology' is just ridiculous. You know that's not an answer. It's a dodge.
>and even if the SEP recognized that you justified your inductive inference with some formula (Bayes' theorem, etc.), then you would still need to justify how you know that formula would continue to operate uniformly in the future.
You really don't know what the problem is. You assume, erroneously, that the assumption of "uniformity of nature" is both a necessary and sufficient condition for justifying induction and that logicans actually rely on this as a 'response'. This is a common error - usually seen in people who've never read Hume or any philosophical response to Hume.
Science does NOT attempt to justify induction by using the assumption of a uniformity of nature: (Science also works through falsification (rejecting the null hypothesis) and statistical probability, not 'induction', so this is yet another response to the problelm you are probably unaware of...)
From one of the essays I sent to you:
As already mentioned previously, the assumption of a uniformity of nature is a necessary but not a sufficient condition for building inferences from the past to the future. So the assumption is not only circular, it simply fails to provide a justification for such inferences. In addition, Howson & Urbach point out, assuming a uniformity of nature is doubly a nonsolution, since it's a fairly empty assumption. For how is nature uniform? And what, really, are we talking about. What would really be needed are millions upon millions of uniformity assumptions for each item under discussion. We'd need one for the melting temperature of water, of iron, of nickel, etc, etc. For example "block of ice x will melt at 0 Celsius;" for these types of assumptions actually say something. Furthermore, the uniformity of nature assumptions fall prey to meta-uniformity issues - for how are we to know that nature will always be uniform? Well, we have to assume that too. And how do we know that the uniformity of nature is uniform? Ad infinitum. So, to "solve" the philosphical problem of justifying induction by uniformity of nature solutions doesn't really work.
From:
http://www.rationalresponders.com/why_the_problem_of_induction_really_isnt_a_problem_and_why_theists_dont_even_get_it_right
I addressed this error in my previous emails to you. You don't even seem to realize that no one uses the assumption of a uniformity of nature as a sufficient justification for induction - OTHER methods are used.
You might also be interested to learn how assuming a 'uniformity of god' utterly fails to provide a justification for induction, and in fact falls to the same problems faced by someone using a uniformity of nature argument!
http://www.rationalresponders.com/an_easy_argument_to_refute_van_tillian_calvinist_presuppositionalism
> Hume did not take his problem of induction far enough because he did not include math as part of the problem. For instance, every time he added 2+2, he got 4. The next time he added 2+2, there is no way he could have known that he would have gotten 5.
Hume did not discuss mathematics under the problem of induction because math is not inductive!! Math is deductive! There is no problem of deduction! There is no need to justify deduction by assuming a uniformity of nature! Deductions are axiomatically true!
> In regards to my positive ontology. If you go to the bottom of the 5300 challenge, you will note that i answered all the questions i posed.
Kelly. Please. You have not answered a single thing concerning a positive ontology for immateriality. Please stop fooling yourself. Again, please read this essay:
http://www.rationalresponders.com/supernatural_and_immaterial_are_broken_concepts
And actually learn why your position is incoherent.
> Lastly, i have already told you that an idea can exist apart from a human brain because all ideas originate in the mind of God. I could not be more clear on this.
Actually, you could be infinitely more clear. You could begin by defining 'god' coherently, without stealing from materialism. Then you could explain how saying "ideas originate in the mind of god' actually answers the question of how something could be immaterial!
You see, the truth is, you're not answering anything.
> If in your next answer you cannot tell me how it is that you are 100% certain, without simply axiomizing your answer,
Without 'simply axiomizing my answer"? You really don't grasp how justification procedes by providing a deduced, axiomized system, do you?
Funny how you wave your hand at that, yet believe that saying "my ontology is the bible' is actually a coherent response concerning your ontology!
> that the laws of math will continue to operate the same way in the future as they have in the past,
One more time: Math is a deductive system. Mathematical truths are necessary truths. We define numbers, a priori. There is no 'problem of deduction' and deduction does not depend upon a uniformity of nature as both a necessary and sufficient justification for propostions that are tautologically true!
If you can't even figure out that math is deductive, then I see little reason to continue. You've been exposed as someone who doesn't really grasp the issue. Sorry.
I've written the following brief essay to deal with people who hold to the common errors your argument is built upon:
http://www.rationalresponders.com/a_materialist_account_for_abstractions_or_how_theists_misplace_the_universe
I do hope that you actually take the time to actually read Hume some day, and perhaps even learn about what induction is.... Again, I, unlike you, have actually read Hume. I actually know what the problem he identified, and you are completely misrepresenting the problem, and you simply are unaware of how logicians actually deal with the problem. Anyone who tells me that they actually think that logicians rely on 'a uniformity of nature' as the 'solution' to the problem clearly hasn't read anything written in the last 200 years.
My entry on Hume.
http://www.candleinthedark.com/hume.html
If you can't take the time to read Hume, at least read a review of the work where he discusses induction.
Take care, and good luck in your learning.
Kelly to todangst #8
Hello Chris,
This conversation we are having is worthless. In the below email, you misrepresented my position in several spots (for instance i NEVER thought that induction was certain), and on top of that, you are mocking me as if i do not understand what you are saying. Our problems (or disagreements) are not intellectual but ethical, thus debating over the email is a waste of both of our times. If you live close to the Texas area, we should schedule a public debate.
Well you will be in my prayers tonight (even though i know you dont believe in that sort of thing)
Take Care,
Kelly
Todangst to Kelly # 9
Hello Chris,
This conversation we are having is worthless.
Is it really that it's worthless, or is it that you're really not prepared for this conversation, and that you need a way to run off while saving face?
Let's test my hypothesis by seeing you go on to ignore the facts of our discussion and simply focus on your emotional reaction to the discussion.
In the below email, you misrepresented my position in several spots
You need to demonstrate this then.
>(for instance i NEVER thought that induction was certain),
And I never said that YOU said it was certain. I just said that it was a mistake to hold to induction as if it were deduction. I never said it was YOUR specific mistake, per se. So you've jumped to a conclusion and made an erroneous assumption.
And this is probably because you really don't spend much time learning about the points I've sent you.... you're too much in a rush to ignore and avoid the facts of this matter, Kelly. You really should take a look at that, and see for yourself where you're fooling yourself.
This is a complex matter, and no one should make grand pronouncements over a topic that they are fundamentally ignorant in.
> and on top of that, you are mocking me as if i do not understand what you are saying.
Well here we go, as predicted, you're hurt and this email is about your emotions.
I am not mocking you. But it is obvious that you never read Hume, that you really don't know what the 'problem' is, and that you have no idea how logicians and philosophers have dealt with the problem.
And I don't just assert that. I demonstrated that you really don't grasp the situation accurately. I showed that you held (and probably still hold) to the common error that philosophers actually try to justify induction through an assumption of a uniformity of nature. However, again, while this is a necessary condition of induction, it is not a sufficient condition for justifying induction, therefore, other means are required for justifying induction.
Rather than being open to learn about your mistake, and correct it, you choose to react to this all as an insult. You're hurt, and you wish to lash out, rather than just accept that you really don't grasp the issue.
But what's wrong with not knowing something? Isn't it better to concede some ignorance and learn from it? What about that famous christian humility?
> Our problems (or disagreements) are not intellectual but ethical,
You can say this to yourself in order to make yourself feel better, but reality dictates that our disagreements are intellectual.
> thus debating over the email is a waste of both of our times.
Again, in other words, you need to run off, while also saving face.
It's only a "waste of time" to you now that I've demonstrated that you don't know what you're talking about.
Your answers concering the ontology for your postion are proof of that. Your erroneous assumptions about the use of uniformity of nature as a justification for induction are proof of that. Your inability to even recognize that math is deductive, not inductive, is proof of that.
And rather than keep this intellectual, you instead opt to focus on your wounded pride. Again, everyone is ignorant of something. I wasn't born with this information, and I once made the same sort of basic errors you make. I learned.
Why aren't you willing to learn?
Is your wounded pride too overwhelming?
> If you live close to the Texas area, we should schedule a public debate.
I don't live in Texas. However, we can debate on the Rational Response squad any day, any time.
I will also post our emails on the site, now that you've asked to go public.
I must caution you however: you cannot debate an issue over which you are fundamentally ignorant.
> Well you will be in my prayers tonight (even though i know you dont believe in that sort of thing)
And I will think for you, and learn for you, even though I know you don't believe in that sort of thing.
Take Care,
Kelly
Take care Kelly. You've been exposed. I hope you find the courage to concede this to yourself and allow this to inspire you to learn.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Quote:Let me get this straight, he asks you for a proof, and then calls it a 'circle' if you rely on reason for a proof?
Whoa...
If and only if we are talking about the source of logic, in which case using logic results in circular reasoning by definition.
No one is using a logical argument as the source of logic! The problem is that you can't distinguish between discussions of axioms and retortion and classical logic.
If this paradox is beyond your skill to solve -and it probably is, seeing that no one ever has-
There's no paradox, seeing as no one is using logic to support logic. I've already posted something on the axioms used by classical logic, so please review it.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Quote:QED. You seem to understand that at one point at least all worldviews must be circular, hence I will allow one and only one point of circularity.Um...you are not allowed to criticize presuppositions since you are apparently of the opinion that the statement "logic is without foundation" is "true."The problem here is that Todangst and Strafio have made an assertion that all deductive arguments can be reduced to tautologies, but when asked to actually do so to just one argument
Again, this is based on the fact that classical logic is built upon axioms. One such axiom is the law of the excluded middle.
This axiom itself is not part of classical logic, it is not a logical argument. It is defended through retortion.
I repeated this for you above.
(much less use induction to prove that the statement applies to all deductive statements) they fail to do so.
The idea of using induction to show that an axiom applies to all classical deductive statements is a clear expression of your ignorance. It would be done a priori, through proofs, not through inductive methods.
If you are unaware of these things, please consult a logic textbook.
Now, can you do me a favor and deal with these issues?
EDIT: So...exactly how does your epistemic model work?
Mine is pretty simple: God is rational, and He created both nature and man, and as part of the Divine Image gave man the ability to reason. As that nature was made by a rational God, reason and nature can, must, and do correlate.
1) "god" is an incoherent term.
http://www.rationalresponders.com/god_is_an_incoherent_term
Thus your argument fails, because the very first premise is incoherent.
2) Saying "god created the universe" not only suffers the ontological dilemma just outlined, it also says absolutely nothing about justifying logic. It merely asserts that something incoherent made the universe. In short, it's bad cosmology, not a justification for logic.
According to Godel's Theorem as well, as that God is a higher axiomatic system than nature, the axioms of nature are dependent on His own axioms.
I'll leave aside your attempt to invoke Godel...
However, to cut to the quick: The axioms of naturalism include the axiom of existence. How can something be more basic than the axioms of existence and identity.
How can you even refer to your 'god' without relying on the axioms of existence and identity?
I deal with these errors in my essay concerning TAG.
Fine then. I will.
I will challenge that logic (deductive in this case) cannot be accounted for using the naturalistic metaphysic. That isn't to say that you don't use it, just that you can't properly account for it.
Todangst accounts for deductive logic as being a tautology, or in other words an identity statement.
Quote:I'd say that first, any deductive statement is necessarily true, seeing as we can reword any deductive argument into a tautology.There are several problems with this.
There are no problems with this.
I do hope that you are aware that a deductive argument can be reworded into a tautology. I do hope further that you recognize that the law of excluded middle is not 'part of classical logic" but instead an axiom that exists prior to any logical system. If not, then you are ignorant of the very basics of logic. Pick up a copy of Copi and Cohen, or take a course in logic 101 before continuing.
Tautologies themselves are dependent on logic,
Really? How so?
What logical system is PRIOR to the law of the excluded middle?!
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Sir Valiant for Truth wrote:Quote:QED. You seem to understand that at one point at least all worldviews must be circular, hence I will allow one and only one point of circularity.Um...you are not allowed to criticize presuppositions since you are apparently of the opinion that the statement "logic is without foundation" is "true."The problem here is that Todangst and Strafio have made an assertion that all deductive arguments can be reduced to tautologies, but when asked to actually do so to just one argument (much less use induction to prove that the statement applies to all deductive statements) they fail to do so.
Only if you managed to not read what they wrote...
Precisely. I am glad to have witnesses to his dishonesty (or more likely, his inability to even recognize the answer)
I'll repeat the basics for him, again:
Classical logic rests upon the following axioms. These axioms are held to be 'self evident'. We hold that they are are self evident because all syllogisms rely on them, and because they can be defended through retortion. "Retortion" means that any attempt to create a syllogism to refute these axioms will require an argument that relies on these axioms - leading to a self refutation (we call this type of self refutation the "Stolen concept fallacy"
.
The Law of Identity: For things, this law asserts that "A is A" or "anything is itself." For propositions: "If a proposition is true, then it is true." |
All of our syllogisms rely on these laws - that any thing is equal to itself, that tautologies must be true, and that contradictions must be false. Everything has a definite, non-contradictory nature. A metaphysical law of identity would hold that to be perceived or even exist at all it must have a definite, non-contradictory nature, but for our purposes, it is enough to say that If A, then A.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Sir Valiant for Truth wrote:Like I said earlier, if you can work the tautological model down to only being circular, I will accept it because no philosiphy can help being circular in the long run.
I actually disagree with this.
Same here, it's nonsense. First, he's equating logic with a 'worldview'. Next, he's allowing for 'one circle' simply because he knows his own argument is circular. Then:
Logical methods are justified by the laws of identity, non-contradiction and excluded middle. The laws follow from the meanings of our language. So my entire philosophy of logic is based on this one assumption that I don't try to justify - I understand my language. The reason why this assumption is untouchable is that you cannot attempt to refute it without assuming it yourself. Try reasoning without language!
Thanks for again pointing out this out to our friend. Perhaps with enough repetition, he will see it.
I have, over and over, pointed out that these are axioms, not 'logical arguments', that they are prior to classical logic, and that they are defended through retortion, not logical argument.
...But if you really think that you have reduced the syllogism into a tautology, you are gravely mistaken.
That's still not all the possibilities. A tautology is a statement that is true regardless of all the empirical facts. It is the negation of a contradiction.
Yes.
Again, our friend doesn't seem to know what a tautology is...
These are really simple mistakes that even I can avoid, but rather than admitting the mistakes, you defend your position, even though it is obvious, at least to me, that you are not answering the issues, but trying to deflect the issues.
I cannot believe that you are saying this.
I can. The only alternative is for him to concede his error.
When I presented my tautology to you you did three things:
1) You claimed that the minor premise wasn't included when it clearly was.
2) You claimed that tautologies could only be identities.
3) You ignored the syllogism that I wrote, replaced it with a categorical statement and started going on about how this categorical statement wasn't a tautology.Now fair enough, we all miss things and make mistakes in our arguments, but it's a bit rich to go and then accuse me of dodging the issue.
Again, I'm hardly shocked here. All he can do at this point is project out his own errors onto others....
I cover the basics of logic here:
http://www.candleinthedark.com/logic.html
I advise our friend to learn about logic before continuing.
My site is based on Copi and Cohen (10th edition - yeah, I know, not the best one).
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline To be fair to the guy, "learn as you go" is my method of debate as well. I'll start with a position that kind of makes sense to me, even if I don't fully understand it, argue for it as far as I can and then come to understand it better through the rebuttals I face.
Although it's clear that his understanding of concepts like tautology and retortion have been lacking, he's not necessarily being dishonest. The telling point will be how he responds to these criticisms we've made. Will he take note of our position and come to understand us better (even if he doesn't yet agree) or will he continue to repeat himself and attack strawmen?
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Offline To be fair to the guy, "learn as you go" is my method of debate as well. I'll start with a position that kind of makes sense to me, even if I don't fully understand it, argue for it as far as I can and then come to understand it better through the rebuttals I face.
Although it's clear that his understanding of concepts like tautology and retortion have been lacking, he's not necessarily being dishonest. The telling point will be how he responds to these criticisms we've made. Will he take note of our position and come to understand us better (even if he doesn't yet agree) or will he continue to repeat himself and attack strawmen?
"Learn as you go" is a great, time-honored method.
The only thing keeping Sir V from using it is his belief that he already knows it all.
"I do this real moron thing, and it's called thinking. And apparently I'm not a very good American because I like to form my own opinions."
— George Carlin
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Offline To be fair to the guy, "learn as you go" is my method of debate as well.
But that's not debate, per se.
To debate, you must know your opponent's position. If you are learning your opponent's position for the first time, you are no longer debating. You are in 'learning mode'.
Which is fine! But at that point, you must take on the role of a student. Which requires openness, humility, etc. Not dogmatic re-asssertions of your ignorance based position.
Strafio, as evidenced by our own exchanges, you DO learn through this dialectic. But not everyone actually takes part in the dialectic!
I'll start with a position that kind of makes sense to me, even if I don't fully understand it, argue for it as far as I can and then come to understand it better through the rebuttals I face.
And that's great. But to really learn your opponent's position, you must be open, you must be willing to learn it accurately. You must be able to grasp it as he does. So that's sort antithetical to internet debate...
In debate, if you can't argue your opponent's point as well, (or better) than he can, you have no business 'debating'
Although it's clear that his understanding of concepts like tautology and retortion have been lacking, he's not necessarily being dishonest.
It is in fact dishonest to approach such a situation from a position of ignorance AND yet hold that you've 'won' the day and refuted everyone else to the point that you speak in terms of pseudo-pity for the opponent. If you don't even know the oppositions' argument this is just dishonest.
Perhaps 'self dishonest' is the better term.... he's dishonest with himself.
The telling point will be how he responds to these criticisms we've made. Will he take note of our position and come to understand us better (even if he doesn't yet agree) or will he continue to repeat himself and attack strawmen?
Seeing as he looks at it as debate with high stakes, this seems unlikely. However, as we are speaking about it this way, perhaps this will help.
The best way to procede is to procede first as a student, and then, only after mastery, as a debater.
Don't get me wrong, learning through dialectic is more than fine - my concern is that very few people really, actually do it! Its more likely that people will react emotionally and look to just reaffirm their ignorance....
By the way, here's the truth tables for tautology and internal contradiction from my logic website. I pretty much have all the key points from Copi and Cohen there.
Tautology
A statement form that has only true substitution instances is called a tautologous statement form, or a tautology. We can use a truth table to prove that there are no instances where a tautology is false.| p | ~p | p v ~p |
| T | F | T |
| F | T | T |
We refer to such statements as Necessary statements because they are necessarily true, by definition. Any attempt to refute them leads to a self refutation, meaning that any argument that sets up a necessary statement as a false statement is self refuting.
Self Contradiction
A statement form that has only false substitution instances is called a self-contradiction. Such a statement is necessarily false.| p | ~p | p & ~p |
| T | F | F |
| F | T | F |
And here's something I've written to students concerning deductive arguments and tautologies:
Necessary and Contingent Truth
For every argument there corresponds a conditional statement whose antecedant is the conjunction of the argument's premise and whose consequent is the arguemnt's conclusion. For example, an argument using the form of modus ponens:
P É q
p
therefore q
Could be expressed as a conditional statement thusly: "[(p É q) & p] É q." We can read this conditional statement this way: "If it is true that 'p is true, then q is true' AND p is in fact true, then in this case, q is true."
Now why go through all this? Because something very interesting happens to a valid deductive argument when stated in a conditional statement: it becomes a tautology. We learn then that a deductive arguemnt is valid, if and only if its expression in the form of a conditional statement is a tautology.
This all goes back to my orginal expostulation on the nature of deductive arguments: they deal in equivalencies, in equalities, i.e. with a priori truths. So how do we deal with inductive matters, with matters that concern real world phenomena?
Here, we can only deal in contingent truths. If we think back to the deductively invalid forms of affirming the antecedant and denying the consquent, we will recall while there were possible permuations where all true premises led to a false conclusion, we also can recall that there were permuations where this was not the case. Therefore, along with necesssarily contradictory conclusions, these deductively invalid forms also led to contingent truths: claims that may in fact be true. As we will see in the section on inductive logic, we can rely on such forms to give us probable or possible truths.
Once you feel comfortable with the concepts in this section, move on to the section where Truth Tables are used to assess arguments for validity.
Let me know if you have any suggestions for improvements....
- chris
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Don't computers rely on this?
Sounds made up...
Agnostic Atheist
No, I am not angry at your imaginary friends or enemies.
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Offline Hey Tod, this is your own page on logic? I've spent a lot of time in the past looking for sites with fallacy lists. Yours seems top be more complete than most.
I haven't read the whole thing, but I was reading through the fallacies and had a couple suggestions (some self-serving).
The fallacy of the law of averages is the gambler's fallacy. You might mention that. This is an amazing fallacy that many fall into. It's especially common these days with the lottery being nearly universal. Here's an interesting example.
Every once in a while I play the powerball lottery when it's nice and big. I always play $1 on a random number. I mentioned this to someone once and they said, "I never play the random numbers. They come out of a government owned computer and might be rigged." For a minute I almost fell for this. There are cases where that could be true but this isn't one of them, because the way the numbers are finally picked is with ping pong balls bouncing around in tubes because of an airflow. This process is about as random as anything could be. It's sufficiently random. So to be afraid of using the computer generated numbers is silly when the actual method of picking the winning numbers is "sufficiently random."
There is a fallacy on your list that I couldn't find elsewhere so I gave it my own more colorful name. What do you think?
The appeal to force: I call it "the sledghammer fallacy" as in "agree with me or I'll smack you with a sledgehammer."
Related to the sledghammer fallacy is the (my) "last man standing" fallacy. That is, if you refuse to agree with someone and they actually do hit you with a sledgehammer and you die then they win the argument. Yes, they won the actual war of words. But the argument itself has been suspended on account of sledgehammer.
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Offline Hey Tod, this is your own page on logic?
Yes, although some sections rely on Copi and Cohen. It's a subsection of my philosophy website.
I've spent a lot of time in the past looking for sites with fallacy lists. Yours seems top be more complete than most.
One of my hobbies is collecting different informal fallacies!
One problem for the site is that it needs a major format revamp. I am consider a wiki-style.
I haven't read the whole thing, but I was reading through the fallacies and had a couple suggestions (some self-serving).
Make as many suggestions as you like!
The fallacy of the law of averages is the gambler's fallacy. You might mention that.
Very good suggestion. There are many fallacies with more than one name, I'll add this.
This is an amazing fallacy that many fall into. It's especially common these days with the lottery being nearly universal. Here's an interesting example.
Every once in a while I play the powerball lottery when it's nice and big. I always play $1 on a random number. I mentioned this to someone once and they said, "I never play the random numbers. They come out of a government owned computer and might be rigged." For a minute I almost fell for this. There are cases where that could be true but this isn't one of them, because the way the numbers are finally picked is with ping pong balls bouncing around in tubes because of an airflow. This process is about as random as anything could be. It's sufficiently random. So to be afraid of using the computer generated numbers is silly when the actual method of picking the winning numbers is "sufficiently random."
Right. I don't think people bother to think it through.
There is a fallacy on your list that I couldn't find elsewhere so I gave it my own more colorful name. What do you think?
The appeal to force: I call it "the sledghammer fallacy" as in "agree with me or I'll smack you with a sledgehammer."
Heh! Good... I'll add that too.
Related to the sledghammer fallacy is the (my) "last man standing" fallacy. That is, if you refuse to agree with someone and they actually do hit you with a sledgehammer and you die then they win the argument. Yes, they won the actual war of words. But the argument itself has been suspended on account of sledgehammer.
This is a very good one, because it is how many historical debates actually go: the winners win when by procreating more supporters.... losers lose when the last supporter dies out.
You see this in psychology quite a bit - certain styles die out with the last known user of the therapy dies, without any interns.
Thanks man.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline ...and yet...both of my objections a page and a half ago (inherent circularity and an unfounded and unproven assertion) to the tautological source of deductive logic origins are still up.
Like I said earlier, if you can get this down to only circularity I will accept the position.
In fact, only the second one has even been attacked, and that attack only proved that you don't know what you are talking about.
If the tautological logical origins model is true, reducing my syllogism to a tautology should be a simple affair. It wasn't
In fact, what I should have asked, but didn't because I knew that it was well beyond any of your skills, is to use induction to prove that all deductive arguments can be reduced into tautologies, which is what the original assertion was.
That assertion has not been either exemplified, and has most diffinitively not been proven. It is your PREsupposition.
Until you succeed in justifying your own position, I don't have to listen to a word you say, but I find it remarkable that you will so easily turn to ad hominems and forget that you must first answer properly my own objections.
"Truth is the cry of all, but the game of the few." George Berkeley
"Truth is always strange — stranger than fiction." Lord Byron
Fixing the world, one dumb idea at a time.
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Offline ...and yet...both of my objections a page and a half ago (inherent circularity and an unfounded and unproven assertion) to the tautological source of deductive logic origins are still up.
Like I said earlier, if you can get this down to only circularity I will accept the position.
In fact, only the second one has even been attacked, and that attack only proved that you don't know what you are talking about.
If the tautological logical origins model is true, reducing my syllogism to a tautology should be a simple affair. It wasn't
In fact, what I should have asked, but didn't because I knew that it was well beyond any of your skills, is to use induction to prove that all deductive arguments can be reduced into tautologies, which is what the original assertion was.
That assertion has not been either exemplified, and has most diffinitively not been proven. It is your PREsupposition.
Until you succeed in justifying your own position, I don't have to listen to a word you say, but I find it remarkable that you will so easily turn to ad hominems and forget that you must first answer properly my own objections.
Your position has been discussed and refuted. Why do you refuse to see it?
"I do this real moron thing, and it's called thinking. And apparently I'm not a very good American because I like to form my own opinions."
— George Carlin
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Offline Turns out you were right Tod. Rather than listen to the clear objections I made to him in the last page it was a "I don't care what you say! I've won the day!" little ditty.
...and yet...both of my objections a page and a half ago (inherent circularity and an unfounded and unproven assertion) to the tautological source of deductive logic origins are still up.
You mean, they've been soundly answered but you can't understand them. I gave clear answers to both objections in the first post. From there the difficulty has been repeating and re-wording these answers in a way that you might understand them.
If the tautological logical origins model is true, reducing my syllogism to a tautology should be a simple affair. It wasn't
It was. The difficulty was (and still is) in getting you to read it properly. In my last post I summarised the three things you did in response to my answer. The first one proved you hadn't read it properly, the second proved you didn't fully understand what a tautology is, the third proved that you were more interested in attacking a stawman rather than what I wrote.
While we all give bad answers from time to time, when the flaws in yours were pointed out, you just repeated them.
Until you succeed in justifying your own position, I don't have to listen to a word you say, but I find it remarkable that you will so easily turn to ad hominems and forget that you must first answer properly my own objections.
Ah... this explains everything.
You see, I did justify my position but you weren't listening to a word I say.
Seriously though, what did you come onto this site to do?
Did you read a script on "how to refute atheists" from some Christian website or did you actually want to use logic to debate us. Re-read my last post to you again. It re-explained my points and gave a careful critique of your previous objections.
I'm not sure why you're complaining about ad-homs either.
You've been accusing us of being closed minded and repeating our 'presuppositions' right from the start. If you want to be taken seriously as a rational person then go back to my last post and read it carefully, or maybe take Tod's advice and read a book on logic and come to understand it better.
It's not that you disagree with us that is the problem. It's that your manner and method of debate, to put it bluntly, sucks!
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Offline ...and yet...both of my objections a page and a half ago (inherent circularity and an unfounded and unproven assertion) to the tautological source of deductive logic origins are still up.
No, they are not. Both were refuted. Numerous times.
Your inability to recognize that you've been refuted is not a defense.
Again:
There is no cicularity problem, as axioms are not part of classical logic.
Point 1 is refuted.
And axioms are defended through retortion, not logical argument. Arguments defended through retortion are NECESSARILY TRUE.
Point 2 is refuted.
Your entire argument is thus refuted.
You don't even seem to grasp what tautologies are, or what retortion is, or even how axioms precede a logic (for logics that require axioms, not all do)
This isn't a debate... you should be paying us tutoring fees.
Until you succeed in justifying your own position, I don't have to listen to a word you say
This coming from a guy who steadfastly refuses to answer any question concerning his own postion!
I just need to know, are you using the "hands over the ears, I can't hear you!' method, or are you sticking out your tongue and shouting "Nyah Nyah"?
Here's a challenge for you: Refute the axioms of classical logic. If they are 'unsupported', it should be an easy task for you.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline
Your position has been discussed and refuted. Why do you refuse to see it?
I don't think he 'refuses' to see it. I think he simply isn't able to see it.
Turns out you were right Tod. Rather than listen to the clear objections I made to him in the last page it was a "I don't care what you say! I've won the day!" little ditty.
He has little choice, as I doubt he grasps the points made here.
In addition, he runs for the hills whenver I ask him to back up his own argument (i.e. provide an ontology for god, show how his 'god theory" works, etc.)
...and yet...both of my objections a page and a half ago (inherent circularity and an unfounded and unproven assertion) to the tautological source of deductive logic origins are still up.
You mean, they've been soundly answered but you can't understand them. I gave clear answers to both objections in the first post. From there the difficulty has been repeating and re-wording these answers in a way that you might understand them.
Precisely.
If the tautological logical origins model is true, reducing my syllogism to a tautology should be a simple affair. It wasn't
It was.
It was quite simple. His main defense is his inability to recognize that his challenge has been answered.
The difficulty was (and still is) in getting you to read it properly.
Bingo.
In my last post I summarised the three things you did in response to my answer. The first one proved you hadn't read it properly,
Yes.
the second proved you didn't fully understand what a tautology is,
Yes!
the third proved that you were more interested in attacking a stawman rather than what I wrote.
I think he has no choice but to attack a strawman, seeing as he's hasn't proven himself capable of understanding the actual argument.
While we all give bad answers from time to time, when the flaws in yours were pointed out, you just repeated them.
Yes.
Until you succeed in justifying your own position, I don't have to listen to a word you say, but I find it remarkable that you will so easily turn to ad hominems and forget that you must first answer properly my own objections.
Ah... this explains everything.
You see, I did justify my position but you weren't listening to a word I say.
I already have him on record as saying he refuses to read or learn the counter position, and that he takes theistic arguments on trust.
He says it on page 3 in this thread:
http://www.rationalresponders.com/forum/sapient/atheist_vs_theist/6412
Seriously though, what did you come onto this site to do?
Did you read a script on "how to refute atheists" from some Christian website or did you actually want to use logic to debate us. Re-read my last post to you again. It re-explained my points and gave a careful critique of your previous objections.I'm not sure why you're complaining about ad-homs either.
You've been accusing us of being closed minded and repeating our 'presuppositions' right from the start. If you want to be taken seriously as a rational person then go back to my last post and read it carefully, or maybe take Tod's advice and read a book on logic and come to understand it better.
It's not that you disagree with us that is the problem. It's that your manner and method of debate, to put it bluntly, sucks!
Well put. I'd also add in that he simply has no grasp of what logicians actually have to say about deductive logic.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline This is my last post, unless I see something that actually needs refuting. At least this way I can retain some regards of civility which you appear to not hold. (Even if I am uncurably dense, I have tried to remain civil, a restraint that does not appear to be mutual.
Perhaps if I show why the very nature of a tautology and a deductive syllogistic argument are not mixable, you may concede the point, but I doubt it.
A tautology is one of two things: an identity statement (a = a) or an organizing statement (a = either b or non B) Both of these are inherently true (given the laws of logic) but both of these also say nothing.
a = a is begging the question, and a = either b or non b really does say nothing because it is like saying "rocks are either living or non-living." While the statement is true, as that the categories "either living or non-living" include every possible thing in existance, the statment has only given us the information a is, and without any further information it is impossible to say anything about the nature of a.
This contrasts sharply with the deductive syllogism, which follows a carefully constructed set of rules that is set up to use two bits of information to deduce a third as a nessecity. A deductive syllogism derrives information, where as a tautology does not.
A deductive syllogism starts with a major premise and a minor premise, then derrives a conclusion.
The general format is that the major premise is a categorical general rule, that applies everywhere in the universe. This cannot be a tautology itself because a tautology is in the form of a = a, where as a categorical statement follows the statement of all a's belongs to the category b. The one cannot be made into the other.
The minor premise is a specific fact ,usually -but not always- pertaining to a specific object. Usually this is another categorical statement that is formed as specific object a belongs to the category b. Again, this cannot be reduced into a tautology.
So the general rule along with the specific fact, combined with the connection between the specific fact and the general rule to make the argument sound results in the creation of new information: the conclusion.
Usually this follows the general format of:
All a's belong to the category of b
Specific a belongs to category a
Therefore specific a belongs to category b
This is as simple as the deductive syllogism can get. Usually when put into grammatical form information can be implied, but if that information is not present, the syllogism fails.
A tautology, however, is already in it's maximum complexity form in a = either b or non b. As that the conclusion a belongs to category b does not follow from that, the syllogism fallls apart.
Try to prove me wrong. It is logically impossible (unless you are making up your own definition to tautology, in which case none of your arguments are proper logic.)
"Truth is the cry of all, but the game of the few." George Berkeley
"Truth is always strange — stranger than fiction." Lord Byron
Fixing the world, one dumb idea at a time.
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Offline The identity principle is question begging?
It is to laugh
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Offline A tautology is one of two things:
Incorrect already.
You gave two examples of a tautology, an identity and an excluded middle. A more general definition is the negation of a contradiction. If a contradiction is necessarily false then its negation must be necessarily true.
Another point is that we don't need to assume laws of logic either.
These come from the meanings of the words of our language.
(remember that dialogue I did for why the law of non-contradiction is a necessity?)
This contrasts sharply with the deductive syllogism, which follows a carefully constructed set of rules that is set up to use two bits of information to deduce a third as a nessecity. A deductive syllogism derrives information, where as a tautology does not.
You perhaps missed this example last time I gave it so I'll repeat it.
Like you say, a deduction shows that if the premises are true then the conclusion must also be true. That means that:
'premises' & ¬'conclusion' must be a contradiction and that ¬'premises' or 'conclusion' (the negation of the contradiction above) must be a tautology.
However, as the word 'tautology' is causing dispute, let's leave it out for now and look at other ways the naturalist can justify the rules of deduction. My starting assumption is that language is as it is. (a pretty necessary assumption seeing as I'm writing it it!)
Aristotle's syllogisms are over 2300 years old and are getting on a bit. They are only capable of simple two premise deductions. Modern Predicate logic allows for much more complex deductions and, in my opinion, is a lot easier and more intuitive to work with. The way they will prove that a conclusion follows from the premises is with algorithms like the tree method.
The method first shows that the premises and the negation of the conclusion contradict each other. If so, the deduction is valid and the following apply:
By the law of non-contradiction: the premises and negated conclusion cannot both be true - atleast one of them must be false.
By the law of the excluded middle: If the negated conclusion isn't true then the conclusion must be true.
So we end up with the following:
If the premises are true then the negation of the conclusion must be false and that means that the conclusion itself must be true.
The rules of logical deduction are constructed out of the law of non-contradiction and the law of the excluded middle. In turn, both of those laws are required by the meaning of our language.
A tautology, however, is already in it's maximum complexity form in a = either b or non b. As that the conclusion a belongs to category b does not follow from that, the syllogism fallls apart.Try to prove me wrong. It is logically impossible (unless you are making up your own definition to tautology, in which case none of your arguments are proper logic.)
I don't think that we're the ones in error of the definition of tautology.
Wikipedia's tautology page disagrees with you.
The Stanford Encyclopedia didn't have a whole article dedicated to tautologies but if you'll notice that the articles use them in a way that we would use them. A tautology is something that is true by definition, and this is synonymous with the negation of a contradiction. If P is a contradictory proposition then ¬P is a tautology.
This is my last post, unless I see something that actually needs refuting. At least this way I can retain some regards of civility which you appear to not hold. (Even if I am uncurably dense, I have tried to remain civil, a restraint that does not appear to be mutual.
With your accusations of us dodging the point while refusing to read what we say carefully, you've not exactly been an angel yourself. I'm not sure what your intentions have been on this but unless you read what we say more carefully then rational debate is going to be impossible and we're just going to get more and more frustrated with you.
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Offline This is my last post, unless I see something that actually needs refuting.
Keep whistling past the graveyard if it helps you sleep at night.
I've already demonstated that deductive arguments can be rewored as tautologies. You lack even enough common decency to cut and paste the argument, let alone respond to it.
And, again, this is basic knowledge.
Necessary and Contingent Truth
For every argument there corresponds a conditional statement whose antecedant is the conjunction of the argument's premise and whose consequent is the arguemnt's conclusion. For example, an argument using the form of modus ponens:
P > q
p
therefore q
Could be expressed as a conditional statement thusly: "[(p > q) & p] > q." We can read this conditional statement this way: "If it is true that 'p is true, then q is true' AND p is in fact true, then in this case, q is true."
Now why go through all this? Because something very interesting happens to a valid deductive argument when stated in a conditional statement: it becomes a tautology. We learn then that a deductive argument is valid, if and only if its expression in the form of a conditional statement is a tautology.
This all goes back to my orginal expostulation on the nature of deductive arguments: they deal in equivalencies, in equalities, i.e. with a priori truths. So how do we deal with inductive matters, with matters that concern real world phenomena?
Care to respond to this refutation of your claim?
Or will you dodge it again? Like you've dodged every single request that back up your own arguments?
At least this way I can retain some regards of civility which you appear to not hold. (Even if I am uncurably dense, I have tried to remain civil,
There's nothing more insulting than someone pretending that their arguments have not been answered. This is how you've behaved your entire time here. This is the height of rudeness.
Perhaps if I show why the very nature of a tautology and a deductive syllogistic argument are not mixable,
You couldn't be more wrong.
A deductive argument is valid, if and only if its expression in the form of a conditional statement is a tautology.
Perhaps if you realized that you were already talking to people well versed in logic... you'd stop asserting this nonsense.
While the statement is true, as that the categories "either living or non-living" include every possible thing in existance, the statment has only given us the information a is, and without any further information it is impossible to say anything about the nature of a.
Tautologies tell us nothing about the real world outside of our brains... they are a priori.
But so too are deductions!
This is your error.
This contrasts sharply with the deductive syllogism,
No, it does not. Deductive arguments deal in equivalencies. Nothing 'new', in any inductive or abductive sense, is discovered in deductions either...
Saying that A = B and B= C, therefore A = C merely states that A, B and C are the same entity/category. Nothing about the real world is expressed (i.e. nothing inductive) merely one term is said to be identitical to another.
All unmarried men are bachelors
Mark is a bachelor
Ergo, he is unmarried.
Seeing as 'umarried' is identical to 'bachelor' in this argument, nothing 'new', in any inductive sense, is discovered.
Adapted from Copi and Cohen
Deductive arguments are akin to mathematical equations: they present a series of categories or definitions in a series of equivalencies. For this reason, the conclusion of a deductive argument necessarily follows from its premises, in the same way that "4" follows from the "premises" of "2+2=". In my opinion, the most elegant form of a deductive argument is Aristotle's syllogistic logic, or classical deductive logic.
We can call a deductive logical system an a priori system. This means that we can make up such a system without any observation or experimental examination.We can create a set of categories like squares or circles or letters, and a set of self consitent rules that follow a set of definitions, all without having to ever experience such "things". Philosophers like to say that a "brain in vat" set apart from the rest of the universe could create an a priori system.
Try to prove me wrong.
We already have.
Please go pick up a book on logic. Read the first chapters. Learn your errors.
When you finally learn that deductive arguments can be reworded as tautologies, you can come back and apologize...
Better yet, why not ask someone impartial, who actually knows something about logic, if this is true:
A deductive argument is valid, if and only if its expression in the form of a conditional statement is a tautology.
Go on.
Learn. Surprise us.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline http://www.mathpath.org/proof/proof.inference.htm
Natural Deduction uses two kinds of rules: Rules of inference and rules of replacement. (The term "rule of inference" is often used to cover both types.) The former are tautologous conditionals (that is, valid wffs of the form A É B; in other words a string of the form A É B which evaluates to T for all truth value assignments to the propositional variables), and the latter are tautologous biconditionals (that is, valid wffs of the form A º B). The former apply only to entire lines of proof, while the latter apply to components within a line as well as to the whole line. Any tautologous conditionals and biconditionals could serve as valid rules of inference; but these are infinite in number. A small number of tautologies are chosen that are able to transform other wffs. Here is a popular set, known as Copi's set of rules [1].
Table 1. Inference Rules
Modus Ponens (MP)
p É q
p
_________
\ q Modus Tollens (MT)
p É q
~q
_________
\ ~pHypothetical Syllogism (HS)
p É q
q É r
_________
\ p É rDisjunctive Syllogism (DS)
p Ú q
~p
_________
\ qConstructive Dilemma (CD)
(p É q) .(r É s)
p Ú r
_________
\ q Ú sDestructive Dilemma (DD)
(p É q) .(r É s)
~q Ú ~s
_________
\ ~p Ú ~rSimplification (Simp.)
p.q
_________
\ p Conjunction (Conj.)
p
q
______
\ p.qAddition (Add.)
p
_______
\ p Ú q
| De Morgan's Theorem (DM) | ~(p.q) º (~p Ú ~q) ~(p Ú q) º (~p.~q) |
| Commutation (Com.) | (pÚq) º (qÚp) p.q º q.p |
| Association (Assoc.) | [(pÚq)Úr] º [pÚ(qÚr)] [p.(q.r)] º [(p.q).r] |
| Distribution (Dist.) | [p.(qÚr)] º [(p.q) Ú (p.r)] [p Ú (q.r)] º [(p Ú q).(p Ú r)] |
| Double Negation (DN) | p º ~~p |
| Material Implication (M. Imp.) | (p É q) º (~p Ú q) |
| Transposition (Trans.) | (p É q) º (~q É ~p) |
| Material Equivalence (M. Equiv.) | (p º q) º [(p É q).(q É p)] (p º q) º [(p.q) Ú (~p.~q)] |
| Law of Exportation | [(p.q) É r] º [(p É (q É r)] |
Note, again, that both the inference rules and the rules of replacement are tautologies.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline From the same site: My own argument already quoted above (twice) is given:
1. Modus Ponens (MP): The original Latin name of the rule is Modus Ponendo Ponens, which means the method (modus) that affirms the consequent (ponendo) by affirming the antecedent (ponens). If p É q is true, and p is true, then q is true. A shorter way of saying this is 'if p É q and p then q.' A way of writing this is:
p É q
p
_________
\ q
Now let us consider an 'instance' of this wff by substituting declarative sentences to stand for p and q. For instance, let p stand for 'the sun is shining' and q for 'Mary is at the beach'. Then the instance of MP is:
So why is this a tautology? To see it, let us rewrite 'if p É q, and p, then q'. It becomes ((p É q) . p) É q. Look at its truth table.If the sun is shining, then Mary is at the beach.
The sun is shining.
Therefore Mary is at the beach.
| p | q | p É q | (p É q).p | [(p É q).p] É q |
| T | T | T | T | T |
| T | F | F | F | T |
| F | T | T | F | T |
| F | F | T | F | T |
Since all entries in the last column are T's, we have a tautology. That is, regardless of the assignment of truth values to its variables, the wff [(p É q).p] É q always yields a T value.
2. Modus Tollens (MT): If p É q is true, and ~q true, then ~p is true. The latin name is Modus Tollendo Tollens, which means by denying (tollendo) the consequent, we deny (tollens) the antecedent of the conditional.
If the sun is shining, then Mary is at the beach.As above, a truth table would show that the wff representing MT, namely [(p É q). ~q] É ~p, is a tautology.
Mary is not at the beach.
Therefore the sun is not shining.
3. Hypothetical Syllogism (HS): From p É q and q É r to infer p É r. Also known as "chain reasoning", a hypothetical syllogism is not limited to two premises. Any number of premises can be used, provided that each one preserves the chain: the consequent of the first conditional must be the antecedent of the second.
If the sun is shining, then Mary is at the beach.[(p É q). (q É r)] É (pÉ r) is a tautology.
If Mary is at the beach, then she is swimming.
If she is swimming, then she will be tired tonight.
Therefore, if the sun is shining, Mary will be tired tonight.
The rest of the site gives such proofs for several other rules of inference, and is based also on copi and cohen:
I. M. Copi, Symbolic Logic, 5th Edition. (New York: Macmillian, 1979)
I want to stress that these proofs are taught in logic 101.
Welcome to refutation city, VST. Population: you.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Sir Valiant for Truth wrote:This contrasts sharply with the deductive syllogism, which follows a carefully constructed set of rules that is set up to use two bits of information to deduce a third as a nessecity. A deductive syllogism derrives information, where as a tautology does not.
You perhaps missed this example last time I gave it so I'll repeat it. ike you say, a deduction shows that if the premises are true then the conclusion must also be true. That means that:
'premises' & ¬'conclusion' must be a contradiction and that ¬'premises' or 'conclusion' (the negation of the contradiction above) must be a tautology.
This is a very nice and direct way to explain this point.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Out of all of it, here was the thing that set off my bullshitometer:
A tautology is one of two things: an identity statement (a = a) or an organizing statement (a = either b or non B) Both of these are inherently true (given the laws of logic) but both of these also say nothing.
Is god god? a=a
Yes? You're begging the question!
The god I believe in either exists or doesn't exist? a = b or ~b
Yes? This truth tells me nothing.
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Offline From the same site: My own argument already quoted above (twice) is given: 1. Modus Ponens (MP): The original Latin name of the rule is Modus Ponendo Ponens, which means the method (modus) that affirms the consequent (ponendo) by affirming the antecedent (ponens). If p É q is true, and p is true, then q is true. A shorter way of saying this is 'if p É q and p then q.' A way of writing this is: If the sun is shining, then Mary is at the beach.
p É q
p
_________
\ q
Now let us consider an 'instance' of this wff by substituting declarative sentences to stand for p and q. For instance, let p stand for 'the sun is shining' and q for 'Mary is at the beach'. Then the instance of MP is:
The sun is shining.
Therefore Mary is at the beach.
Hey Tod, I don't appreciate your clearly sexist logic. Feminist mathematicians have criticized the masculine bias of the modus ponens for longer than you would dare to admit. The word "ponendo" is clearly etymologically related to the word "pudendum". The p (read pee pee) is trying to get into É, without even asking permission. Your entire giberring ululation is speckled throughout with these phallic p's and q's, as if you're cumming on the face of female intuition. Please spare us your patronizing, patriarchal and partisan ponens.
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Offline That's pretty much the sort of reply I expect.
Anyway, I've now quoted Copi and Cohen in more detail, demonstrating unquivocablly that rules of inference in deduction can be (and must be, if they are valid) reworded into tautologies, completely refuting our friend.
Let's see if he has the intellectual honesty to concede his blunder.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline That's pretty much the sort of reply I expect.
Anyway, I've now quoted Copi and Cohen in more detail, demonstrating unquivocablly that rules of inference in deduction can be (and must be, if they are valid) reworded into tautologies, completely refuting our friend.
Let's see if he has the intellectual honesty to concede his blunder.
I thought the idea of feminist mathematicians was hilarious. I stole it from Alan Sokal's hoax on deconstructionism...which has a lot of similarities with presuppositionalism. Actually, I'd be hard pressed to name a difference.
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Offline I thought the idea of feminist mathematicians was hilarious. I stole it from Alan Sokal's hoax on deconstructionism...which has a lot of similarities with presuppositionalism. Actually, I'd be hard pressed to name a difference.
Man, do I agree. And what I find even more humorous is how post modernists and fundamentalists have become strangebedfellows....
*********
I was forced to take a philosophy and systems class in grad school, even though I should have been able to waive the course based on prior experience (the professor was a post modernist with a personal grudge).... He finally agreed that I could waive the class after attending 3 classes, but I offered to write a paper for the class anyway.
So I wrote on the Sokal affair just to razz him.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline It's a shame that something as absurd as deconstructionism got as far as it did on college campuses...and into the minds of the religious.
I intend to spend some more time on your site and make somments if I think of any.
I may actually start my first thread on philosophical problems that I think about. So often, arguing with religious people is at best a refresher course for onesself on the basics. What about beyond the basics? What about, "God is dead, now what?" This is what I want to get into.
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Offline It's a shame that something as absurd as deconstructionism got as far as it did on college campuses...and into the minds of the religious.
I think deconstructionism has its merits, but what I find meritous in it, actually preceded it.... every key element of deconstructionism can be traced back to the pragmatists.
I intend to spend some more time on your site and make some comments if I think of any.
Sounds good! I want to do a revamp, both format and content. Right now, it covers the basics of classical logic, propositional logic, etc.
And again, I want a better way to present the formal fallacies. More and more, a wiki presentation seems a good idea, as it would allow for user contributions.
I may actually start my first thread on philosophical problems that I think about. So often, arguing with religious people is at best a refresher course for onesself on the basics. What about beyond the basics? What about, "God is dead, now what?" This is what I want to get into.
Very nice idea. Yes, the value of these exchanges is that it allows us to go over the basics....
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Chaoslord brought up some good topics in the Philosophy forum, like the Ontology of Mathematics, and fatalism.
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Offline Chaoslord brought up some good topics in the Philosophy forum, like the Ontology of Mathematics, and fatalism.
Very nice. As you can see above, I posted Copi and Cohen in more detail for our friend, to once and for all prove that deductions can be reworded as tautologies. By the way, the site was for middle school children....
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline [(p É q). (q É r)] É (pÉ r) is a tautology.
I will now eat my word and...post.
This is something worthy of refuting. Thank you. Might I ask that next time we avoid much ado about nothing and you quote the book first.
We are not the first to discuss this.
http://www.iidb.org/vbb/showthread.php?t=65067Select quote from Theophilus:
The problem here, as you've pointed out, is if we previously know 1 and 2, then 3 is trivial and uninformative.
Bingo. If logic is tautological, the use of it is useless. If logic is not tautological, then it is not self-attesting.
So if you ever use deductive logic, you are either proving nothing, or you are assuming that logic is not self-attesting despite saying otherwise.
TAG in a nutshell.
"Truth is the cry of all, but the game of the few." George Berkeley
"Truth is always strange — stranger than fiction." Lord Byron
Fixing the world, one dumb idea at a time.
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Offline Quote:[(p É q). (q É r)] É (pÉ r) is a tautology.I will now eat my word and...post.
Thank you. Kudos to you, people rarely return and concede the issue.
This is something worthy of refuting. Thank you. Might I ask that next time we avoid much ado about nothing and you quote the book first.
You could avoid much ado about nothing by reading a logic book first, before trying to debate an issue concerning logic. I warned you about this in another thread.
You might also want to look back and see where I had already made the very same points to you earlier on page three of this thread, after which you posted two posts denying that there were any proofs presented to you.
Finally, these are basic points of deductive logic. In order to argue points of deductive logic, you really ought to know what deductive logic is first. The site I cited was for middle school students.
A summer program and resource for middle school students howing high promise in mathematics
http://www.iidb.org/vbb/showthread.php?t=65067Select quote from Theophilus:
Theophilus? Do yourself a favor and actually learn logic from someone who knows about logic.
Read the responses to his post. Pay attention to people like Witt. Even better, read Copi and Cohen. My website includes my notes from reading their text.
Bingo. If logic is tautological, the use of it is useless.
Is math useless?
You've already conceded one error in basic logic, why are you looking to leap into another? You're confusing the fact that deductions provide no inductive utility with complete uselessness: that's an error.
So if you ever use deductive logic, you are either proving nothing
Well, if you stopped to think this over, you'd realize that a deductive argument was just used to demonstrate that deductions CAN be reworded into tautologies, which led to your concession that began your post! So you've just contradicted yourself here.
Deductions allows us to prove that one entity belongs to one category or another, or you are demonstrating an equivalency. Deductions are for demonstrations. If you want to deal with rea lworld entities, then you must rely on induction. If you want to produce new information, you must rely on abduction (putatively).
Do me a favor, pick up a copy of Copi and Cohen, OK?
TAG in a nutshell.
TAG is a basic misunderstanding of deduction? I'm ready to believe that...
However, you've not given a TAG here.
I've never met a TAGer that knew much about logic... learn logic and learn just how bad an argument TAG is... do yourself this favor....
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline I think deconstructionism has its merits, but what I find meritous in it, actually preceded it.... every key element of deconstructionism can be traced back to the pragmatists.
Where it goes crazy is with the idea that EVERYTHING is text (In the beginning was the word...).
One of the best uses I've seen for it was by an author. Since it speaks so much to what can and cannot be had in text, it can be useful for authors, authors OF FICTION.
Back to the thread, keep us posted on what Kelly's up to.
Thanks Strafio for the suggestion. I'll take a look. I hinted that I have my own issues that I'm thinking about and of course thjey may be of no significant interest to anyone else.
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Offline Philosophers thrive on irrelevent problems.
Post it in the Philosophy forum.
There's a chance that it won't get answered but the worst case scenario is only five mins of tying that you won't get back. 
Bingo. If logic is tautological, the use of it is useless. If logic is not tautological, then it is not self-attesting.So if you ever use deductive logic, you are either proving nothing, or you are assuming that logic is not self-attesting despite saying otherwise.
Identities aren't 'nothing'.
For instance, we prove a complex identity like 42 x 52 = 384 by using simpler identities e.g.
42 x 52 = 50 x 2 + 40 x 2 + 50 x 40 + 2 x 2 = 100 + 80 + 4 + 200 = 384
To deny that proving that a statement is a tautology is significant is, as Tod said, to declare that all of mathematics is insignificant. Anyway, didn't you read my bit on how a reductive proof works?
I'll post it again for you:
Aristotle's syllogisms are over 2300 years old and are getting on a bit. They are only capable of simple two premise deductions. Modern Predicate logic allows for much more complex deductions and, in my opinion, is a lot easier and more intuitive to work with. The way they will prove that a conclusion follows from the premises is with algorithms like the tree method.
The method first shows that the premises and the negation of the conclusion contradict each other. If so, the deduction is valid and the following apply:
By the law of non-contradiction: the premises and negated conclusion cannot both be true - one of them must be false.
By the law of the excluded middle: If the negated conclusion isn't true then the conclusion must be true.
So we end up with the following:
If the premises are true then the negation of the conclusion must be false and that means that the conclusion itself must be true.The rules of logical deduction are constructed out of the law of non-contradiction and the law of the excluded middle. In turn, both of those laws are required by the meaning of our language.
A deductions proves that a person who affirms the premises by denies the conclusion contradicts themselves. Contradictions and identities might seem obvious in simple cases, but in more complex cases (say, when there are 100 propositions in the premises) they are more difficult to spot and more sophisticated methods are required.
This is the third time I've posted this and you are yet to respond to it. If you ignore it again then it'll confirm what we suspect - that you are not really reading what we say and are just looking for irrelevent points to nitpick.
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Offline Todangst has proven that a deductive syllogism is true, granted that the premises are accurate and that there is a logical connection.
So, granted accuracy, deductive syllogisms are true by definition. If that is what you mean by a "tautology" then you are absolutely correct.
But "true by definition" is not a tautology according to the dictionary.
Webster's New World College Dictionary Deduction: (n) Logic The process of deducing, reasoning from the general to the specific, or from premises to a logically valid conclusion. Tautology: (n) Needless repitition of an idea, redundancy.
So while all tautologies and all deductions both fall into the category of necessarily true, it does not follow that a tautology is the same as a deduction.
If you disagree, feel free to take it up with Webster.
"Truth is the cry of all, but the game of the few." George Berkeley
"Truth is always strange — stranger than fiction." Lord Byron
Fixing the world, one dumb idea at a time.
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Offline A layman's dictionary over all the books on logic that have been ever written?
Anyway, bickering over the meaning of tautology is getting us nowhere. The whole point was to ask why logical deductions work. In my post above I showed that to deny a valid deduction is to be contradictory. I've also shown that the law of non-contradiction is necessary by the meanings of words in our language. So as long as someone reasons in language, the rules of logic will apply.
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Offline You heard it here first...to settle arguments about complex philisophical questions, resort to Websters new world college dictionary and poach two line definitions. rest your argument here, and demand that your opponent refute the dictionary.
This should clear up any argument you should have. :-}
And once again, this guy misrepresents the arguments in this thread...now he is saying that a tautology is not the same as a deduction.
That was never the point. The point was that a deduction can be rewritten into a tautology.
This type of game playing makes it almost impossible to have constructive conversation.
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Offline Todangst has proven that a deductive syllogism is true, granted that the premises are accurate and that there is a logical connection.
I've done more than that, I've demonstrated that for a deductive argument to be valid, it must be capable of being reworded as a tautology.
Webster's New World College DictionaryQuote:Tautology: (n) Needless repitition of an idea, redundancy.Sigh.
Quote:If you disagree, feel free to take it up with Webster.
Actually, we need to take up your error with you.
I've already provided a DEDUCTIVE PROOF that a deductive argument can be reworded as a tautology! Citing the dictionary is simply obtuse, as dictionaries do not exist to provide rigorous philosphical defenses of the terms they list, they exist to simply provide the various uses of a word people create.
So there's no need to take it up with Webster. We can take your latest error up with you. A fallacy of equivocation.
It is an error to cite a dictionary definition that is out of context. This is the fallacy of equivocation.
Let me explain:
Will it surprise you to find out that dictionaries exist to provide definitions that people might use? I hope not.
Will it surprise you to find out that not all of these definitions are appropriate for every context? I hope not.
Would it surprise you to find out that logical and philosophical terms have colloquial usages? And that dictionaries list these definitions, sometimes along with the proper definitions, and even, in some cases, in lieu of the proper definition?
Well, here's what you should know if you're going to cite a dictionary in a discussion on logic: Dictionaries exist to provide all the popular definitions that exist for a word. If people use the word 'atheist' to mean 'satanic' or evil, then a dictionary might list that meaning. If people use 'atheist' to mean 'strong atheist' then a dictionary might list that meaning.
Dictionaries might even list the actual meaning of the 'atheist' or 'agnostic'. But one thing that dictionaries usually do not do is provide a rigorous philosophical justification for every definition listed. And that's just one reason why citing a dictionary in a theological or philosophical conversation is a basic blunder - first, you're not providing a source that actually provides a philosophical justification for the defintion, they are merely citing 'common usage!" And second, i's likely that you're importing a non philosophicall usage of the word into a philosophical debate.
And that's a fallacy of equivocation, a fallacy just as silly as thinking that you could jack up your car with a Jack of Hearts.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
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Offline Todangst has proven that a deductive syllogism is true, granted that the premises are accurate and that there is a logical connection. So, granted accuracy, deductive syllogisms are true by definition. If that is what you mean by a "tautology" then you are absolutely correct. But "true by definition" is not a tautology according to the dictionary. Webster's New World College Dictionary Deduction: (n) Logic The process of deducing, reasoning from the general to the specific, or from premises to a logically valid conclusion. So while all tautologies and all deductions both fall into the category of necessarily true, it does not follow that a tautology is the same as a deduction. If you disagree, feel free to take it up with Webster.
Tautology: (n) Needless repitition of an idea, redundancy.
It's worth pointing out now that there is a difference between the technical usage of tautology and the fallacy of circular reasoning. This is the distinction that the dictionary fails to make.
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Um...you are not allowed to criticize presuppositions since you are apparently of the opinion that the statement "logic is without foundation" is "true."
Oh, kmisho...
Don't you know that only Sir Valiant's presuppositions are the correct ones?
After all, he claims that logic can't be used to prove or disprove god but has no problem applying a logical standard (rational) to his God.
"I do this real moron thing, and it's called thinking. And apparently I'm not a very good American because I like to form my own opinions."
— George Carlin
The problem here is that Todangst and Strafio have made an assertion that all deductive arguments can be reduced to tautologies, but when asked to actually do so to just one argument (much less use induction to prove that the statement applies to all deductive statements) they fail to do so.
"Truth is the cry of all, but the game of the few." George Berkeley
"Truth is always strange — stranger than fiction." Lord Byron
Fixing the world, one dumb idea at a time.
Only if you managed to not read what they wrote...
"I do this real moron thing, and it's called thinking. And apparently I'm not a very good American because I like to form my own opinions."
— George Carlin
Uh...
Maybe I'm missing something here.
presuppositions? properly justified conclusions? You mean like the presupposition that god is necessary for anything? Justified by an ad hoc assertion that sunglasses prevent people from seeing that the presupposition of a logical self-contradictory being is logical even though it defies logic?
~shrug~
Atheism isn't a lot like religion at all. Unless by "religion" you mean "not religion". --Ciarin
http://hambydammit.wordpress.com/
Books about atheism
I actually disagree with this.
Logical methods are justified by the laws of identity, non-contradiction and excluded middle. The laws follow from the meanings of our language. So my entire philosophy of logic is based on this one assumption that I don't try to justify - I understand my language. The reason why this assumption is untouchable is that you cannot attempt to refute it without assuming it yourself. Try reasoning without language!
That's still not all the possibilities. A tautology is a statement that is true regardless of all the empirical facts. It is the negation of a contradiction. The statement; '(I am gay and not gay) is not true' is another example of a tautology.
Let's see my tautology again:
Either 'the box will burn' or ('cardboard burns well' & 'the box I put into the fire is cardboard') is not true.
The syllogism is re-written as:
Either the conclusion is true or the conjunction of the premises is false.
The point of the syllogism is to show that if the premises are true then the conclusion must be true so if the conclusion is false then the premises must be false.
Not quite... I knew better than to do that because the tautology 'cardboard burns or doesn't burn' was absolutely irrelevent to the syllogism I was trying to re-write.
I'll tell you what my problem is.
My statement was that "cardboard burns"?
When did I make that statement?
My tautology was this:
Either 'the box will burn' or ('cardboard burns well' & 'the box I put into the fire is cardboard') is not true.
How the hell is that supposed to be equivalent to "cardboard burns"?
Yes, cardboard burns is not a tautology. It is a categorical statement. But as I made no claims that it was a tautology I don't see why you brought it up. Is it that you couldn't find any real flaws in post so you made some up to attack?
I cannot believe that you are saying this.
When I presented my tautology to you you did three things:
1) You claimed that the minor premise wasn't included when it clearly was.
2) You claimed that tautologies could only be identities.
3) You ignored the syllogism that I wrote, replaced it with a categorical statement and started going on about how this categorical statement wasn't a tautology.Now fair enough, we all miss things and make mistakes in our arguments, but it's a bit rich to go and then accuse me of dodging the issue. To try and make things clearer, I'll try and re-write the tautology in another form:
The conjunction of 'The box won't burn' and 'the box is cardboard' and 'cardboard burns' is a false one.
This is a tautology because it is the negation of a contradiction.
How does this tautology relate to the syllogism?
It shows that the conjunction of the premises and the negation of the conclusion is false. This means that either the premises must be false or the negation of the conclusion must be false. If the negation of the conclusion is false then the conclusion is true. And that's what the syllogism is supposed to prove.
In predicate logic, that deals with more complex inferences than the classical syllogisms can manage, we use methods that show that the conjunction of the premises contradict the negation of the conclusion. This is how the tree method works.
Some highlights of SVT's performance on this thread so far, for those of you scoring at home. First up, his admission that he doesn't really understand any of the arguments and only parrots material that comes from sources that he trusts:
Next, he reveals that he is incapable of understanding Strafio and Todangst's arguments:
Finally, he resorts to lying:
Logic does not require all the fancy metaphysical underpinnings you are insisting it have, SVT. All logic is is a standard for checking information that we receive from others - in other words, a spin-off of language, as Strafio has said. This is obviously a useful function for a social animal to have. Primitive humans with the ability to check information from their environment and their fellow humans for internal contradictions would have gained an obvious evolutionary advantage. They would be less gullible, and more likely to notice and investigate odd phenomena, for instance. Individuals and tribes that developed flawed standards of logic would not realize these advantages and be less successful. So we can suspect that logic is probably closely tied to the real nature of physical reality, but it isn't necessarily so. After all, we might all be brains in vats, right? At the end of the day, all we know about logic is that appears to serve a number of useful cognitive purposes that appear to increase our ability to reason and thereby survive. Based on that alone, I figure it's worth using.
At any rate, if you presume that God is necessary for logic, you run into the problem of evil. Why would God equip Adam and Eve with a system for critically evaluating their environment if he wanted them to stay in a state of holy innocence?
Lazy is a word we use when someone isn't doing what we want them to do.
- Dr. Joy Brown
In the end, I am not surprised that people who have a redundancy as a basis of their philosophy (PREsupposition) have problems with logic.
LOL..... To me what's most pathetic is there absolute refusal to pick up a logic textbook and learn logic.
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'
Identities aren't the only form of tautology.
A statement of the form "P or ¬P" is a tautology.
It's basically the negation of a contradiction.
That's the kind of tautology I re-wrote your syllogism into.
Your 'fallacy of composition' claim depended on the two misunderstandings and a complete rewriting of my tautology into the completely different sentence 'cardboard = thing that burns'.
You were supposed to be finding flaws with what I wrote, not making up something new to refute!
Let me get this straight Strafio: now he doesn't even know what a tautology is?
"Hitler burned people like Anne Frank, for that we call him evil.
"God" burns Anne Frank eternally. For that, theists call him 'good.'