Combining Texts

All the ideas for 'Leibniz', 'Intensions Revisited' and 'Identity through Possible Worlds'

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9 ideas

4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
Quantified modal logic collapses if essence is withdrawn [Quine]
     Full Idea: The whole of quantified modal logic collapses if essence is withdrawn.
     From: Willard Quine (Intensions Revisited [1977], p.121)
     A reaction: Quine offers an interesting qualification to this crushing remark in Idea 13590. The point is that objects must retain their identity in modal contexts, as if I say 'John Kennedy might have been Richard Nixon'. What could that mean?
9. Objects / D. Essence of Objects / 14. Knowledge of Essences
If there are essential properties, how do you find out what they are? [Chisholm]
     Full Idea: It seems to me that if Adam does have essential properties, there is no procedure at all for finding out what they are.
     From: Roderick Chisholm (Identity through Possible Worlds [1967], p.85)
     A reaction: My tentative suggestion is that the essential properties are those which explain the nature, power, function and role of Adam in the 'actual' world. Whatever possibilities he acquires, he had better retain the capacity to be the First Man.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Essences can make sense in a particular context or enquiry, as the most basic predicates [Quine]
     Full Idea: The notion of essence makes sense in context. Relative to a particular enquiry, some predicates may play a more basic role than others, or may apply more fixedly; and these may be treated as essential.
     From: Willard Quine (Intensions Revisited [1977], p.121)
     A reaction: Quine has got a bad press on essentialism, and on modal logic, but I take this point seriously. If you give something a fixed identity by means of essence in some context, you can then go ahead and apply possible world reasoning in that context.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Identity of Indiscernibles is really the same as the verification principle [Jolley]
     Full Idea: Various writers have noted that the Identity of Indiscernibles is really tantamount to the verification principle.
     From: Nicholas Jolley (Leibniz [2005], Ch.3)
     A reaction: Both principles are false, because they are the classic confusion of epistemology and ontology. The fact that you cannot 'discern' a difference between two things doesn't mean that there is no difference. Things beyond verification can still be discussed.
10. Modality / A. Necessity / 11. Denial of Necessity
Necessity is relative to context; it is what is assumed in an inquiry [Quine]
     Full Idea: The very notion of necessity makes sense to me only relative to context. Typically it is applied to what is assumed in an inquiry, as against what has yet to transpire.
     From: Willard Quine (Intensions Revisited [1977], p.121)
     A reaction: Lots of things are assumed by an inquiry without an assumption that they must be true. Quine is the greatest opponent of necessity in all of philosophy. Asserting necessities, though, is too much fun to give up. It would ruin philosophy.
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds are a way to dramatise essentialism, and yet they presuppose essentialism [Quine]
     Full Idea: Talk of possible worlds is a graphic way of waging the essentialist philosophy, but it is only that; it is not an explication. Essence is needed to identify an object from one possible world to another.
     From: Willard Quine (Intensions Revisited [1977], p.118)
     A reaction: He makes the proposal sound circular, but I take a commitment to essences to be prior to talk of possible worlds. Possible worlds are a tool for clarifying modalities, not for clarifying essential identities.
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
Could possible Adam gradually transform into Noah, and vice versa? [Chisholm]
     Full Idea: If Adam lived for 931 years in a possible world, instead of his actual 930 years, ..then Adam and Noah could gradually exchange their ages and other properties...and we could trace Adam in a world back to the actual Noah, and vice versa.
     From: Roderick Chisholm (Identity through Possible Worlds [1967], p.81-2)
     A reaction: [very compressed] Chisholm was one of the first to raise this problem for possible worlds, though it had been Quine's objection to modal logic all along. Only Adam having essential properties seems to stop this slippery slope, says Chisholm.
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
A rigid designator (for all possible worlds) picks out an object by its essential traits [Quine]
     Full Idea: A rigid designator differs from others in that it picks out its object by essential traits. It designates the object in all possible worlds in which it exists.
     From: Willard Quine (Intensions Revisited [1977], p.118)
     A reaction: This states the point more clearly than Kripke ever does, and I presume it is right. Thus when we say that we wish 'our' Hubert Humphrey had won the election, we can allow that his victory elation would change him a bit. Kripke is right.
11. Knowledge Aims / A. Knowledge / 4. Belief / a. Beliefs
Beliefs can be ascribed to machines [Quine]
     Full Idea: Beliefs have been ascribed to machines, in support of a mechanistic philosophy, and I share this attitude.
     From: Willard Quine (Intensions Revisited [1977], p.123)
     A reaction: [He cites Raymond Nelson] One suspects that this is Quine's latent behaviourism speaking. It strikes me as a crass misuse of 'belief' to ascribe it to a simple machine like a thermostat.