Does a false proposition imply every proposition ?
Eukie_M_SHIRAISHI
proposition.
However, it is very clear that their view above is totally mistaken.
Take for example, "The surface of the Earth is a triangle", whichi
is
a falsity. It does imply "The surface of the Earth is not a rectangle"
but it does not imply "The surface of the Earth is round".
The truth is that not a falsity but an absurdity (or a contradiction)
implies every proposition in the same discourse universe.
See <http://www.age.ne.jp/x/eurms/PNG/Key/Honron-3.html#02-3>
karl
> Fregeans have had maintained that a false proposition implies every
> proposition.
>
>
different?
Ciao
Karl
bluedevil.knight
> Fregeans have had maintained that a false proposition implies every
> proposition.
No, they hadn't. A contradiction implies every proposition. And this
isn't specific to Frege, but to propositional logic generally.
Eukie_M_SHIRAISHI
karl wrote:
> Eukie_M_SHIRAISHI schrieb:
> > Fregeans have had maintained that a false proposition implies every
> > proposition.
Thank you for your following. m(_ _)m
> >
> >
> Is a Fregean something like a Cantorian or in which sense are they
> different?
See the last part of <http://www.age.ne.jp/x/eurms/PNG/Key/
Honron-1.html#02-1>
The logical theory originated by Frege got "standered" in the 20th
century.
The Fregeans are defined to mean the followers of the "standered"
theory of
logic in the 20th century.
Salute
Eukie_M_SHIRAISHI
bluedevil.knight wrote:
> On Apr 12, 12:56 am, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> > Fregeans have had maintained that a false proposition implies every
> > proposition.
>
> No, they hadn't.
You are wrong.
According to the Fregeans, "P (materially) implies Q" is defined to
mean "not-P or Q".
Therefore, according to the Fregeans, a false proposition implies
every proposition,
which is utterly mistaken..
Anyway, thank you for your following. m(_ _)m
Regards
Tonico
**********************************************************
If P has a False value and Q has ANY truth value (true or false),
then P --> Q has a value of true...what bothers you so much with
that?
And don't link me to your site: I've already looked around there and
found nothing really interesting.
You seem to believe that to define "value of P --> Q is T whenever
value of P is F, no matter what Q is" is wrong...ok, do you have
anything better?
I, for one, agree pretty simply that "if the surface of the Earth is a
triangle, then cows dance cha-cha-cha with chickens in Kansas City".
What's wrong with this implication?
I'm afraid you're confusing big time between true "in the real
world" (whatever that may mean) and valid inferences in logic.
Anyway, if you have something better please do present it...
Regards
Tonio
Ross A. Finlayson
How about, "if a particular as-of-yet undecided Goldbach conjecture is
true, cows and chickens ...."
The second is conditionally true or false given the truth of whether
that Goldbach conjecture is a theorem.
What's wrong with that implication is that cows and chickens don't do
that (assuming they don't). So, not q => not p decides said Goldbach
conjecture (negatively) in a fallacious way.
There's the "if" conditional, "if p then q", which while formally might
be the same as "p => q", that's in a non-temporal setting. It seems
kind of like the difference between the complete and potential.
As well, where both of the clauses are incompatible with everything else
that is accepted true, with no reason in a vacuum, the statement isn't
vacuously true, where other statements that are actually about vacuity,
might so be. That's about statements like "the empty set contains the
set of all sets" being vacuously true or a "valid inference" and so on.
Now "if the surface of the Earth is a triangle then it has three sides",
that is less unreasonable as a valid inference, i.e. deduction.
>
> I'm afraid you're confusing big time between true "in the real
> world" (whatever that may mean) and valid inferences in logic.
>
> Anyway, if you have something better please do present it...
>
> Regards
> Tonio
There's no direct connective between triangle Earth and cha-cha-chickens
upon which inference would follow that one implies the other.
http://en.wikipedia.org/wiki/Logical_connective
http://en.wikipedia.org/wiki/Inference
Consider the three types of reasoning described as describing inference:
deductive, abductive, or inductive reasoning, none of those give p =>
q for false, and unrelated, p and q.
From two contradictory propositions, a contradictory proposition can be
described, p ^ ~p. Given a "false" proposition noncontradictory to any
other propositions, someone else might have a different opinion, but
there can't by itself be a contradiction shown, inherent in the falsity
of the proposition, because that very appelation ascribes to some
contradictory proposition truth.
Now, the consideration that either p, or not p, and not both, is called
the "law of excluded middle", or LEM, and is a principle generally held
throughout Western logic. It's like in comparing apples and oranges, an
object is an apple, or it's not. Now, that's not the same thing as the
law of conservation of truth, that for each true statement there's an
equal and opposite true statement.
Ross
Eukie_M_SHIRAISHI
Tonico wrote:
> On Apr 12, 10:33�am, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> > bluedevil.knight wrote:
> > > On Apr 12, 12:56 am, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> > > > Fregeans have had maintained that a false proposition implies every
> > > > proposition.
> >
> > > No, they hadn't.
> >
> > You are wrong.
> >
> > According to the Fregeans, �"P (materially) implies Q" is defined to
> > mean "not-P or Q".
> >
> > Therefore, according to the Fregeans, a false proposition implies
> > every proposition,
> > which is utterly mistaken..
> >
Do you want to stay on the false view of the Fregeans ?
> > Anyway, thank you for your following. �m(_ _)m
> >
> > Regards
>
> **********************************************************
>
> If P has a False value and Q has ANY truth value (true or false),
> then P --> Q has a value of true...what bothers you so much with
> that?
> And don't link me to your site: I've already looked around there and
> found nothing really interesting.
>
> You seem to believe that to define "value of P --> Q is T whenever
> value of P is F, no matter what Q is" is wrong...ok, do you have
> anything better?
> I, for one, agree pretty simply that "if the surface of the Earth is a
> triangle, then cows dance cha-cha-cha with chickens in Kansas City".
> What's wrong with this implication?
>
> I'm afraid you're confusing big time between true "in the real
> world" (whatever that may mean) and valid inferences in logic.
>
> Anyway, if you have something better please do present it...
>
> Regards
> Tonio
I suppose that you do not want to stay on the false view of the
Fregeans, do you ?
elsiemelsi
I, for one, agree pretty simply that "if the surface of the Earth is a
triangle, then cows dance cha-cha-cha with chickens in Kansas City".
What's wrong with this implication?
what is wrong is this
we could define the earth in it complexity any shape we want even a
triangle-which would mean altering what are triangles now
your behavour with chickens is not dependent on man made definitions
if it where
then
are you dancing with chickens now
as i have just defined the shape of the earth as a triangle
the earth is not round though in a mathematical sence
the earth is not any shape in a mathematical sense
mountians valleys basins all over the place make the earth no mathematical
shape
--
Message posted using http://www.talkaboutscience.com/group/sci.logic/
More information at http://www.talkaboutscience.com/faq.html
elsiemelsi
I, for one, agree pretty simply that "if the surface of the Earth is a
triangle, then cows dance cha-cha-cha with chickens in Kansas City".
What's wrong with this implication?
what is wrong is this
the physicst Wick notes “ I believe orthodox quantum theorists [slates]
reason, consciously or unconsciously, something like this. The microscopic
world exhibits paradoxes or contradictions and this fact is reflected in
the best theory describing it
so seeing reality is in a contradiction and paradox via standard logic
that means everything is possible
but i dont see cows dancing with chickens
Eukie_M_SHIRAISHI
Eukie_M_SHIRAISHI wrote:
>
> I suppose that you do not want to stay on the false view of the
> Fregeans, do you ?
We need correct logical theory in order to avoid misjudgement.
Although the Fregean Theory of Logic have had been considered
"standered" in the last century, it is found to be incorrect,.
A N Niel
<7b76e08b-8ee4-4eca...@y18g2000pre.googlegroups.com>,
Eukie_M_SHIRAISHI <ms.e...@gmail.com> wrote:
> a false proposition implies every proposition.
For "material implication", yes. For some other type of implication,
no one knows until you specify it.
It seems you fall in the "many people" section of this...
http://www.earlham.edu/~peters/courses/log/mat-imp.htm
> The logical theory originated by Frege
Perhaps better attributed to Aristotle.
Tonico
***********************************************************
If about logic we're talking about, then be clear: so far ONLY YOU
have found that something is incorrect in your own opinion, which so
far hasn't affected at all the foundations of mathematics, at least
not that I know of.
Your supposition is irrelevant, biased, unbased and illogical: you
ALREADY decided that something's wrong, so when you ask whether I, or
anyone else, wants to remain on that view you're being a stupid and
illogical patronizing troll.
Ok, enjoy your world...by the way, would you want to buy a bridge?
Kisses
Tonio
karl
>> Is a Fregean something like a Cantorian or in which sense are they
>> different?
>
>
> See the last part of <http://www.age.ne.jp/x/eurms/PNG/Key/
> Honron-1.html#02-1>
>
> The logical theory originated by Frege got "standered" in the 20th
> century.
>
> The Fregeans are defined to mean the followers of the "standered"
> theory of
> logic in the 20th century.
>
> Salute
Sorry, that does not answer my question. What is the difference
between Fregeans and Cantorians?
Second, I can't find the word "standered" in my dictionary search.
What does it mean?
Ciao
Karl
jesko
A propositional variable with false value assigned implies both true
and false.
Perhaps it is this the sense in which Frege meant that!
Es. A --> B
if A == 0 then B==1 or B==0
Arturo Magidin
> You are wrong.
>
> According to the Fregeans, "P (materially) implies Q" is defined to
> mean "not-P or Q".
>
> Therefore, according to the Fregeans, a false proposition implies
> every proposition,
Actually, assuming without granting your premise, what would correctly
follow is that "according to the Fregeans, a false proposition
(materially) implies any proposition". If you replace the technical
"(materially) implies" with "implies", you are either commiting a bait-
n-switch fallacy, or are mistaken.
Arturo Magidin sans .sig
herbzet
Eukie_M_SHIRAISHI wrote:
>
> Fregeans have had maintained that a false proposition implies every
> proposition.
>
> However, it is very clear that their view above is totally mistaken.
There are two mistakes:
1) The view above is mistaken.
2) It is a mistake to attribute the above false view to Fregeans.
> Take for example, "The surface of the Earth is a triangle", whichi
> is
> a falsity. It does imply "The surface of the Earth is not a rectangle"
Correct -- therefore, false propositions can imply other propositions.
> but it does not imply "The surface of the Earth is round".
Correct -- false propositions do not imply every proposition.
> The truth is that not a falsity but an absurdity (or a contradiction)
> implies every proposition in the same discourse universe.
This is the correct statement of the Fregean position, which is
widely misunderstood.
Good job in stating it correctly.
> See <http://www.age.ne.jp/x/eurms/PNG/Key/Honron-3.html#02-3>
--
hz
herbzet
Perhaps he means "standard" or "standardized".
> Ciao
>
> Karl
herbzet
Eukie_M_SHIRAISHI wrote:
>
> bluedevil.knight wrote:
> > On Apr 12, 12:56 am, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> > > Fregeans have had maintained that a false proposition implies every
> > > proposition.
> >
> > No, they hadn't.
>
> You are wrong.
>
> According to the Fregeans, "P (materially) implies Q" is defined to
> mean "not-P or Q".
Correct.
> Therefore, according to the Fregeans, a false proposition implies
> every proposition,
> which is utterly mistaken..
No, a false proposition therefore _materially_ implies every proposition.
Also, a true proposition is _materially_ implied by every proposition.
> Anyway, thank you for your following. m(_ _)m
>
> Regards
--
hz
herbzet
It's invalid. The antecedent does not imply the consequent.
The antecedent merely materially implies the consequent.
Material implication is not implication -- it is mis-named.
> I'm afraid you're confusing big time between true "in the real
> world" (whatever that may mean) and valid inferences in logic.
No, you are. What M. Shiraishi is confused about is what is
a correct explication of Fregean doctrine. He understands
what a valid inference is.
> Anyway, if you have something better please do present it...
http://en.wikipedia.org/wiki/Logical_implication
--
hz
herbzet
Clueless.
--
hz
herbzet
A N Niel wrote:
>
> In article
> <7b76e08b-8ee4-4eca...@y18g2000pre.googlegroups.com>,
> Eukie_M_SHIRAISHI <ms.e...@gmail.com> wrote:
>
> > a false proposition implies every proposition.
>
> For "material implication", yes. For some other type of implication,
> no one knows until you specify it.
>
> It seems you fall in the "many people" section of this...
> http://www.earlham.edu/~peters/courses/log/mat-imp.htm
No, M. Shiraishi rejects the notion of material-implication-as-implication.
As he should.
He is mistaken in attributing that notion to "Fregeans".
The essay by Peter Suber that you cite is, unfortunately, quite
unclear on the distinction between implication and material
implication. This is a very common failing of introductory
logic texts.
See http://www.cs.cornell.edu/Info/People/gries/symposium/clarke.htm
> > The logical theory originated by Frege
>
> Perhaps better attributed to Aristotle.
You and the OP are talking about two different things.
--
hz
herbzet
jesko wrote:
>
> On 12 Apr, 06:56, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> > Fregeans have had maintained that a false proposition implies every
> > proposition.
> >
> > However, it is very clear that their view above is totally mistaken.
> > Take for example, "The surface of the Earth is a triangle", whichi
> > is
> > a falsity. It does imply "The surface of the Earth is not a rectangle"
> > but it does not imply "The surface of the Earth is round".
> >
> > The truth is that not a falsity but an absurdity (or a contradiction)
> > implies every proposition in the same discourse universe.
> >
> > See <http://www.age.ne.jp/x/eurms/PNG/Key/Honron-3.html#02-3>
>
> A propositional variable with false value assigned implies both true
> and false.
No: a propositional variable with false value assigned _materially_
implies both true and false.
A false proposition will certainly imply a false proposition
(itself) and will imply any tautology. Can we always find
a contingent truth implied by an arbitrary falsehood?
Haven't thought about it.
> Perhaps it is this the sense in which Frege meant that!
>
> Es. A --> B
>
> if A == 0 then B==1 or B==0
B = 1 or B = 0 regardless of what value is assigned to A.
--
hz
Eukie_M_SHIRAISHI
> Eukie_M_SHIRAISHI schrieb:
>
> >> Is a Fregean something like a Cantorian or in which sense are they
> >> different?
>
> > See the last part of <http://www.age.ne.jp/x/eurms/PNG/Key/
> > Honron-1.html#02-1>
>
> > The logical theory originated by Frege got "standered" in the 20th
> > century.
>
> > The Fregeans are defined to mean the followers of the "standered"
> > theory of
> > logic in the 20th century.
>
> > Salute
>
> Sorry, that does not answer my question. What is the difference
> between Fregeans and Cantorians?
It is a difficult question to answer.
# Fregeans are Fregeans and Cantorians are Cantorians,
Georg Cantor did not follow Frege's theory of Logic.
> I can't find the word "standered" in my dictionary search.
> What does it mean?
Sorry I've made a typing mistake. I mean "standard",
Eukie_M_SHIRAISHI
wrote:
Thank you for your following.
However, you are mistaken. The Fregeans have had defined "P implies Q"
to mean "not-P or Q" Hence, according to the Fregean Theory of Logic,
not only a contradiction but also a mere falsity implies every
proposition,
Besides, it is a false idea to devide logic into "propositional" one
and
"predicate" one.
Regards
Tonico
I'm glad you know what Mr. Shiraishi understands and what not. Now you
did NOT understand what I said: P --> Q gets a value of T if P has a
value of F, whatever (valid proposition, of course) Q is, and all this
is material implication.
You say material implication and you think only you know how to
distinguish if from "ordinary" implication, which is what, imho,
Shiraishi condused. All the time I was talking of conditional of
functional condition as in truth tables, otherwise why else I would
ask him whether he has anything (definition) better?
You wrote that "If the Earth whatever then the cows whatever
isminvalid". You're wrong. All the time I made it sure that I was
talking formally, and you, and apparently the OP as well, can't tell
the difference.
This is a mathematics group. There's a good chance most people talks
about mathematics-related stuff. It is made clear, or at least it was
made clear to me when I studied mathematical logic in in the Math.
Dept., and also when I did study logic in the Philosophy Dept, of my
university that in propositional logic we're dealing merely with
formalisms and with material implications.
About your last remark I think it is wrong: Mr Shiraishi does not
understand what a valid inference is, and it seems neither do you.
Regards
Tonio
Tonico
> jesko wrote:
>
> > On 12 Apr, 06:56, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> > > Fregeans have had maintained that a false proposition implies every
> > > proposition.
>
> > > However, it is very clear that their view above is totally mistaken.
> > > Take for example, "The surface of the Earth is a triangle", whichi
> > > is
> > > a falsity. It does imply "The surface of the Earth is not a rectangle"
> > > but it does not imply "The surface of the Earth is round".
>
> > > The truth is that not a falsity but an absurdity (or a contradiction)
> > > implies every proposition in the same discourse universe.
>
> > > See <http://www.age.ne.jp/x/eurms/PNG/Key/Honron-3.html#02-3>
>
> > A propositional variable with false value assigned implies both true
> > and false.
>
> No: a propositional variable with false value assigned _materially_
> implies both true and false.
>
Only you, Mr. Herbzet, seems to be so worried about "material" and not
material. Cut it out, sir: it is LOGIC we're talking about here, as
far as I am aware, so it is ALL material stuff that we're talking
about UNLESS someone, like Mr Shiraishi or you yourself, confuses
things.
Regards
Tonio
goanna
> "bluedevil.knight" <bluedevi...@yahoo.com>
> wrote:
> > On Apr 12, 12:56 am, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> >
> > > Fregeans have had maintained that a false proposition implies every
> > > proposition.
> >
> > No, they hadn't. A contradiction implies every proposition. And this
> > isn't specific to Frege, but to propositional logic generally.
> Thank you for your following.
> However, you are mistaken. The Fregeans have had defined "P implies Q"
> to mean "not-P or Q" Hence, according to the Fregean Theory of Logic,
> not only a contradiction but also a mere falsity implies every
> proposition,
You make an elementary mistake. A mere falsity does not imply every
proposition, just every material implication it is the antecedent of,
ie, ~P -> (P -> Q), as is obvious when rewritten as ~P -> (~P v Q).
But this says nothing about the truth of Q, only that of (~P v Q).
This is no more remarkable or surprising than the fact that a true
proposition P implies every disjunction of which it is a part,
ie, P -> (P v Q) for arbitrary Q. Again, this says nothing about Q.
What is more interesting is that a contradiction (P & ~P) does imply
every proposition, as is easily shown. Let Q be arbitrary.
1) ~P -> (~P v Q)
2) (~P v Q) -> (P -> Q)
3) (P & (P -> Q)) -> Q
So we can derive any Q, provided we have both P and ~P.
> Besides, it is a false idea to devide logic into "propositional" one
> and "predicate" one.
It's no wonder you are making such elementary mistakes.
Try learning the basics.
Muhammad
> Fregeans have had maintained that a false proposition implies every
> proposition.
>
> Take for example, "The surface of the Earth is a triangle", whichi
> is
> a falsity. It does imply "The surface of the Earth is not a rectangle"
> but it does not imply "The surface of the Earth is round".
>
> The truth is that not a falsity but an absurdity (or a contradiction)
> implies every proposition in the same discourse universe.
>
> See <http://www.age.ne.jp/x/eurms/PNG/Key/Honron-3.html#02-3>
Thank you for this nice piece of information. Now prove for the record
that the implication: P implies Q is false where P is "The surface of
the Earth is a triangle" and Q is "The surface of the Earth is a
rectangle". (God only knows where you got the idea that some folks
would still honor the idea of a flat earth.) While you are at it give
us also the truth value of: If Eukie knows good English then Muhammad
is Shakespeare. (Let me admit that I am not Shakespeare!) On my part I
claim that the following is true (on the grounds that you cannot prove
it to be false): If F -> F is false then the moon is made of blue
cheese. (Here F represents a false statement.)
Muhammad
herbzet
Tonico wrote:
>
> herbzet wrote:
> > jesko wrote:
> > > Eukie_M_SHIRAISHI wrote:
> > > > Fregeans have had maintained that a false proposition implies every
> > > > proposition.
> >
> > > > However, it is very clear that their view above is totally mistaken.
> > > > Take for example, "The surface of the Earth is a triangle", whichi
> > > > is
> > > > a falsity. It does imply "The surface of the Earth is not a rectangle"
> > > > but it does not imply "The surface of the Earth is round".
> >
> > > > The truth is that not a falsity but an absurdity (or a contradiction)
> > > > implies every proposition in the same discourse universe.
> >
> > > > See <http://www.age.ne.jp/x/eurms/PNG/Key/Honron-3.html#02-3>
> >
> > > A propositional variable with false value assigned implies both true
> > > and false.
> >
> > No: a propositional variable with false value assigned _materially_
> > implies both true and false.
> >
> ************************************************************
>
> Only you, Mr. Herbzet, seems to be so worried about "material" and not
> material. Cut it out, sir: it is LOGIC we're talking about here, as
> far as I am aware, so it is ALL material stuff that we're talking
> about UNLESS someone, like Mr Shiraishi or you yourself, confuses
> things.
See http://en.wikipedia.org/wiki/Logical_implication .
Please be sure to read to the end of the second paragraph,
where it says:
"The weaker truth function material implication, denoted by '->',
should not be confused with the stronger logical implication."
Yours truly,
hz
Eukie_M_SHIRAISHI
> Eukie_M_SHIRAISHI <ms.eu...@gmail.com> writes:
> > "bluedevil.knight" <bluedevil.kni...@yahoo.com>
> > wrote:
> > > On Apr 12, 12:56 am, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
>
> > > > Fregeans have had maintained that a false proposition implies every
> > > > proposition.
>
> > > No, they hadn't. A contradiction implies every proposition. And this
> > > isn't specific to Frege, but to propositional logic generally.
> > Thank you for your following.
> > However, you are mistaken. The Fregeans have had defined "P implies Q"
> > to mean "not-P or Q" Hence, according to the Fregean Theory of Logic,
> > not only a contradiction but also a mere falsity implies every
> > proposition,
>
> You make an elementary mistake. A mere falsity does not imply every
> proposition, just every material implication it is the antecedent of,
> ie, ~P -> (P -> Q), as is obvious when rewritten as ~P -> (~P v Q).
No ! According to FL or the Fregean Theory of Logic, "P impliers Q"
is defined to mean "not-P or Q" Hence, according to FL,
not only a contradiction but also a mere falsity implies every
proposition,
which is totally mistaken.
Regards
Tonico
******************************************
Ok, I read it....so?? Talk to Mr Shiraishi, not to me. He's been
talking all the way long about the fact that P --> Q means (is
defined, as he writes) that (as) ~P V Q.
So far no logical implication here, just material one between
conditionals.
And this is what has been pointed out, as far as I am aware, to
Shiraishi's remarks: there is no logical implication "if the Earth is
triangle shaped" ==> "the Earth is then square shaped", but there is a
material implication, meaning: if the antecedent has a truth value of
FALSE, then the whole P --> Q proposition will have a value of TRUE,
whatever the value of Q is.
How many times more will I have to repeat this?
If you want to read carefully Mr. Shiraishi's views, once again, just
read his message just below this one (No. 36, from Apr 14, at 3:42
am), in which he writes, among other things, that "not only a
contradiction but also a mere falsity implies every proposition, which
is totally mistaken.", so who's confusing stuff here?
Regards
Tonio
holde...@yahoo.ca
I don't agree. IMO, bluedevil.knight is correct.
The world is flat implies 1+1=3, is not tautologous.
Rather it is equivalent to, the world is not flat.
But, (the world is flat, and, the world is not flat) implies 1+1=3, is
tautologous.
goanna
> On 4月13日, 午後7:22, goanna <spamt...@crayne.org> wrote:
> > Eukie_M_SHIRAISHI <ms.eu...@gmail.com> writes:
> > > "bluedevil.knight" <bluedevil.kni...@yahoo.com>
> > > wrote:
> > > > On Apr 12, 12:56 am, Eukie_M_SHIRAISHI <ms.eu...@gmail.com> wrote:
> >
> > > > > Fregeans have had maintained that a false proposition implies every
> > > > > proposition.
> >
> > > > No, they hadn't. A contradiction implies every proposition. And this
> > > > isn't specific to Frege, but to propositional logic generally.
> > > Thank you for your following.
> > > However, you are mistaken. The Fregeans have had defined "P implies Q"
> > > to mean "not-P or Q" Hence, according to the Fregean Theory of Logic,
> > > not only a contradiction but also a mere falsity implies every
> > > proposition,
> >
> > You make an elementary mistake. A mere falsity does not imply every
> > proposition, just every material implication it is the antecedent of,
> > ie, ~P -> (P -> Q), as is obvious when rewritten as ~P -> (~P v Q).
> No ! According to FL or the Fregean Theory of Logic, "P impliers Q"
> is defined to mean "not-P or Q"
Correct.
> Hence, according to FL,
> not only a contradiction but also a mere falsity implies every
> proposition,
> which is totally mistaken.
Wrong, fuckwit. Learn some elementary logic, if your miserable
brain is capable of rising to the challenge.
> Regards
Plonk.
Dirk Van de moortel
480048cd$0$637$9b4e...@newsspool1.arcor-online.net
> Eukie_M_SHIRAISHI schrieb:
>> Fregeans have had maintained that a false proposition implies every
>> proposition.
>>
>>
While we're at it, let him explain the difference with an Einsteinian
as well.
Dirk Vdm
Eukie_M_SHIRAISHI
goanna wrote:
> Eukie_M_SHIRAISHI <ms.e...@gmail.com> writes:
>
> > No ! According to FL or the Fregean Theory of Logic, "P impliers Q"
> > is defined to mean "not-P or Q"
>
> Correct.
>
> > Hence, according to FL,
> > not only a contradiction but also a mere falsity implies every
> > proposition,
> > which is totally mistaken.
>
> Wrong, fuckwit. Learn some elementary logic, if your miserable
> brain is capable of rising to the challenge.
>
Thank you for your following, however, you are mistaken.
In FL "P impliers Q"is defined to mean "not-P or Q",
therefore according to FL, not only a contradiction
herbzet
Eukie_M_SHIRAISHI wrote:
> goanna wrote:
> > Eukie_M_SHIRAISHI <ms.e...@gmail.com> writes:
> >
> > > No ! According to FL or the Fregean Theory of Logic, "P impliers Q"
> > > is defined to mean "not-P or Q"
> >
> > Correct.
> >
> > > Hence, according to FL,
> > > not only a contradiction but also a mere falsity implies every
> > > proposition,
> > > which is totally mistaken.
> >
> > Wrong, fuckwit. Learn some elementary logic, if your miserable
> > brain is capable of rising to the challenge.
> >
>
> Thank you for your following, however, you are mistaken.
>
> In FL "P implies Q"is defined to mean "not-P or Q",
> therefore according to FL, not only a contradiction
> but also a mere falsity implies every proposition,
First of all, you need to define "Fregean logic". A citation
or quote from some well-known text would be in order.
Second of all, you are correct in distinguishing implication
from material implication -- congratulations on arriving at
this insight on your own. Many people, evidently, are confused
about this.
However, you are not the first to appreciate this distinction.
Please take the time to carefully read the article on logical
consequence at
http://www.iep.utm.edu/l/logcon.htm
Regards,
hz
--