Combining Texts

All the ideas for 'fragments/reports', 'Truth' and 'The Nature of Rationality'

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12 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.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
Truth rests on Elimination ('A' is true → A) and Introduction (A → 'A' is true) [Gupta]
     Full Idea: The basic principles governing truth are Truth Elimination (sentence A follows from ''A' is true') and the converse Truth Introduction (''A' is true' follows from A), which combine into Tarski's T-schema - 'A' is true if and only if A.
     From: Anil Gupta (Truth [2001], 5.1)
     A reaction: Introduction and Elimination rules are the basic components of natural deduction systems, so 'true' now works in the same way as 'and', 'or' etc. This is the logician's route into truth.
3. Truth / F. Semantic Truth / 2. Semantic Truth
A weakened classical language can contain its own truth predicate [Gupta]
     Full Idea: If a classical language is expressively weakened - for example, by dispensing with negation - then it can contain its own truth predicate.
     From: Anil Gupta (Truth [2001], 5.2)
     A reaction: Thus the Tarskian requirement to move to a metalanguage for truth is only a requirement of a reasonably strong language. Gupta uses this to criticise theories that dispense with the metalanguage.
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
The Liar reappears, even if one insists on propositions instead of sentences [Gupta]
     Full Idea: There is the idea that the Liar paradox is solved simply by noting that truth is a property of propositions (not of sentences), and the Liar sentence does not express a proposition. But we then say 'I am not now expressing a true proposition'!
     From: Anil Gupta (Truth [2001], 5.1)
     A reaction: Disappointed to learn this, since I think focusing on propositions (which are unambiguous) rather than sentences solves a huge number of philosophical problems.
Strengthened Liar: either this sentence is neither-true-nor-false, or it is not true [Gupta]
     Full Idea: An example of the Strengthened Liar is the following statement SL: 'Either SL is neither-true-nor-false or it is not true'. This raises a serious problem for any theory that assesses the paradoxes to be neither true nor false.
     From: Anil Gupta (Truth [2001], 5.4.2)
     A reaction: If the sentence is either true or false it reduces to the ordinary Liar. If it is neither true nor false, then it is true.
18. Thought / A. Modes of Thought / 5. Rationality / a. Rationality
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.
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.
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
     Full Idea: Archelaus was the first person to say that the universe is boundless.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]
     Full Idea: Archelaus wrote that life on Earth began in a primeval slime.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus
     A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea.