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All the ideas for 'On What Grounds What', 'Must We Believe in Set Theory?' and 'The Rationality of Science'

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39 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Modern Quinean metaphysics is about what exists, but Aristotelian metaphysics asks about grounding [Schaffer,J]
     Full Idea: On the now dominant Quinean view, metaphysics is about what there is (such as properties, meanings and numbers). I will argue for the revival of a more traditional Aristotelian view, on which metaphysics is about what grounds what.
     From: Jonathan Schaffer (On What Grounds What [2009], Intro)
     A reaction: I find that an enormously helpful distinction, and support the Aristotelian view. Schaffer's general line is that what exists is fairly uncontroversial and dull, but the interesting truths about the world emerge when we grasp its structure.
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
If you tore the metaphysics out of philosophy, the whole enterprise would collapse [Schaffer,J]
     Full Idea: Traditional metaphysics is so tightly woven into the fabric of philosophy that it cannot be torn out without the whole tapestry unravelling.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.3)
     A reaction: I often wonder why the opponents of metaphysics still continue to do philosophy. I don't see how you address questions of ethics, or philosophy of mathematics (etc) without coming up against highly general and abstract over-questions.
1. Philosophy / G. Scientific Philosophy / 1. Aims of Science
The real problem of science is how to choose between possible explanations [Newton-Smith]
     Full Idea: Once we move beyond investigating correlations between observables the question of what does or should guide our choice between alternative explanatory accounts becomes problematic.
     From: W.H. Newton-Smith (The Rationality of Science [1981], IX.2)
For science to be rational, we must explain scientific change rationally [Newton-Smith]
     Full Idea: We are only justified in regarding scientific practice as the very paradigm of rationality if we can justify the claim that scientific change is rationally explicable.
     From: W.H. Newton-Smith (The Rationality of Science [1981], I.2)
We do not wish merely to predict, we also want to explain [Newton-Smith]
     Full Idea: We do not wish merely to predict, we also want to explain.
     From: W.H. Newton-Smith (The Rationality of Science [1981], II.3)
1. Philosophy / G. Scientific Philosophy / 2. Positivism
Critics attack positivist division between theory and observation [Newton-Smith]
     Full Idea: The critics of positivism attacked the conception of a dichotomy between theory and observation.
     From: W.H. Newton-Smith (The Rationality of Science [1981], I.4)
Positivists hold that theoretical terms change, but observation terms don't [Newton-Smith]
     Full Idea: For positivists it was taken that while theory change meant change in the meaning of theoretical terms, the meaning of observational terms was invariant under theory change.
     From: W.H. Newton-Smith (The Rationality of Science [1981], I.4)
2. Reason / B. Laws of Thought / 6. Ockham's Razor
We should not multiply basic entities, but we can have as many derivative entities as we like [Schaffer,J]
     Full Idea: Occam's Razor should only be understood to concern substances: do not multiply basic entities without necessity. There is no problem with the multiplication of derivative entities - they are an 'ontological free lunch'.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: The phrase 'ontological free lunch' comes from Armstrong. This is probably what Occam meant. A few extra specks of dust, or even a few more numbers (thank you, Cantor!) don't seem to challenge the principle.
3. Truth / A. Truth Problems / 6. Verisimilitude
Theories generate infinite truths and falsehoods, so they cannot be used to assess probability [Newton-Smith]
     Full Idea: We cannot explicate a useful notion of verisimilitude in terms of the number of truths and the number of falsehoods generated by a theory, because they are infinite.
     From: W.H. Newton-Smith (The Rationality of Science [1981], III.4)
More truthful theories have greater predictive power [Newton-Smith]
     Full Idea: If a theory is a better approximation to the truth, then it is likely that it will have greater predictive power.
     From: W.H. Newton-Smith (The Rationality of Science [1981], VIII.8)
4. Formal Logic / F. Set Theory ST / 1. Set Theory
The logic of ZF is classical first-order predicate logic with identity [Boolos]
     Full Idea: The logic of ZF Set Theory is classical first-order predicate logic with identity.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.121)
     A reaction: This logic seems to be unable to deal with very large cardinals, precisely those that are implied by set theory, so there is some sort of major problem hovering here. Boolos is fairly neutral.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
A few axioms of set theory 'force themselves on us', but most of them don't [Boolos]
     Full Idea: Maybe the axioms of extensionality and the pair set axiom 'force themselves on us' (Gödel's phrase), but I am not convinced about the axioms of infinity, union, power or replacement.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.130)
     A reaction: Boolos is perfectly happy with basic set theory, but rather dubious when very large cardinals come into the picture.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets
Naïve sets are inconsistent: there is no set for things that do not belong to themselves [Boolos]
     Full Idea: The naïve view of set theory (that any zero or more things form a set) is natural, but inconsistent: the things that do not belong to themselves are some things that do not form a set.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.127)
     A reaction: As clear a summary of Russell's Paradox as you could ever hope for.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The iterative conception says sets are formed at stages; some are 'earlier', and must be formed first [Boolos]
     Full Idea: According to the iterative conception, every set is formed at some stage. There is a relation among stages, 'earlier than', which is transitive. A set is formed at a stage if and only if its members are all formed before that stage.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.126)
     A reaction: He gives examples of the early stages, and says the conception is supposed to 'justify' Zermelo set theory. It is also supposed to make the axioms 'natural', rather than just being selected for convenience. And it is consistent.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Infinite natural numbers is as obvious as infinite sentences in English [Boolos]
     Full Idea: The existence of infinitely many natural numbers seems to me no more troubling than that of infinitely many computer programs or sentences of English. There is, for example, no longest sentence, since any number of 'very's can be inserted.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.129)
     A reaction: If you really resisted an infinity of natural numbers, presumably you would also resist an actual infinity of 'very's. The fact that it is unclear what could ever stop a process doesn't guarantee that the process is actually endless.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
Mathematics and science do not require very high orders of infinity [Boolos]
     Full Idea: To the best of my knowledge nothing in mathematics or science requires the existence of very high orders of infinity.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.122)
     A reaction: He is referring to particular high orders of infinity implied by set theory. Personally I want to wield Ockham's Razor. Is being implied by set theory a sufficient reason to accept such outrageous entities into our ontology?
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
Mathematics isn't surprising, given that we experience many objects as abstract [Boolos]
     Full Idea: It is no surprise that we should be able to reason mathematically about many of the things we experience, for they are already 'abstract'.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.129)
     A reaction: He has just given a list of exemplary abstract objects (Idea 10489), but I think there is a more interesting idea here - that our experience of actual physical objects is to some extent abstract, as soon as it is conceptualised.
If 'there are red roses' implies 'there are roses', then 'there are prime numbers' implies 'there are numbers' [Schaffer,J]
     Full Idea: We can automatically infer 'there are roses' from 'there are red roses' (with no shift in the meaning of 'roses'). Likewise one can automatically infer 'there are numbers' from 'there are prime numbers'.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: He similarly observes that the atheist's 'God is a fictional character' implies 'there are fictional characters'. Schaffer is not committing to a strong platonism with his claim - merely that the existence of numbers is hardly worth disputing.
7. Existence / C. Structure of Existence / 1. Grounding / a. Nature of grounding
Grounding is unanalysable and primitive, and is the basic structuring concept in metaphysics [Schaffer,J]
     Full Idea: Grounding should be taken as primitive, as per the neo-Aristotelian approach. Grounding is an unanalyzable but needed notion - it is the primitive structuring conception of metaphysics.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.2)
     A reaction: [he cites K.Fine 1991] I find that this simple claim clarifies the discussions of Kit Fine, where you are not always quite sure what the game is. I agree fully with it. It makes metaphysics interesting, where cataloguing entities is boring.
7. Existence / C. Structure of Existence / 5. Supervenience / a. Nature of supervenience
Supervenience is just modal correlation [Schaffer,J]
     Full Idea: Supervenience is mere modal correlation.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.2)
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
The cosmos is the only fundamental entity, from which all else exists by abstraction [Schaffer,J]
     Full Idea: My preferred view is that there is only one fundamental entity - the whole concrete cosmos - from which all else exists by abstraction.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: This looks to me like weak anti-realism - that there are no natural 'joints' in nature - but I don't think Schaffer intends that. I take the joints to be fundamentals, which necessitates that the cosmos has parts. His 'abstraction' is clearly a process.
7. Existence / E. Categories / 4. Category Realism
Maybe categories are just the different ways that things depend on basic substances [Schaffer,J]
     Full Idea: Maybe the categories are determined by the different grounding relations, ..so that categories just are the ways things depend on substances. ...Categories are places in the dependence ordering.
     From: Jonathan Schaffer (On What Grounds What [2009], 1.3)
8. Modes of Existence / D. Universals / 1. Universals
It is lunacy to think we only see ink-marks, and not word-types [Boolos]
     Full Idea: It's a kind of lunacy to think that sound scientific philosophy demands that we think that we see ink-tracks but not words, i.e. word-types.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.128)
     A reaction: This seems to link him with Armstrong's mockery of 'ostrich nominalism'. There seems to be some ambiguity with the word 'see' in this disagreement. When we look at very ancient scratches on stones, why don't we always 'see' if it is words?
9. Objects / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
I am a fan of abstract objects, and confident of their existence [Boolos]
     Full Idea: I am rather a fan of abstract objects, and confident of their existence. Smaller numbers, sets and functions don't offend my sense of reality.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.128)
     A reaction: The great Boolos is rather hard to disagree with, but I disagree. Logicians love abstract objects, indeed they would almost be out of a job without them. It seems to me they smuggle them into our ontology by redefining either 'object' or 'exists'.
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
We deal with abstract objects all the time: software, poems, mistakes, triangles.. [Boolos]
     Full Idea: We twentieth century city dwellers deal with abstract objects all the time, such as bank balances, radio programs, software, newspaper articles, poems, mistakes, triangles.
     From: George Boolos (Must We Believe in Set Theory? [1997], p.129)
     A reaction: I find this claim to be totally question-begging, and typical of a logician. The word 'object' gets horribly stretched in these discussions. We can create concepts which have all the logical properties of objects. Maybe they just 'subsist'?
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
There exist heaps with no integral unity, so we should accept arbitrary composites in the same way [Schaffer,J]
     Full Idea: I am happy to accept universal composition, on the grounds that there are heaps, piles etc with no integral unity, and that arbitrary composites are no less unified than heaps.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1 n11)
     A reaction: The metaphysical focus is then placed on what constitutes 'integral unity', which is precisely the question which most interested Aristotle. Clearly if there is nothing more to an entity than its components, scattering them isn't destruction.
The notion of 'grounding' can explain integrated wholes in a way that mere aggregates can't [Schaffer,J]
     Full Idea: The notion of grounding my capture a crucial mereological distinction (missing from classical mereology) between an integrated whole with genuine unity, and a mere aggregate. x is an integrated whole if it grounds its proper parts.
     From: Jonathan Schaffer (On What Grounds What [2009], 3.1)
     A reaction: That gives a nice theoretical notion, but if you remove each of the proper parts, does x remain? Is it a bare particular? I take it that it will have to be an abstract principle, the one Aristotle was aiming at with his notion of 'form'. Schaffer agrees.
10. Modality / C. Sources of Modality / 1. Sources of Necessity
De re necessity arises from the way the world is [Newton-Smith]
     Full Idea: A necessary truth is 'de re' if its necessity arises from the way the world is.
     From: W.H. Newton-Smith (The Rationality of Science [1981], VII.6)
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
Belief in impossible worlds may require dialetheism [Schaffer,J]
     Full Idea: One motivation for dialetheism is the view that there are impossible worlds.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.3)
11. Knowledge Aims / A. Knowledge / 4. Belief / a. Beliefs
We must assess the truth of beliefs in identifying them [Newton-Smith]
     Full Idea: We cannot determine what someone's beliefs are independently of assessing to some extent the truth or falsity of the beliefs.
     From: W.H. Newton-Smith (The Rationality of Science [1981], X.4)
11. Knowledge Aims / B. Certain Knowledge / 2. Common Sense Certainty
'Moorean certainties' are more credible than any sceptical argument [Schaffer,J]
     Full Idea: A 'Moorean certainty' is when something is more credible than any philosopher's argument to the contrary.
     From: Jonathan Schaffer (On What Grounds What [2009], 2.1)
     A reaction: The reference is to G.E. Moore's famous claim that the existence of his hand is more certain than standard sceptical arguments. It sounds empiricist, but they might be parallel rational truths, of basic logic or arithmetic.
13. Knowledge Criteria / E. Relativism / 6. Relativism Critique
Defeat relativism by emphasising truth and reference, not meaning [Newton-Smith]
     Full Idea: The challenge of incommensurability can be met once it is realised that in comparing theories the notions of truth and reference are more important than that of meaning.
     From: W.H. Newton-Smith (The Rationality of Science [1981], I.6)
14. Science / A. Basis of Science / 1. Observation
A full understanding of 'yellow' involves some theory [Newton-Smith]
     Full Idea: A full grasp of the concept '…is yellow' involves coming to accept as true bits of theory; that is, generalisations involving the term 'yellow'.
     From: W.H. Newton-Smith (The Rationality of Science [1981], II.2)
14. Science / A. Basis of Science / 5. Anomalies
Anomalies are judged against rival theories, and support for the current theory [Newton-Smith]
     Full Idea: Whether to reject an anomaly has to be decided on the basis of the availability of a rival theory, and on the basis of the positive evidence for the theory in question.
     From: W.H. Newton-Smith (The Rationality of Science [1981], III.9)
The anomaly of Uranus didn't destroy Newton's mechanics - it led to Neptune's discovery [Newton-Smith]
     Full Idea: When scientists observed the motion of Uranus, they did not give up on Newtonian mechanics. Instead they posited the existence of Neptune.
     From: W.H. Newton-Smith (The Rationality of Science [1981], III.9)
All theories contain anomalies, and so are falsified! [Newton-Smith]
     Full Idea: According to Feyerabend all theories are born falsified, because no theory has ever been totally free of anomalies.
     From: W.H. Newton-Smith (The Rationality of Science [1981], III.9)
14. Science / B. Scientific Theories / 1. Scientific Theory
Why should it matter whether or not a theory is scientific? [Newton-Smith]
     Full Idea: Why should it be so important to distinguish between theories that are scientific and those that are not?
     From: W.H. Newton-Smith (The Rationality of Science [1981], IV.3)
14. Science / B. Scientific Theories / 5. Commensurability
If theories are really incommensurable, we could believe them all [Newton-Smith]
     Full Idea: If theories are genuinely incommensurable why should I be faced with the problem of choosing between them? Why not believe them all?
     From: W.H. Newton-Smith (The Rationality of Science [1981], VII.1)
20. Action / C. Motives for Action / 3. Acting on Reason / c. Reasons as causes
Explaining an action is showing that it is rational [Newton-Smith]
     Full Idea: To explain an action as an action is to show that it is rational.
     From: W.H. Newton-Smith (The Rationality of Science [1981], X.2)