Combining Texts

All the ideas for 'Of Liberty and Necessity', 'On 'Insolubilia' and their solution' and 'Aquinas, Thomas'

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5 ideas

4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / c. Logical sets
The 'no classes' theory says the propositions just refer to the members [Russell]
     Full Idea: The contention of the 'no classes' theory is that all significant propositions concerning classes can be regarded as propositions about all or some of their members.
     From: Bertrand Russell (On 'Insolubilia' and their solution [1906], p.200)
     A reaction: Apparently this theory has not found favour with later generations of theorists. I see it in terms of Russell trying to get ontology down to the minimum, in the spirit of Goodman and Quine.
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / d. Richard's paradox
Richard's puzzle uses the notion of 'definition' - but that cannot be defined [Russell]
     Full Idea: In Richard's puzzle, we use the notion of 'definition', and this, oddly enough, is not definable, and is indeed not a definite notion at all.
     From: Bertrand Russell (On 'Insolubilia' and their solution [1906], p.209)
     A reaction: The background for this claim is his type theory, which renders certain forms of circular reference meaningless.
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
Vicious Circle: what involves ALL must not be one of those ALL [Russell]
     Full Idea: The 'vicious-circle principle' says 'whatever involves an apparent variable must not be among the possible values of that variable', or (less exactly) 'whatever involves ALL must not be one of ALL which it involves.
     From: Bertrand Russell (On 'Insolubilia' and their solution [1906], p.204)
     A reaction: He offers this as a parallel to his 'no classes' principle. That referred to classes, but this refers to propositions, and specifically the Liar Paradox (which he calls the 'Epimenedes').
10. Modality / B. Possibility / 5. Contingency
'Contingent' means that the cause is unperceived, not that there is no cause [Hobbes]
     Full Idea: For contingent, men do not mean that which hath no cause, but that which hath not for cause any thing that we perceive, as when a traveller meets a shower, they both had sufficient causes, but they didn't cause one another, so we say it was contingent.
     From: Thomas Hobbes (Of Liberty and Necessity [1654], §95)
     A reaction: Contingent nowadays means 'might not have happened', or 'does not happen in all possible worlds'. Personally I share Hobbes' doubts about the concept of contingency, and this is quite a good account of the misunderstanding.
14. Science / A. Basis of Science / 2. Demonstration
Demonstration provides depth of understanding and explanation (rather than foundations) [Kretzmann/Stump]
     Full Idea: According to Aquinas, what demonstration provides is not so much knowledge as conceived by foundationalists as depth of understanding and explanatory insight.
     From: Kretzmann/Stump (Aquinas, Thomas [2005]), quoted by Kretzmann/Stump - Aquinas, Thomas 11
     A reaction: It was noticeable that Aristotle didn't make clear what demonstration aims to achieve, and he didn't employ it elsewhere in his writings. We aim for understanding, not for well grounded propositions. Understanding needs implications and mechanisms.