Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

Thanks,
S.

On Apr 14, 4:47 am, sanchopanch...@web.de wrote:

Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

Thanks,
S.

Existence is a predicate but, it is not a primary predicate such as
"having a leg".

x exists =df EF(Fx).
Gx -> x exists. If there is a primary predicate that x has, then, x
exists.

On 14 Apr., 10:54, holden_o...@yahoo.ca wrote:





On Apr 14, 4:47 am, sanchopanch...@web.de wrote:

Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

Thanks,
S.

Existence is a predicate but, it is not a primary predicate such as
"having a leg".

x exists =df EF(Fx).
Gx -> x exists. If there is a primary predicate that x has, then, x
exists.

Thanks for the answer. I would be very pleased if you give me a
reference for such things like "primary predicate".
Thanks you,
S-- Hide quoted text -

- Show quoted text -

On Mon, 14 Apr 2008 01:47:21 -0700 (PDT), sanchopanch...@web.de wrote:
Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

A predicate is supposed to divide the universe into two classes,
the things that satisfy the predicate and the things that don't.
Existence doesn't do this, because _everything_ exists!

Yes, everything exists. If you want to claim otherwise you
have to prove the existence of something that does not exist,
and that's going to be hard.

The way language is used it often sounds like it's talking about
things that do not exist, but that's just a problem with the way
language is used.

Thanks,
S.

David C. Ullrich

On Apr 14, 2:01 pm, sanchopanch...@web.de wrote:





On 14 Apr., 10:54, holden_o...@yahoo.ca wrote:

On Apr 14, 4:47 am, sanchopanch...@web.de wrote:

Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

Thanks,
S.

Existence is a predicate but, it is not a primary predicate such as
"having a leg".

x exists =df EF(Fx).
Gx -> x exists. If there is a primary predicate that x has, then, x
exists.

Thanks for the answer. I would be very pleased if you give me a
reference for such things like "primary predicate".
Thanks you,
S-- Hide quoted text -

- Show quoted text -

I'm not sure holden's definition of exists is the best. Formally,
satisfying a predicate is not enough for existing. Supose that the
second order predicate

EF (Fx)

were equivalent to the existence predicate.

Since F is any predicate, we can take F = ~EP (Px)

Then, if that characterization of existence is correct, all
nonexistent objects (such as the square circle) would satisfy F; hence
they would exist.

I think it preferable:

x exists =: Ey (y=x)

As for existence as a very special kind of predicate, I'd say the
discussion goes back at least to Kant's assessment of the ontological
argument in the KrV. If we can include existence in the essence of an
object, we can trivially prove its existence. If we can include
existence in a concept as a any other feature, such as having wings or
being rational, we could prove the existence of whatever.

E.g. take the concept of 'existent unicorn'. An existent unicorn
cannot fail to exist. And an existent unicorn is a unicorn;
consequently, unicorns exist.

Kant proposed the distinction between material (or 'real') predicates
and formal predicates, existence being a formal one. That's why modern
logic took existence to be a logical constant (a quantifier) rather
than a predicate; at most existence can be a predicate constructed
with just logical constants.

It seems clear to me that existence is not the sort of predicate that
could contribute to the definition of a concept.

Regards- Hide quoted text -

- Show quoted text -

Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

Thanks,
S.

Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

On Mon, 14 Apr 2008 10:04:31 -0700 (PDT), holden_o...@yahoo.ca wrote:
On Apr 14, 9:36 am, David C. Ullrich <dullr...@sprynet.com> wrote:
On Mon, 14 Apr 2008 01:47:21 -0700 (PDT), sanchopanch...@web.de wrote:
Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

A predicate is supposed to divide the universe into two classes,
the things that satisfy the predicate and the things that don't.
Existence doesn't do this, because _everything_ exists!

Yes, everything exists. If you want to claim otherwise you
have to prove the existence of something that does not exist,
and that's going to be hard.

The way language is used it often sounds like it's talking about
things that do not exist, but that's just a problem with the way
language is used.

Thanks,
S.

David C. Ullrich

I don't agree.

We know that.

If we allow 'things' to include described objects as well as existent
objects,
then there are non-existent things, For example the described object,
the present king of France,
does not exist.

Yes, if we allow the meaning of the word "things" to include things
which are not things then things change. There is no such thing
as the present king of France. _calling_ it "the described object"
does not change the fact that there is no such thing.

Saying that the present king of France does not exist is of course
exactly an example of what I meant when I said that the way
we use language sometimes seems to contradict the fact that
everything exists. The sentence really means that for every x,
x is not the present king of France.

There is no primary predicate (property) that is true of the present
king of France.

ie. ~EF(F(the present king of France)) means that it does not exist.

This has always seemed like one of the stranger of your assertions.
If we are going to talk about the present king of France, why do
we not say that he satisfies the predicate "is the king of a country"?

David C. Ullrich- Hide quoted text -

- Show quoted text -

On Mon, 14 Apr 2008 01:47:21 -0700 (PDT), sanchopanch...@web.de wrote:
Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

A predicate is supposed to divide the universe into two classes,
the things that satisfy the predicate and the things that don't.
Existence doesn't do this, because _everything_ exists!

On Apr 14, 9:36 am, David C. Ullrich <dullr...@sprynet.com> wrote:
On Mon, 14 Apr 2008 01:47:21 -0700 (PDT), sanchopanch...@web.de wrote:
Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

A predicate is supposed to divide the universe into two classes,
the things that satisfy the predicate and the things that don't.
Existence doesn't do this, because _everything_ exists!

Yes, everything exists. If you want to claim otherwise you
have to prove the existence of something that does not exist,
and that's going to be hard.

The way language is used it often sounds like it's talking about
things that do not exist, but that's just a problem with the way
language is used.

Thanks,
S.

David C. Ullrich

I don't agree.

If we allow 'things' to include described objects as well as existent
objects,
then there are non-existent things, For example the described object,
the present king of France,
does not exist.

There is no primary predicate (property) that is true of the present
king of France.

ie. ~EF(F(the present king of France)) means that it does not exist.

On Apr 14, 9:56 am, LauLuna <laureanol...@yahoo.es> wrote:





On Apr 14, 2:01 pm, sanchopanch...@web.de wrote:

On 14 Apr., 10:54, holden_o...@yahoo.ca wrote:

On Apr 14, 4:47 am, sanchopanch...@web.de wrote:

Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

Thanks,
S.

Existence is a predicate but, it is not a primary predicate such as
"having a leg".

x exists =df EF(Fx).
Gx -> x exists. If there is a primary predicate that x has, then, x
exists.

Thanks for the answer. I would be very pleased if you give me a
reference for such things like "primary predicate".
Thanks you,
S-- Hide quoted text -

- Show quoted text -

I'm not sure holden's definition of exists is the best. Formally,
satisfying a predicate is not enough for existing. Supose that the
second order predicate

EF (Fx)

were equivalent to the existence predicate.

Since F is any predicate, we can take F = ~EP (Px)

Then, if that characterization of existence is correct, all
nonexistent objects (such as the square circle) would satisfy F; hence
they would exist.

I said that F, G, etc. are primary predicates (properties).
Compound predicates such as ~EP(Px) are not properties (primary
predicates).



I think it preferable:

x exists =: Ey (y=x)

Within the context of FOPL x=x or Ey(x=y) or will work.
But in that case, because Ax(x=x) is an axiom, everything exists is a
theorem,
as David Ullrich said.



As for existence as a very special kind of predicate, I'd say the
discussion goes back at least to Kant's assessment of the ontological
argument in the KrV. If we can include existence in the essence of an
object, we can trivially prove its existence. If we can include
existence in a concept as a any other feature, such as having wings or
being rational, we could prove the existence of whatever.

We prove the existence of x by asserting that it has at least one
property.
If x has the property F, then x exists.

Existence is not a property of things.



E.g. take the concept of 'existent unicorn'. An existent unicorn
cannot fail to exist. And an existent unicorn is a unicorn;
consequently, unicorns exist.

Nonsense. The description 'an existent unicorn' does not exist at all.

On Apr 14, 7:44 pm, holden_o...@yahoo.ca wrote:



On Apr 14, 9:56 am, LauLuna <laureanol...@yahoo.es> wrote:

On Apr 14, 2:01 pm, sanchopanch...@web.de wrote:

On 14 Apr., 10:54, holden_o...@yahoo.ca wrote:

On Apr 14, 4:47 am, sanchopanch...@web.de wrote:

Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

Thanks,
S.

Existence is a predicate but, it is not a primary predicate such as
"having a leg".

x exists =df EF(Fx).
Gx -> x exists. If there is a primary predicate that x has, then, x
exists.

Thanks for the answer. I would be very pleased if you give me a
reference for such things like "primary predicate".
Thanks you,
S-- Hide quoted text -

- Show quoted text -

I'm not sure holden's definition of exists is the best. Formally,
satisfying a predicate is not enough for existing. Supose that the
second order predicate

EF (Fx)

were equivalent to the existence predicate.

Since F is any predicate, we can take F = ~EP (Px)

Then, if that characterization of existence is correct, all
nonexistent objects (such as the square circle) would satisfy F; hence
they would exist.

I said that F, G, etc. are primary predicates (properties).
Compound predicates such as ~EP(Px) are not properties (primary
predicates).

I think it preferable:

x exists =: Ey (y=x)

Within the context of FOPL x=x or Ey(x=y) or will work.
But in that case, because Ax(x=x) is an axiom, everything exists is a
theorem,
as David Ullrich said.

As for existence as a very special kind of predicate, I'd say the
discussion goes back at least to Kant's assessment of the ontological
argument in the KrV. If we can include existence in the essence of an
object, we can trivially prove its existence. If we can include
existence in a concept as a any other feature, such as having wings or
being rational, we could prove the existence of whatever.

We prove the existence of x by asserting that it has at least one
property.
If x has the property F, then x exists.

We can prove nothing by simply asserting. But I repeat, representing
existence by predicate possession is inconsistent unless there are a
clear definition of what predicates serve for the prurpose and what
not. For example, you suggest the predicate 'x=x' does not do the job
either.

On Tue, 15 Apr 2008 07:04:11 -0700 (PDT), holden_o...@yahoo.ca wrote:
On Apr 15, 7:34 am, David C. Ullrich <dullr...@sprynet.com> wrote:
On Mon, 14 Apr 2008 10:04:31 -0700 (PDT), holden_o...@yahoo.ca wrote:
On Apr 14, 9:36 am, David C. Ullrich <dullr...@sprynet.com> wrote:
On Mon, 14 Apr 2008 01:47:21 -0700 (PDT), sanchopanch...@web.de wrote:
Hello,

I have read somewhere that "existence" wouldn't be a predicate in the
way e.g. "having a leg" is a predicate. Does anyone have a good and
actual reference on that or liks me to tell why?

A predicate is supposed to divide the universe into two classes,
the things that satisfy the predicate and the things that don't.
Existence doesn't do this, because _everything_ exists!

Yes, everything exists. If you want to claim otherwise you
have to prove the existence of something that does not exist,
and that's going to be hard.

The way language is used it often sounds like it's talking about
things that do not exist, but that's just a problem with the way
language is used.

Thanks,
S.

David C. Ullrich

I don't agree.

We know that.

If we allow 'things' to include described objects as well as existent
objects,
then there are non-existent things, For example the described object,
the present king of France,
does not exist.

Yes, if we allow the meaning of the word "things" to include things
which are not things then things change. There is no such thing
as the present king of France. _calling_ it "the described object"
does not change the fact that there is no such thing.

The description 'the present king of France' does exist, but it does
not have a referent.
It has sense but no reference.

Of course the description exists! That has no bearing on the
question of whether everything exists - the description does
in fact exist.

I didn't say that the description didn't exist. And I didn't
say that the description does not "have sense". What
I said was that there's no such thing as the present
king of France. There isn't. So it's not a counterexample
to my assertion that everything exists.

Saying that the present king of France does not exist is of course
exactly an example of what I meant when I said that the way
we use language sometimes seems to contradict the fact that
everything exists. The sentence really means that for every x,
x is not the present king of France.

Yes, ~Ex(x = (the present king of France)) is true,

as is ~((the
present king of France)=(the present king of France)).

There is no primary predicate (property) that is true of the present
king of France.

ie. ~EF(F(the present king of France)) means that it does not exist.

This has always seemed like one of the stranger of your assertions.
If we are going to talk about the present king of France, why do
we not say that he satisfies the predicate "is the king of a country"?

Because it is clearly false.
(the present king of France) is a king, is false.
(the present king of France) is present, is false.
(the present king of France) is a Frenchman, is false.
(the present king of France) has existence, is false.
(the present king of France) has non-existence, is false.

There is no property that (the present king of France) has.

Proof:
F(the present king of France) <-> Ey(Ax(x=y <-> x is a present king of
France) & Fy)
F(the present king of France) <-> Ey(Ax(x=y <-> (x is a present king
of France & there is no present king of France) & Fy)
(x is a present king of France & there is no present king of France),
is a contradiction.
F(the present king of France) <-> Ey(Ax(x=y <-> contradiction) & Fy).
But, Ax(x=y <-> contradiction) <-> ~Ex(x=y).
But, Ex(x=y) is a theorem.
therefore,
F(the present king of France) <-> contradiction.
ie. ~(F(the present king of France)), for all F.

~EF(F(the present king of France), is a theorem.
There is no property that the present king of France has. ie. it does
not exist.

~(Fx) <-> (~F)x, iff, x exists.

ie. ~(F(the present king of France)) <-> (~F)(the present king of
France), is false.

(the present king of France) has existence. or (the present king of
France) has non-existence. ..is a contradiction.
(the present king of France) has existence. or ~((the present king of
France) has existence). ..is a tautology.

David C. Ullrich- Hide quoted text -

- Show quoted text -

David C. Ullrich- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -