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All the ideas for 'Intensional Logic', 'First Things First' and 'Bayesianism'

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13 ideas

4. Formal Logic / E. Nonclassical Logics / 8. Intensional Logic
If terms change their designations in different states, they are functions from states to objects [Fitting]
     Full Idea: The common feature of every designating term is that designation may change from state to state - thus it can be formalized by a function from states to objects.
     From: Melvin Fitting (Intensional Logic [2007], 3)
     A reaction: Specifying the objects sounds OK, but specifying states sounds rather tough.
Intensional logic adds a second type of quantification, over intensional objects, or individual concepts [Fitting]
     Full Idea: To first order modal logic (with quantification over objects) we can add a second kind of quantification, over intensions. An intensional object, or individual concept, will be modelled by a function from states to objects.
     From: Melvin Fitting (Intensional Logic [2007], 3.3)
4. Formal Logic / E. Nonclassical Logics / 9. Awareness Logic
Awareness logic adds the restriction of an awareness function to epistemic logic [Fitting]
     Full Idea: Awareness logic enriched Hintikka's epistemic models with an awareness function, mapping each state to the set of formulas we are aware of at that state. This reflects some bound on the resources we can bring to bear.
     From: Melvin Fitting (Intensional Logic [2007], 3.6.1)
     A reaction: [He cites Fagin and Halpern 1988 for this]
4. Formal Logic / E. Nonclassical Logics / 10. Justification Logics
Justication logics make explicit the reasons for mathematical truth in proofs [Fitting]
     Full Idea: In justification logics, the logics of knowledge are extended by making reasons explicit. A logic of proof terms was created, with a semantics. In this, mathematical truths are known for explicit reasons, and these provide a measure of complexity.
     From: Melvin Fitting (Intensional Logic [2007], 3.6.1)
5. Theory of Logic / A. Overview of Logic / 8. Logic of Mathematics
Classical logic is deliberately extensional, in order to model mathematics [Fitting]
     Full Idea: Mathematics is typically extensional throughout (we write 3+2=2+3 despite the two terms having different meanings). ..Classical first-order logic is extensional by design since it primarily evolved to model the reasoning of mathematics.
     From: Melvin Fitting (Intensional Logic [2007], §1)
5. Theory of Logic / F. Referring in Logic / 3. Property (λ-) Abstraction
λ-abstraction disambiguates the scope of modal operators [Fitting]
     Full Idea: λ-abstraction can be used to abstract and disambiguate a predicate. De re is [λx◊P(x)](f) - f has the possible-P property - and de dicto is ◊[λxP(x)](f) - possibly f has the P-property. Also applies to □.
     From: Melvin Fitting (Intensional Logic [2007], §3.3)
     A reaction: Compare the Barcan formula. Originated with Church in the 1930s, and Carnap 1947, but revived by Stalnaker and Thomason 1968. Because it refers to the predicate, it has a role in intensional versions of logic, especially modal logic.
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
Definite descriptions pick out different objects in different possible worlds [Fitting]
     Full Idea: Definite descriptions pick out different objects in different possible worlds quite naturally.
     From: Melvin Fitting (Intensional Logic [2007], 3.4)
     A reaction: A definite description can pick out the same object in another possible world, or a very similar one, or an object which has almost nothing in common with the others.
13. Knowledge Criteria / B. Internal Justification / 3. Evidentialism / b. Evidentialism
Evidentialism is not axiomatic; the evidence itself inclines us towards evidentialism [Conee]
     Full Idea: Evidentialism does not support beginning epistemology by taking for granted that evidentialism is true. ...Rather, what potentially justifies belief in intial epistemic data and initial procedures of inquiry is the evidence itself.
     From: Earl Conee (First Things First [2004], 'Getting')
     A reaction: This sounds good. I much prefer talk of 'evidence' to talk of 'perceptions', because evidence has been licked into shape, and its significance has been clarified. That is the first step towards the coherence we seek.
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / b. Anti-reliabilism
If pure guesses were reliable, reliabilists would have to endorse them [Conee]
     Full Idea: Reliabilism would count pure guesses as good reasons if guessing were properly reliable.
     From: Earl Conee (First Things First [2004], 'Getting')
     A reaction: See D.H. Lawrence's short story 'The Rocking Horse Winner'. This objection strikes me as being so devastating that it is almost conclusive. Except that pure guesses are never ever reliable, over a decent period of time.
More than actual reliability is needed, since I may mistakenly doubt what is reliable [Conee]
     Full Idea: Sheer reliability does not justify belief. ...It may be, for instance, that we have strong though misleading reason to deny the method's reliability.
     From: Earl Conee (First Things First [2004], 'Circles')
     A reaction: That is, we accept a justification if we judge the method to be reliable, not if it IS reliable. I can disbelieve all the reliable information that arrives in my mind. People do that all the time! Hatred of experts! Support for internalism?
Reliabilism is poor on reflective judgements about hypothetical cases [Conee]
     Full Idea: An unrefined reliability theory does a poor job at capturing reflective judgements about hypothetical cases
     From: Earl Conee (First Things First [2004], 'Stroud's')
     A reaction: Reliability can only be a test for tried and tested ways. No one can say whether imagining a range of possibilities is reliable or not. Is prediction a reliable route to knowledge?
14. Science / C. Induction / 6. Bayes's Theorem
Probability of H, given evidence E, is prob(H) x prob(E given H) / prob(E) [Horwich]
     Full Idea: Bayesianism says ideally rational people should have degrees of belief (not all-or-nothing beliefs), corresponding with probability theory. Probability of H, given evidence E, is prob(H) X prob(E given H) / prob(E).
     From: Paul Horwich (Bayesianism [1992], p.41)
Bayes' theorem explains why very surprising predictions have a higher value as evidence [Horwich]
     Full Idea: Bayesianism can explain the fact that in science surprising predictions have greater evidential value, as the equation produces a higher degree of confirmation.
     From: Paul Horwich (Bayesianism [1992], p.42)