Combining Texts

All the ideas for 'The Sign of Four', 'Absolute Necessities' and 'The Nature of Rationality'

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15 ideas

3. Truth / A. Truth Problems / 3. Value of Truth
I do not care if my trivial beliefs are false, and I have no interest in many truths [Nozick]
     Full Idea: I find that I do not mind at all the thought that I have some false beliefs (of US state capitals), and there are many truths I do not care to know at all (total grains of sand on the beach).
     From: Robert Nozick (The Nature of Rationality [1993], p.67)
     A reaction: A useful corrective to anyone who blindly asserts that truth is the supreme human value. I would still be annoyed if someone taught me lies about these two types of truth.
3. Truth / E. Pragmatic Truth / 1. Pragmatic Truth
Maybe James was depicting the value of truth, and not its nature [Nozick]
     Full Idea: We might see William James's pragmatic view that truth is what works as depicting the value of truth, and not its nature.
     From: Robert Nozick (The Nature of Rationality [1993], p.68)
     A reaction: James didn't think that he was doing this. He firmly says that this IS truth, not just the advantages of truth. Another view is that pragmatists are giving a test for truth.
10. Modality / A. Necessity / 2. Nature of Necessity
Absolute necessity might be achievable either logically or metaphysically [Hale]
     Full Idea: Maybe peaceful co-existence between absolute logical necessity and absolute metaphysical necessity can be secured, ..and absolute necessity is their union. ...However, a truth would then qualify as absolutely necessary in two quite different ways.
     From: Bob Hale (Absolute Necessities [1996], 4)
     A reaction: Hale is addressing a really big question for metaphysic (absolute necessity) which others avoid. In the end he votes for rejecting 'metaphysical' necessity. I am tempted to vote for rejecting logical necessity (as being relative). 'Absolute' is an ideal.
10. Modality / A. Necessity / 3. Types of Necessity
Maybe not-p is logically possible, but p is metaphysically necessary, so the latter is not absolute [Hale]
     Full Idea: It might be metaphysically necessary that p but logically possible that not-p, so that metaphysical necessity is not, after all, absolute.
     From: Bob Hale (Absolute Necessities [1996]), quoted by E.J. Lowe - The Possibility of Metaphysics 1.5
     A reaction: Lowe presents this as dilemma, but it sounds fine to me. Flying pigs etc. have no apparent logical problems, but I can't conceive of a possible world where pigs like ours fly in a world like ours. Earthbound pigs may be metaphysically necessary.
A strong necessity entails a weaker one, but not conversely; possibilities go the other way [Hale]
     Full Idea: One type of necessity may be said to be 'stronger' than another when the first always entails the second, but not conversely. This will obtain only if the possibility of the first is weaker than the possibility of the second.
     From: Bob Hale (Absolute Necessities [1996], 1)
     A reaction: Thus we would normally say that if something is logically necessary (a very strong claim) then it will have to be naturally necessary. If something is naturally possible, then clearly it will have to be logically possible. Sounds OK.
'Relative' necessity is just a logical consequence of some statements ('strong' if they are all true) [Hale]
     Full Idea: Necessity is 'relative' if a claim of φ-necessary that p just claims that it is a logical consequence of some statements Φ that p. We have a 'strong' version if we add that the statements in Φ are all true, and a 'weak' version if not.
     From: Bob Hale (Absolute Necessities [1996], 1)
     A reaction: I'm not sure about 'logical' consequence here. It may be necessary that a thing be a certain way in order to qualify for some category (which would be 'relative'), but that seems like 'sortal' necessity rather than logical.
10. Modality / A. Necessity / 5. Metaphysical Necessity
Metaphysical necessity says there is no possibility of falsehood [Hale]
     Full Idea: Friends of metaphysical necessity would want to hold that when it is metaphysically necessary that p, there is no good sense of 'possible' (except, perhaps, an epistemic one) in which it is possible that not-p.
     From: Bob Hale (Absolute Necessities [1996], 2)
     A reaction: We might want to say which possible worlds this refers to (and presumably it won't just be in the actual world). The normal claim would refer to all possible worlds. Adding a '...provided that' clause moves it from absolute to relative necessity.
10. Modality / A. Necessity / 6. Logical Necessity
'Broadly' logical necessities are derived (in a structure) entirely from the concepts [Hale]
     Full Idea: 'Broadly' logical necessities are propositions whose truth derives entirely from the concepts involved in them (together, of course, with relevant structure).
     From: Bob Hale (Absolute Necessities [1996], 3)
     A reaction: Is the 'logical' part of this necessity bestowed by the concepts, or by the 'structure' (which I take to be a logical structure)?
Logical necessities are true in virtue of the nature of all logical concepts [Hale]
     Full Idea: The logical necessities can be taken to be the propositions which are true in virtue of the nature of all logical concepts.
     From: Bob Hale (Absolute Necessities [1996], p.10)
     A reaction: This is part of his story of essences giving rise to necessities. His proposal sounds narrow, but logical concepts may have the highest degree of generality which it is possible to have. It must be how the concepts connect that causes the necessities.
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
Conceptual necessities are made true by all concepts [Hale]
     Full Idea: Conceptual necessities can be taken to be propositions which are true in virtue of the nature of all concepts.
     From: Bob Hale (Absolute Necessities [1996], p.9)
     A reaction: Fine endorse essences for these concepts. Could we then come up with a new concept which contradicted all the others, and destroyed the necessity? Yes, presumably. Presumably witchcraft and astrology are full of 'conceptual necessities'.
14. Science / C. Induction / 1. Induction
If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle]
     Full Idea: When you have eliminated the impossible, whatever remains, however improbable, must be the truth.
     From: Arthur Conan Doyle (The Sign of Four [1890], Ch. 6)
     A reaction: A beautiful statement, by Sherlock Holmes, of Eliminative Induction. It is obviously not true, of course. Many options may still face you after you have eliminated what is actually impossible.
18. Thought / A. Modes of Thought / 5. Rationality / a. Rationality
In the instrumental view of rationality it only concerns means, and not ends [Nozick]
     Full Idea: On the instrumental conception of rationality, it consists in the effective and efficient achievement of goals, ends, and desires. About the goals themselves it has little to say.
     From: Robert Nozick (The Nature of Rationality [1993], p.64)
     A reaction: [He quotes Russell 1954 p.viii as expressing this view] A long way from Greek logos, which obviously concerns the rational selection of right ends (for which, presumably, reasons can be given). In practice our ends may never be rational, of course.
Is it rational to believe a truth which leads to permanent misery? [Nozick]
     Full Idea: If a mother is presented with convincing evidence that her son has committed a grave crime, but were she to believe it that would make her life thereafter miserable, is it rational for her to believe her son is guilty?
     From: Robert Nozick (The Nature of Rationality [1993], p.69)
     A reaction: I assume there is a conflict of rationalities, because there are conflicting ends. Presumably most mothers love the truth, but most of us also aim for happy lives. It is perfectly rational to avoid discovering a horrible family truth.
Rationality needs some self-consciousness, to also evaluate how we acquired our reasons [Nozick]
     Full Idea: Rationality involves some degree of self-consciousness. Not only reasons are evaluated, but also the processes by which information arrives, is stored, and recalled.
     From: Robert Nozick (The Nature of Rationality [1993], p.74)
     A reaction: I defend the idea that animals have a degree of rationality, because they can make sensible judgements, but I cannot deny this idea. Rationality comes in degrees, and second-level thought is a huge leap forward in degree.
Rationality is normally said to concern either giving reasons, or reliability [Nozick]
     Full Idea: The two themes permeating the philosophical literature are that rationality is a matter of reasons, or that rationality is a matter of reliability.
     From: Robert Nozick (The Nature of Rationality [1993], p.64)
     A reaction: Since a clock can be reliable, I would have thought it concerns reasons. Or an unthinking person could reliably recite truths from memory. There is also the instrumental view of rationality.