18767
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Free logics has terms that do not designate real things, and even empty domains [Anderson,CA]
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Full Idea:
Free logics say 1) singular terms are allowed that do not designate anything that exists; sometimes 2) is added: the domain of discourse is allowed to be empty. Logics with both conditions are called 'universally free logics'.
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From:
C. Anthony Anderson (Identity and Existence in Logic [2014], 2.3)
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A reaction:
I really like the sound of this, and aim to investigate it. Karel Lambert's writings are the starting point. Maybe the domain of logic is our concepts, rather than things in the world, in which case free logic sounds fine.
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18771
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Stop calling ∃ the 'existential' quantifier, read it as 'there is...', and range over all entities [Anderson,CA]
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Full Idea:
Ontological quantifiers might just as well range over all the entities needed for the semantics. ...The minimal way would be to just stop calling '∃' an 'existential quantifier', and always read it as 'there is...' rather than 'there exists...'.
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From:
C. Anthony Anderson (Identity and Existence in Logic [2014], 2.6)
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A reaction:
There is no right answer here, but it seems to be the strategy adopted by most logicians, and the majority of modern metaphysicians. They just allow abstracta, and even fictions, to 'exist', while not being fussy what it means. Big mistake!
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18768
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We cannot pick out a thing and deny its existence, but we can say a concept doesn't correspond [Anderson,CA]
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Full Idea:
Parmenides was correct - one cannot speak of that which is not, even to say that it is not. But one can speak of concepts and say of them that they do not correspond to anything real.
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From:
C. Anthony Anderson (Identity and Existence in Logic [2014], 2.5)
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A reaction:
[This summarises Alonso Church, who was developing Frege] This sounds like the right thing to say about non-existence, but then the same principle must apply to assertions of existence, which will also be about concepts and not things.
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18765
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Individuation was a problem for medievals, then Leibniz, then Frege, then Wittgenstein (somewhat) [Anderson,CA]
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Full Idea:
The medieval philosophers and then Leibniz were keen on finding 'principles of individuation', and the idea appears again in Frege, to be taken up in some respects by Wittgenstein.
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From:
C. Anthony Anderson (Identity and Existence in Logic [2014], 1.6)
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A reaction:
I take a rather empirical approach to this supposed problem, and suggest we break 'individuation' down into its component parts, and then just drop the word. Discussions of principles of individuations strike me as muddled. Wiggins and Lowe today.
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14381
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A statue is essentially the statue, but its lump is not essentially a statue, so statue isn't lump [Yablo, by Rocca]
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Full Idea:
Yablo proposes the argument that Statue A is essentially a statue, and Lump 1 is not essentially a statue, so Statue A is not identical with Lump 1.
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From:
report of Stephen Yablo (Identity, Essence and Indiscernibility [1987]) by Michael della Rocca - Essentialists and Essentialism I
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A reaction:
Della Rocca and Yablo unashamedly elide necessary properties with essential properties, so this argument doesn't bother me too much. It concerns the statue and the clay having different modal properties.
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18764
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The notion of 'property' is unclear for a logical version of the Identity of Indiscernibles [Anderson,CA]
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Full Idea:
In the Identity of Indiscernibles, one speaks about properties, and the notion of a property is by no means clearly fixed and formalized in modern symbolic logic.
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From:
C. Anthony Anderson (Identity and Existence in Logic [2014], 1.5)
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A reaction:
The unclarity of 'property' is a bee in my philosophical bonnet, in speech, and in metaphysics, as well as in logic. It may well be the central problem in our attempts to understand the world in general terms. He cites intensional logic as promising.
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13764
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Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington]
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Full Idea:
Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'?
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From:
Dorothy Edgington (Conditionals [2001], 17.1)
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A reaction:
I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional.
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13765
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'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington]
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Full Idea:
If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B).
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From:
Dorothy Edgington (Conditionals [2001], 17.1)
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A reaction:
This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true.
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