Combining Texts

All the ideas for 'The Case for Closure', 'New Foundations for Mathematical Logic' and 'Daniel Dennett on himself'

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10 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
NF has no models, but just blocks the comprehension axiom, to avoid contradictions [Quine, by Dummett]
     Full Idea: Quine's New Foundations system of set theory, devised with no model in mind, but on the basis of a hunch that a purely formal restriction on the comprehension axiom would block all contradictions.
     From: report of Willard Quine (New Foundations for Mathematical Logic [1937]) by Michael Dummett - Frege philosophy of mathematics Ch.18
     A reaction: The point is that Quine (who had an ontological preference for 'desert landscapes') attempted to do without an ontological commitment to objects (and their subsequent models), with a purely formal system. Quine's NF is not now highly regarded.
11. Knowledge Aims / B. Certain Knowledge / 2. Common Sense Certainty
Commitment to 'I have a hand' only makes sense in a context where it has been doubted [Hawthorne]
     Full Idea: If I utter 'I know I have a hand' then I can only be reckoned a cooperative conversant by my interlocutors on the assumption that there was a real question as to whether I have a hand.
     From: John Hawthorne (The Case for Closure [2005], 2)
     A reaction: This seems to point to the contextualist approach to global scepticism, which concerns whether we are setting the bar high or low for 'knowledge'.
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / c. Knowledge closure
How can we know the heavyweight implications of normal knowledge? Must we distort 'knowledge'? [Hawthorne]
     Full Idea: Those who deny skepticism but accept closure will have to explain how we know the various 'heavyweight' skeptical hypotheses to be false. Do we then twist the concept of knowledge to fit the twin desiderata of closue and anti-skepticism?
     From: John Hawthorne (The Case for Closure [2005], Intro)
     A reaction: [He is giving Dretske's view; Dretske says we do twist knowledge] Thus if I remember yesterday, that has the heavyweight implication that the past is real. Hawthorne nicely summarises why closure produces a philosophical problem.
We wouldn't know the logical implications of our knowledge if small risks added up to big risks [Hawthorne]
     Full Idea: Maybe one cannot know the logical consequences of the proposition that one knows, on account of the fact that small risks add up to big risks.
     From: John Hawthorne (The Case for Closure [2005], 1)
     A reaction: The idea of closure is that the new knowledge has the certainty of logic, and each step is accepted. An array of receding propositions can lose reliability, but that shouldn't apply to logic implications. Assuming monotonic logic, of course.
Denying closure is denying we know P when we know P and Q, which is absurd in simple cases [Hawthorne]
     Full Idea: How could we know that P and Q but not be in a position to know that P (as deniers of closure must say)? If my glass is full of wine, we know 'g is full of wine, and not full of non-wine'. How can we deny that we know it is not full of non-wine?
     From: John Hawthorne (The Case for Closure [2005], 2)
     A reaction: Hawthorne merely raises this doubt. Dretske is concerned with heavyweight implications, but how do you accept lightweight implications like this one, and then suddenly reject them when they become too heavy? [see p.49]
17. Mind and Body / B. Behaviourism / 3. Intentional Stance
The 'intentional stance' is a way of interpreting an entity by assuming it is rational and self-aware [Dennett]
     Full Idea: The 'intentional stance' is the tactic of interpreting an entity by adopting the presupposition that it is an approximation of the ideal of an optimally designed (i.e. rational) self-regarding agent.
     From: Daniel C. Dennett (Daniel Dennett on himself [1994], p.239)
     A reaction: This is Dennett's 'instrumentalism', a descendant of behaviourism, which strikes me as a pragmatist's evasion of the ontological problems of mind which should interest philosophers
18. Thought / A. Modes of Thought / 4. Folk Psychology
Like the 'centre of gravity', desires and beliefs are abstract concepts with no actual existence [Dennett]
     Full Idea: Like such abstracta as centres of gravity and parallelograms of force, the beliefs and desires posited by the highest intentional stance have no independent and concrete existence.
     From: Daniel C. Dennett (Daniel Dennett on himself [1994], p.239)
     A reaction: I don't see why we shouldn't one day have a physical account of the distinctive brain events involved in a belief or a desire
18. Thought / C. Content / 9. Conceptual Role Semantics
The nature of content is entirely based on its functional role [Dennett]
     Full Idea: All attributions of content are founded on an appreciation of the functional roles of the items in question.
     From: Daniel C. Dennett (Daniel Dennett on himself [1994], p.239)
     A reaction: This seems wrong to me. How can anything's nature be its function? It must have intrinsic characteristics in order to have the function. This is an evasion.
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learning is evolution in the brain [Dennett]
     Full Idea: Learning is evolution in the brain.
     From: Daniel C. Dennett (Daniel Dennett on himself [1994], p.238)
     A reaction: This is a rather non-conscious, associationist view, connected to Dawkins' idea of 'memes'. It seems at least partially correct.
27. Natural Reality / G. Biology / 1. Biology
Biology is a type of engineering, not a search for laws of nature [Dennett]
     Full Idea: Biology is not a science like physics, in which one should strive to find 'laws of nature', but a species of engineering.
     From: Daniel C. Dennett (Daniel Dennett on himself [1994], p.239)
     A reaction: Yes. This is also true of chemistry, which has always struck me as minitiarised car mechanics.