Suppose I can think of a perfect pink unicorn and no better pink unicorn can be conceived via thought. It’s existence is not a necessity although it is contingent. — invicta
"There exists an x such that x is f".∃(x)f(x)
I've seen this argument before but never fully understood it. Can you provide a reference which elaborates? Why can't existence be regarded as a first-order predicate?Russell set Kant's objection out much more clearly. this is an oversimplification, but...
Existence is taken as a second-order predicate.
First-order predicates apply to (range over) individuals, and are written using the letters f,g,h... We write "f(a)" for the predication "a is f". — Banno
1. If TTWNGCBC existed contingently, then there would be something greater than it (viz. a version of TTWNGCBC that existed necessarily).
2. Nothing is greater than TTWNGCBC.
3. Therefore, TTWNGCBC exists necessarily.
4. TTWNGCBC is God.
5. Therefore, God is necessarily existent. — Epicero
1. That than which nothing greater can be conceived (TTWNGCBC) exists in thought.
2. It is greater to exist in thought and in actuality than to exist just in thought.
3. TTWNGCBC exists in actuality.
4. If TTWNGCBC exists in actuality, then God exists in actuality.
5. God exists in actuality — Epicero
because the thing conceived (as shown in brackets) in 4) is "greater" than in 3)….. — Michael
…..then 2) must be true, which again is a fallacious reinterpretation. — Michael
Why can't existence be regarded as a first-order predicate? — Art48
Here are two puzzles, from Frege and Russell, that must be explained if one is to treating "exists" as a property.
1. What is the difference between a sweet, juicy, red apple and a sweet, juicy red apple that exists? The difference between a red apple and a green apple, or a sweet apple and a sour apple, is pretty clear. But explaining clearly what is added to an apple by existing...?
2. It's not difficult to understand an apple that is not sweet, or an apple that is not red - but an apple that does not exist? What is it? — Banno
The upshot of all this is that it is pretty much impossible to set out the structure of the ontological argument in first-order logic. Or if you prefer, that the argument does not make sense.
Hence it is not valid. — Banno
1. If TTWNGCBC existed contingently, then there would be something greater than it (viz. a version of TTWNGCBC that existed necessarily).
2. Nothing is greater than TTWNGCBC.
3. Therefore, TTWNGCBC exists necessarily.
4. TTWNGCBC is God.
5. Therefore, God is necessarily existent. — Epicero
Your argument appears to be:
1. If God exists then God necessarily exists
2. Therefore, God (necessarily) exists — Michael
a) If some X is TTWNGCBC then X necessarily exists — Michael
Given 4), replace "TTWNGCBC" with "God:
b) If some X is God then X necessarily exists — Michael
No, the argument is "If some X is TTWNGCBC, then X necessarily exists". — Hallucinogen
If some X is TTWNGCBC then X necessarily exists
If some X is TTWNGCBC then X is God
If some X is God then X necessarily exists
Therefore, God (necessarily) exists
This is what the argument amounts to. The conclusion is a non sequitur. — Michael
It could go:
If some X is TTWNGCBC, then X necessarily exists
God is an X.
Therefore, God (necessarily) exists.
Not a non sequitur. — Hallucinogen
You're misunderstanding the logic. Look at existential quantification. — Michael
1. If there exists something which is TTWNGCBC then this thing necessarily exists
2. If there exists something which is TTWNGCBC then this thing is God
3. If there exists something which is God then this thing necessarily exists
4. Therefore, God (necessarily) exists — Michael
3. in the above isn't in the original argument by the OP. They don't give the condition "if there exists God..." in the argument. It isn't necessary to include and I don't see a fallacy in the argument without it. All that is necessary is stating that God fits the definition of TTWNGCBC in some way, which the OP did in point 4. — Hallucinogen
Then the argument is:
1. If there exists something which is TTWNGCBC then this thing necessarily exists
2. If there exists something which is TTWNGCBC then this thing is God
3. Therefore, God (necessarily) exists — Michael
Which again is invalid. — Michael
1. If there exists something which is TTWNGCBC then this thing necessarily exists
2. If there exists something which is TTWNGCBC then this thing is God
3. TTWNGCBC is God (or vice versa).
4. Therefore, God (necessarily) exists. — Hallucinogen
How so? — Hallucinogen
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