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All the ideas for 'Concerning the Trinity', 'Principia Mathematica' and 'Varieties of Things'

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59 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / d. Philosophy as puzzles
Philosophy tries to explain how the actual is possible, given that it seems impossible [Macdonald,C]
     Full Idea: Philosophical problems are problems about how what is actual is possible, given that what is actual appears, because of some faulty argument, to be impossible.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: [She is discussing universals when she makes this comment] A very appealing remark, given that most people come into philosophy because of a mixture of wonder and puzzlement. It is a rather Wittgensteinian view, though, that we must cure our own ills.
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
'Did it for the sake of x' doesn't involve a sake, so how can ontological commitments be inferred? [Macdonald,C]
     Full Idea: In 'She did it for the sake of her country' no one thinks that the expression 'the sake' refers to an individual thing, a sake. But given that, how can we work out what the ontological commitments of a theory actually are?
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.1)
     A reaction: For these sorts of reasons it rapidly became obvious that ordinary language analysis wasn't going to reveal much, but it is also a problem for a project like Quine's, which infers an ontology from the terms of a scientific theory.
2. Reason / F. Fallacies / 5. Fallacy of Composition
Don't assume that a thing has all the properties of its parts [Macdonald,C]
     Full Idea: The fallacy of composition makes the erroneous assumption that every property of the things that constitute a thing is a property of the thing as well. But every large object is constituted by small parts, and every red object by colourless parts.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.5)
     A reaction: There are nice questions here like 'If you add lots of smallness together, why don't you get extreme smallness?' Colours always make bad examples in such cases (see Idea 5456). Distinctions are needed here (e.g. Idea 7007).
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
The best known axiomatization of PL is Whitehead/Russell, with four axioms and two rules [Russell/Whitehead, by Hughes/Cresswell]
     Full Idea: The best known axiomatization of PL is Whitehead/Russell. There are four axioms: (p∨p)→p, q→(p∨q), (p→q)→(q∨p), and (q→r)→((p∨q)→(p∨r)), plus Substitution and Modus Ponens rules.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by GE Hughes/M Cresswell - An Introduction to Modal Logic Ch.1
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / p. Axiom of Reducibility
Russell saw Reducibility as legitimate for reducing classes to logic [Linsky,B on Russell/Whitehead]
     Full Idea: The axiom of Reducibility ...is crucial in the reduction of classes to logic, ...and seems to be a quite legitimate logical notion for Russell.
     From: comment on B Russell/AN Whitehead (Principia Mathematica [1913]) by Bernard Linsky - Russell's Metaphysical Logic 6.4
     A reaction: This is an unusual defence of the axiom, which is usually presumed to have been kicked into the long grass by Quine. If one could reduce classes to logic, that would destroy the opposition to logicism in a single neat coup.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Russell denies extensional sets, because the null can't be a collection, and the singleton is just its element [Russell/Whitehead, by Shapiro]
     Full Idea: Russell adduces two reasons against the extensional view of classes, namely the existence of the null class (which cannot very well be a collection), and the unit classes (which would have to be identical with their single elements).
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Stewart Shapiro - Structure and Ontology p.459
     A reaction: Gödel believes in the reality of classes. I have great sympathy with Russell, when people start to claim that sets are not just conveniences to help us think about things, but actual abstract entities. Is the singleton of my pencil is on this table?
We regard classes as mere symbolic or linguistic conveniences [Russell/Whitehead]
     Full Idea: Classes, so far as we introduce them, are merely symbolic or linguistic conveniences, not genuine objects.
     From: B Russell/AN Whitehead (Principia Mathematica [1913], p.72), quoted by Penelope Maddy - Naturalism in Mathematics III.2
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Lewis's 'strict implication' preserved Russell's confusion of 'if...then' with implication [Quine on Russell/Whitehead]
     Full Idea: Russell call 'if...then' implication, when the material conditional is a much better account; C.I.Lewis (in founding modern modal logic) preserved Russell's confusion by creating 'strict implication', and called that implication.
     From: comment on B Russell/AN Whitehead (Principia Mathematica [1913]) by Willard Quine - Reply to Professor Marcus p.177
     A reaction: [A compession of Quine's paragraph]. All of this assumes that logicians can give an accurate account of what if...then means, when ordinary usage is broad and vague. Strict implication seems to drain all the normal meaning out of 'if...then'.
Russell's implication means that random sentences imply one another [Lewis,CI on Russell/Whitehead]
     Full Idea: In Mr Russell's idea of implication, if twenty random sentences from a newspaper were put in a hat, and two of them drawn at random, one will certainly imply the other, and it is an even bet the implication will be mutual.
     From: comment on B Russell/AN Whitehead (Principia Mathematica [1913]) by C.I. Lewis - A Pragmatic Conception of the A Priori p.366
     A reaction: This sort of lament leads modern logicians to suggest 'relevance' as an important criterion. It certainly seems odd that so-called 'classical logic' should contain a principle so at variance with everyday reasoning.
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
Russell unusually saw logic as 'interpreted' (though very general, and neutral) [Russell/Whitehead, by Linsky,B]
     Full Idea: Russell did not view logic as an uninterpreted calculus awaiting interpretations [the modern view]. Rather, logic is a single 'interpreted' body of a priori truths, of propositions rather than sentence forms - but maximally general and topic neutral.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Bernard Linsky - Russell's Metaphysical Logic 1
     A reaction: This is the view which Wittgenstein challenged, saying logic is just conventional. Linsky claims that Russell's logicism is much more plausible, once you understand his view of logic.
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
In 'Principia' a new abstract theory of relations appeared, and was applied [Russell/Whitehead, by Gödel]
     Full Idea: In 'Principia' a young science was enriched with a new abstract theory of relations, ..and not only Cantor's set theory but also ordinary arithmetic and the theory of measurement are treated from this abstract relational standpoint.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Kurt Gödel - Russell's Mathematical Logic p.448
     A reaction: I presume this is accounting for relations in terms of ordered sets.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / i. Reals from cuts
A real number is the class of rationals less than the number [Russell/Whitehead, by Shapiro]
     Full Idea: For Russell the real number 2 is the class of rationals less than 2 (i.e. 2/1). ...Notice that on this definition, real numbers are classes of rational numbers.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Stewart Shapiro - Thinking About Mathematics 5.2
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / a. Defining numbers
Russell takes numbers to be classes, but then reduces the classes to numerical quantifiers [Russell/Whitehead, by Bostock]
     Full Idea: Although Russell takes numbers to be certain classes, his 'no-class' theory then eliminates all mention of classes in favour of the 'propositional functions' that define them; and in the case of the numbers these just are the numerical quantifiers.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by David Bostock - Philosophy of Mathematics 9.B.4
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
'Principia' lacks a precise statement of the syntax [Gödel on Russell/Whitehead]
     Full Idea: What is missing, above all, in 'Principia', is a precise statement of the syntax of the formalism.
     From: comment on B Russell/AN Whitehead (Principia Mathematica [1913]) by Kurt Gödel - Russell's Mathematical Logic p.448
Russell and Whitehead took arithmetic to be higher-order logic [Russell/Whitehead, by Hodes]
     Full Idea: Russell and Whitehead took arithmetic to be higher-order logic, ..and came close to identifying numbers with numerical quantifiers.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Harold Hodes - Logicism and Ontological Commits. of Arithmetic p.148
     A reaction: The point here is 'higher-order'.
Russell and Whitehead were not realists, but embraced nearly all of maths in logic [Russell/Whitehead, by Friend]
     Full Idea: Unlike Frege, Russell and Whitehead were not realists about mathematical objects, and whereas Frege thought that only arithmetic and analysis are branches of logic, they think the vast majority of mathematics (including geometry) is essentially logical.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Michčle Friend - Introducing the Philosophy of Mathematics 3.1
     A reaction: If, in essence, Descartes reduced geometry to algebra (by inventing co-ordinates), then geometry ought to be included. It is characteristic of Russell's hubris to want to embrace everything.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
The ramified theory of types used propositional functions, and covered bound variables [Russell/Whitehead, by George/Velleman]
     Full Idea: Russell and Whitehead's ramified theory of types worked not with sets, but with propositional functions (similar to Frege's concepts), with a more restrictive assignment of variables, insisting that bound, as well as free, variables be of lower type.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.3
     A reaction: I don't fully understand this (and no one seems much interested any more), but I think variables are a key notion, and there is something interesting going on here. I am intrigued by ordinary language which behaves like variables.
The Russell/Whitehead type theory was limited, and was not really logic [Friend on Russell/Whitehead]
     Full Idea: The Russell/Whitehead type theory reduces mathematics to a consistent founding discipline, but is criticised for not really being logic. They could not prove the existence of infinite sets, and introduced a non-logical 'axiom of reducibility'.
     From: comment on B Russell/AN Whitehead (Principia Mathematica [1913]) by Michčle Friend - Introducing the Philosophy of Mathematics 3.6
     A reaction: To have reduced most of mathematics to a founding discipline sounds like quite an achievement, and its failure to be based in pure logic doesn't sound too bad. However, it seems to reduce some maths to just other maths.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
In 'Principia Mathematica', logic is exceeded in the axioms of infinity and reducibility, and in the domains [Bernays on Russell/Whitehead]
     Full Idea: In the system of 'Principia Mathematica', it is not only the axioms of infinity and reducibility which go beyond pure logic, but also the initial conception of a universal domain of individuals and of a domain of predicates.
     From: comment on B Russell/AN Whitehead (Principia Mathematica [1913], p.267) by Paul Bernays - On Platonism in Mathematics p.267
     A reaction: This sort of criticism seems to be the real collapse of the logicist programme, rather than Russell's paradox, or Gödel's Incompleteness Theorems. It just became impossible to stick strictly to logic in the reduction of arithmetic.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
Russell and Whitehead consider the paradoxes to indicate that we create mathematical reality [Russell/Whitehead, by Friend]
     Full Idea: Russell and Whitehead are particularly careful to avoid paradox, and consider the paradoxes to indicate that we create mathematical reality.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Michčle Friend - Introducing the Philosophy of Mathematics 3.1
     A reaction: This strikes me as quite a good argument. It is certainly counterintuitive that reality, and abstractions from reality, would contain contradictions. The realist view would be that we have paradoxes because we have misdescribed the facts.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
To avoid vicious circularity Russell produced ramified type theory, but Ramsey simplified it [Russell/Whitehead, by Shapiro]
     Full Idea: Russell insisted on the vicious circle principle, and thus rejected impredicative definitions, which resulted in an unwieldy ramified type theory, with the ad hoc axiom of reducibility. Ramsey's simpler theory was impredicative and avoided the axiom.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Stewart Shapiro - Thinking About Mathematics 5.2
     A reaction: Nowadays the theory of types seems to have been given up, possibly because it has no real attraction if it lacks the strict character which Russell aspired to.
7. Existence / C. Structure of Existence / 2. Reduction
Reduce by bridge laws (plus property identities?), by elimination, or by reducing talk [Macdonald,C]
     Full Idea: There are four kinds of reduction: the identifying of entities of two theories by means of bridge or correlation laws; the elimination of entities in favour of the other theory; reducing by bridge laws and property identities; and merely reducing talk.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3 n5)
     A reaction: [She gives references] The idea of 'bridge laws' I regard with caution. If bridge laws are ceteris paribus, they are not much help, and if they are strict, or necessary, then there must be an underlying reason for that, which is probably elimination.
7. Existence / E. Categories / 1. Categories
There are two sorts of category - referring to things, and to circumstances of things [Boethius]
     Full Idea: Is it not now clear what the difference is between items in the categories? Some serve to refer to a thing, whereas others serve to refer to the circumstances of a thing.
     From: Boethius (Concerning the Trinity [c.518], Ch. 4), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 12.5
8. Modes of Existence / A. Relations / 2. Internal Relations
Relational properties are clearly not essential to substances [Macdonald,C]
     Full Idea: In statements attributing relational properties ('Felix is my favourite cat'), it seems clear that the property truly attributed to the substance is not essential to it.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: A fairly obvious point, but an important one when mapping out (cautiously) what we actually mean by 'property'. However, maybe the relational property is essential: the ceiling is ('is' of predication!) above the room.
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
Being taller is an external relation, but properties and substances have internal relations [Macdonald,C]
     Full Idea: The relation of being taller than is an external relation, since it relates two independent material substances, but the relation of instantiation or exemplification is internal, in that it relates a substance with a property.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: An interesting revival of internal relations. To be plausible it would need clear notions of 'property' and 'substance'. We are getting a long way from physics, and I sense Ockham stropping his Razor. How do you individuate a 'relation'?
8. Modes of Existence / B. Properties / 12. Denial of Properties
Does the knowledge of each property require an infinity of accompanying knowledge? [Macdonald,C]
     Full Idea: An object's being two inches long seems to guarantee an infinite number of other properties, such as being less than three inches long. If we must understand the second property to understand the first, then there seems to be a vicious infinite regress.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.2)
     A reaction: She dismisses this by saying that we don't need to know an infinity of numbers in order to count. I would say that we just need to distinguish between intrinsic and relational properties. You needn't know all a thing's relations to know the thing.
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Tropes are abstract (two can occupy the same place), but not universals (they have locations) [Macdonald,C]
     Full Idea: Tropes are abstract entities, at least in the sense that more than one can be in the same place at the same time (e.g. redness and roundness). But they are not universals, because they have unique and particular locations.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: I'm uneasy about the reification involved in this kind of talk. Does a coin possess a thing called 'roundness', which then has to be individuated, identified and located? I am drawn to the two extreme views, and suspicious of compromise.
Properties are sets of exactly resembling property-particulars [Macdonald,C]
     Full Idea: Trope Nominalism says properties are classes or sets of exactly similar or resembling tropes, where tropes are what we might called 'property-tokens' or 'particularized properties'.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: We still seem to have the problem of 'resembling' here, and we certainly have the perennial problem of why any given particular should be placed in any particular set. See Idea 7959.
Tropes are abstract particulars, not concrete particulars, so the theory is not nominalist [Macdonald,C]
     Full Idea: Trope 'Nominalism' is not a version of nominalism, because tropes are abstract particulars, rather than concrete particulars. Of course, a trope account of the relations between particulars and their properties has ramifications for concrete particulars.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6 n16)
     A reaction: Cf. Idea 7971. At this point the boundary between nominalist and realist theories seems to blur. Possibly that is bad news for tropes. Not many dilemmas can be solved by simply blurring the boundary.
8. Modes of Existence / B. Properties / 13. Tropes / b. Critique of tropes
How do a group of resembling tropes all resemble one another in the same way? [Macdonald,C]
     Full Idea: The problem is how a group of resembling tropes can be of the same type, that is, that they can resemble one another in the same way. This problem is not settled simply by positing tropes.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: There seems to be a fundamental fact that there is no resemblance unless the respect of resemblance is specified. Two identical objects could still said to be different because of their locations. Is resemblance natural or conventional? Consider atoms.
Trope Nominalism is the only nominalism to introduce new entities, inviting Ockham's Razor [Macdonald,C]
     Full Idea: Of all the nominalist solutions, Trope Nominalism is the only one that tries to solve the problem at issue by introducing entities; all the others try to get by with concrete particulars and sets of them. This might invite Ockham's Razor.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: We could reply that tropes are necessities. The issue seems to be a key one, which is whether our fundamental onotology should include properties (in some form or other). I am inclined to exclude them (Ideas 3322, 3906, 4029).
8. Modes of Existence / D. Universals / 2. Need for Universals
Numerical sameness is explained by theories of identity, but what explains qualitative identity? [Macdonald,C]
     Full Idea: We can distinguish between numerical identity and qualitative identity. Numerical sameness is explained by a theory of identity, but what explains qualitative sameness?
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: The distinction is between type and token identity. Tokens are particulars, and types are sets, so her question comes down to the one of what entitles something to be a member of a set? Nothing, if sets are totally conventional, but they aren't.
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
How can universals connect instances, if they are nothing like them? [Macdonald,C]
     Full Idea: The 'one over many' problem is to explain how universals can unify their instances if they are wholly other than them.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: If universals are self-predicating (beauty is beautiful) then they have a massive amount in common, despite one being general. You then have the regress problem of explaining the beauty of the beautiful. Baffling regress, or baffling participation.
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Real Nominalism is only committed to concrete particulars, word-tokens, and (possibly) sets [Macdonald,C]
     Full Idea: All real forms of Nominalism should hold that the only objects relevant to the explanation of generality are concrete particulars, words (i.e. word-tokens, not word-types), and perhaps sets.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6 n16)
     A reaction: The addition of sets seems controversial (see Idea 7970). The context is her rejection of the use of tropes in nominalist theories. I would doubt whether a theory still counted as nominalist if it admitted sets (e.g. Quine).
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
Resemblance Nominalism cannot explain either new resemblances, or absence of resemblances [Macdonald,C]
     Full Idea: Resemblance Nominalism cannot explain the fact that we know when and in what way new objects resemble old ones, and that we know when and in what ways new objects do not resemble old ones.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: It is not clear what sort of theory would be needed to 'explain' such a thing. Unless there is an explanation of resemblance waiting in the wings (beyond asserting that resemblance is a universal), then this is not a strong objection.
9. Objects / A. Existence of Objects / 5. Individuation / c. Individuation by location
A 'thing' cannot be in two places at once, and two things cannot be in the same place at once [Macdonald,C]
     Full Idea: The so-called 'laws of thinghood' govern particulars, saying that one thing cannot be wholly present at different places at the same time, and two things cannot occupy the same place at the same time.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.6)
     A reaction: Is this an empirical observation, or a tautology? Or might it even be a priori synthetic? What happens when two water drops or clouds merge? Or an amoeba fissions? In what sense is an image in two places at once? Se also Idea 2351.
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
We 'individuate' kinds of object, and 'identify' particular specimens [Macdonald,C]
     Full Idea: We can usefully refer to 'individuation conditions', to distinguish objects of that kind from objects not of that kind, and to 'identity conditions', to distinguish objects within that kind from one another.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.2)
     A reaction: So we individuate types or sets, and identify tokens or particulars. Sounds good. Should be in every philosopher's toolkit, and on every introductory philosophy course.
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
Unlike bundles of properties, substances have an intrinsic unity [Macdonald,C]
     Full Idea: Substances have a kind of unity that mere collocations of properties do not have, namely an instrinsic unity. So substances cannot be collocations - bundles - of properties.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: A team is a unity. Compare a similar thought, Idea 1395, about personal identity. How can something which is a pure unity have more than one property? What distinguishes substances? Why can't a substance have a certain property?
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
The bundle theory of substance implies the identity of indiscernibles [Macdonald,C]
     Full Idea: The bundle theory of substance requires unconditional commitment to the truth of the Principle of the Identity of Indiscernibles: that things that are alike with respect to all of their properties are identical.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: Since the identity of indiscernibles is very dubious (see Ideas 1365, 4476, 5746, 7928), this is bad news for the bundle theory. I suspect that all of these problems arise because no one seems to have a clear concept of a property.
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
A phenomenalist cannot distinguish substance from attribute, so must accept the bundle view [Macdonald,C]
     Full Idea: Commitment to the view that only what can be an object of possible sensory experience can exist eliminates the possibility of distinguishing between substance and attribute, leaving only one alternative, namely the bundle view.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: Phenomenalism strikes me as a paradigm case of confusing ontology with epistemology. Presumably physicists (even empiricist ones) are committed to the 'interior' of quarks and electrons, but no one expects to experience them.
When we ascribe a property to a substance, the bundle theory will make that a tautology [Macdonald,C]
     Full Idea: The bundle theory makes all true statements ascribing properties to substances uninformative, by making them logical truths. The property of being a feline animal is literally a constituent of a cat.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: The solution would seem to a distinction between accidental and essential properties. Compare 'that plane is red' with 'that plane has wings'. 'Of course it does - it's a plane'. We might still survive without a plane-substance.
Substances persist through change, but the bundle theory says they can't [Macdonald,C]
     Full Idea: Substances are capable of persisting through change, where this involves change in properties; but the bundle theory has the consequence that substances cannot survive change.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: Her example is an apple remaining an apple when it turns brown. It doesn't look, though, as if there is a precise moment when the apple-substance ceases. The end of an apple seems to be more a matter of a loss of crucial properties.
A substance might be a sequence of bundles, rather than a single bundle [Macdonald,C]
     Full Idea: Maybe a substance is not itself a bundle of properties, but a sum or sequence of bundles of properties, a bundle of bundles of properties (which 'perdures' rather than 'endures').
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: There remains the problem of deciding when the bundle has drifted too far away from the original to perdure correctly. A caterpillar can turn into a butterfly (which is pretty bizarre!), but not into a cathedral. Why? She says this idea denies change.
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
A statue and its matter have different persistence conditions, so they are not identical [Macdonald,C]
     Full Idea: Because a statue and the lump of matter that constitute it have different persistence conditions, they are not identical.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.4)
     A reaction: Maybe being a statue is a relational property? All the relational properties of a thing will have different persistence conditions. Suppose I see a face in a bowl of sugar, and you don't?
9. Objects / C. Structure of Objects / 7. Substratum
A substance is either a bundle of properties, or a bare substratum, or an essence [Macdonald,C]
     Full Idea: The three main theories of substance are the bundle theory (Leibniz, Berkeley, Hume, Ayer), the bare substratum theory (Locke and Bergmann), and the essentialist theory.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: Macdonald defends the essentialist theory. The essentialist view immediately appeals to me. Properties must be OF something, and the something must have the power to produce properties. So there.
Each substance contains a non-property, which is its substratum or bare particular [Macdonald,C]
     Full Idea: A rival to the bundle theory says that, for each substance, there is a constituent of it that is not a property but is both essential and unique to it, this constituent being referred to as a 'bare particular' or 'substratum'.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: This doesn't sound promising. It is unclear what existence devoid of all properties could be like. How could it 'have' its properties if it was devoid of features (it seems to need property-hooks)? It is an ontological black hole. How do you prove it?
The substratum theory explains the unity of substances, and their survival through change [Macdonald,C]
     Full Idea: If there is a substratum or bare particular within a substance, this gives an explanation of the unity of substances, and it is something which can survive intact when a substance changes.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: [v. compressed wording] Many problems here. The one that strikes me is that when things change they sometimes lose their unity and identity, and that seems to be decided entirely from observation of properties, not from assessing the substratum.
A substratum has the quality of being bare, and they are useless because indiscernible [Macdonald,C]
     Full Idea: There seems to be no way of identifying a substratum as the bearer of qualities without qualifiying it as bare (having the property of being bare?), ..and they cannot be used to individuate things, because they are necessarily indiscernible.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.3)
     A reaction: The defence would probably be a priori, claiming an axiomatic necessity for substrata in our thinking about the world, along with a denial that bareness is a property (any more than not being a contemporary of Napoleon is a property).
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
An object is identical with itself, and no different indiscernible object can share that [Russell/Whitehead, by Adams,RM]
     Full Idea: Trivially, the Identity of Indiscernibles says that two individuals, Castor and Pollux, cannot have all properties in common. For Castor must have the properties of being identical with Castor and not being identical with Pollux, which Pollux can't share.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913], I p.57) by Robert Merrihew Adams - Primitive Thisness and Primitive Identity 2
     A reaction: I suspect that either the property of being identical with itself is quite vacuous, or it is parasytic on primitive identity, or it is the criterion which is actually used to define identity. Either way, I don't find this claim very illuminating.
At different times Leibniz articulated three different versions of his so-called Law [Macdonald,C]
     Full Idea: There are three distinct versions of Leibniz's Law, all traced to remarks made by Leibniz: the Identity of Indiscernibles (same properties, same thing), the Indiscernibility of Identicals (same thing, same properties), and the Substitution Principle.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.2)
     A reaction: The best view seems to be to treat the second one as Leibniz's Law (and uncontroversially true), and the first one as being an interesting but dubious claim.
The Identity of Indiscernibles is false, because it is not necessarily true [Macdonald,C]
     Full Idea: One common argument to the conclusion that the Principle of the Identity of Indiscernibles is false is that it is not necessarily true.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.2 n32)
     A reaction: This sounds like a good argument. If you test the Principle with an example ('this butler is the murderer') then total identity does not seem to necessitate identity, though it strongly implies it (the butler may have a twin etc).
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
Russell showed, through the paradoxes, that our basic logical intuitions are self-contradictory [Russell/Whitehead, by Gödel]
     Full Idea: By analyzing the paradoxes to which Cantor's set theory had led, ..Russell brought to light the amazing fact that our logical intuitions (concerning such notions as truth, concept, being, class) are self-contradictory.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Kurt Gödel - Russell's Mathematical Logic p.452
     A reaction: The main intuition that failed was, I take it, that every concept has an extension, that is, there are always objects which will or could fall under the concept.
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
In continuity, what matters is not just the beginning and end states, but the process itself [Macdonald,C]
     Full Idea: What matters to continuity is not just the beginning and end states of the process by which a thing persists, perhaps through change, but the process itself.
     From: Cynthia Macdonald (Varieties of Things [2005], Ch.4)
     A reaction: This strikes me as being a really important insight. Compare Idea 4931. If this is the key to understanding mind and personal identity, it means that the concept of a 'process' must be a central issue in ontology. How do you individuate a process?
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
The multiple relations theory says assertions about propositions are about their ingredients [Russell/Whitehead, by Linsky,B]
     Full Idea: The multiple relations theory of judgement proposes that assertions about propositions are dependent upon genuine facts involving belief and other attitude relations, subjects of those attitudes, and the constituents of the belief.
     From: report of B Russell/AN Whitehead (Principia Mathematica [1913]) by Bernard Linsky - Russell's Metaphysical Logic 7.2
     A reaction: This seems to require a commitment to universals (especially relations) with which we can be directly acquainted. I prefer propositions, but as mental entities, not platonic entities.
A judgement is a complex entity, of mind and various objects [Russell/Whitehead]
     Full Idea: When a judgement occurs, there is a certain complex entity, composed of the mind and the various objects of the judgement.
     From: B Russell/AN Whitehead (Principia Mathematica [1913], p.44)
     A reaction: This is Russell's multiple-relation theory of judgement, which replaced his earlier belief in unified propositions (now 'false abstractions'). He seems to have accepted Locke's view, that the act of judgement produces the unity.
The meaning of 'Socrates is human' is completed by a judgement [Russell/Whitehead]
     Full Idea: When I judge 'Socrates is human', the meaning is completed by the act of judging.
     From: B Russell/AN Whitehead (Principia Mathematica [1913], p.44), quoted by Michael Morris - Guidebook to Wittgenstein's Tractatus
     A reaction: Morris says this is Russell's multiple-relations theory of judgement. The theory accompanies the rejection of the concept of the unified proposition. When I hear 'Socrates had a mole on his shoulder' I get the meaning without judging.
The multiple relation theory of judgement couldn't explain the unity of sentences [Morris,M on Russell/Whitehead]
     Full Idea: When Russell moved to his multiple relation theory of judgement …he then faced difficulties making sense of the unity of sentences.
     From: comment on B Russell/AN Whitehead (Principia Mathematica [1913], p.44) by Michael Morris - Guidebook to Wittgenstein's Tractatus 3A
     A reaction: Roughly, he seems committed to saying that there is only unity if you think there is unity; there is no unity in a sentence prior to the act of judgement.
Only the act of judging completes the meaning of a statement [Russell/Whitehead]
     Full Idea: When I judge 'Socrates is human', the meaning is completed by the act of judging, and we no longer have an incomplete symbol.
     From: B Russell/AN Whitehead (Principia Mathematica [1913], p.44), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap
     A reaction: Personally I would have thought that you needed to know the meaning properly before you could make the judgement, but then he is Bertrand Russell and I'm not.
19. Language / D. Propositions / 3. Concrete Propositions
Propositions as objects of judgement don't exist, because we judge several objects, not one [Russell/Whitehead]
     Full Idea: A 'proposition', in the sense in which a proposition is supposed to be the object of a judgement, is a false abstraction, because a judgement has several objects, not one.
     From: B Russell/AN Whitehead (Principia Mathematica [1913], p.44), quoted by Michael Morris - Guidebook to Wittgenstein's Tractatus 2E
     A reaction: This is the rejection of the 'Russellian' theory of propositions, in favour of his multiple-relations theory of judgement. But why don't the related objects add up to a proposition about a state of affairs?