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All the ideas for 'Powers', 'Lectures on the Philosophy of Right' and 'The Principles of Mathematics'

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133 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Substantive metaphysics says what a property is, not what a predicate means [Molnar]
     Full Idea: The motto of what is presented here is 'less conceptual analysis, more metaphysics', where the distinction is equivalent to the distinction between saying what 'F' means and saying what being F is.
     From: George Molnar (Powers [1998], 1.1)
     A reaction: This seems to me to capture exactly the spirit of metaphysics since Saul Kripke's work, though some people engaged in it seem to me to be trapped in an outdated linguistic view of the matter. Molnar credits Locke as the source of his view.
1. Philosophy / F. Analytic Philosophy / 1. Nature of Analysis
Analysis gives us nothing but the truth - but never the whole truth [Russell]
     Full Idea: Though analysis gives us the truth, and nothing but the truth, yet it can never give us the whole truth
     From: Bertrand Russell (The Principles of Mathematics [1903], §138)
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
The study of grammar is underestimated in philosophy [Russell]
     Full Idea: The study of grammar, in my opinion, is capable of throwing far more light on philosophical questions than is commonly supposed by philosophers.
     From: Bertrand Russell (The Principles of Mathematics [1903], §046)
     A reaction: This is a dangerous tendency, which has led to some daft linguistic philosophy, but Russell himself was never guilty of losing the correct perspective on the matter.
1. Philosophy / F. Analytic Philosophy / 7. Limitations of Analysis
Analysis falsifies, if when the parts are broken down they are not equivalent to their sum [Russell]
     Full Idea: It is said that analysis is falsification, that the complex is not equivalent to the sum of its constituents and is changed when analysed into these.
     From: Bertrand Russell (The Principles of Mathematics [1903], §439)
     A reaction: Not quite Moore's Paradox of Analysis, but close. Russell is articulating the view we now call 'holism' - that the whole is more than the sum of its parts - which I can never quite believe.
2. Reason / D. Definition / 4. Real Definition
A real definition gives all the properties that constitute an identity [Molnar]
     Full Idea: A real definition expresses the sum of the properties that constitute the identity of the thing defined.
     From: George Molnar (Powers [1998], 1.4.4)
     A reaction: This is a standard modern view among modern essentialists, and one which I believe can come into question. It seems to miss out the fact that an essence will also explain the possible functions and behaviours of a thing. Explanation seems basic.
2. Reason / D. Definition / 13. Against Definition
Definition by analysis into constituents is useless, because it neglects the whole [Russell]
     Full Idea: A definition as an analysis of an idea into its constituents is inconvenient and, I think, useless; it overlooks the fact that wholes are not, as a rule, determinate when their constituents are given.
     From: Bertrand Russell (The Principles of Mathematics [1903], §108)
     A reaction: The influence of Leibniz seems rather strong here, since he was obsessed with explaining what creates true unities.
In mathematics definitions are superfluous, as they name classes, and it all reduces to primitives [Russell]
     Full Idea: The statement that a class is to be represented by a symbol is a definition in mathematics, and says nothing about mathematical entities. Any formula can be stated in terms of primitive ideas, so the definitions are superfluous.
     From: Bertrand Russell (The Principles of Mathematics [1903], §412)
     A reaction: [compressed wording] I'm not sure that everyone would agree with this (e.g. Kit Fine), as certain types of numbers seem to be introduced by stipulative definitions.
2. Reason / F. Fallacies / 2. Infinite Regress
Infinite regresses have propositions made of propositions etc, with the key term reappearing [Russell]
     Full Idea: In the objectionable kind of infinite regress, some propositions join to constitute the meaning of some proposition, but one of them is similarly compounded, and so ad infinitum. This comes from circular definitions, where the term defined reappears.
     From: Bertrand Russell (The Principles of Mathematics [1903], §329)
2. Reason / F. Fallacies / 8. Category Mistake / a. Category mistakes
As well as a truth value, propositions have a range of significance for their variables [Russell]
     Full Idea: Every proposition function …has, in addition to its range of truth, a range of significance, i.e. a range within which x must lie if φ(x) is to be a proposition at all, whether true or false. This is the first point of the theory of types.
     From: Bertrand Russell (The Principles of Mathematics [1903], App B:523), quoted by Ofra Magidor - Category Mistakes 1.2
     A reaction: Magidor quotes this as the origin of the idea of a 'category mistake'. It is the basis of the formal theory of types, but is highly influential in philosophy generally, especially as a criterion for ruling many propositions as 'meaningless'.
3. Truth / A. Truth Problems / 5. Truth Bearers
What is true or false is not mental, and is best called 'propositions' [Russell]
     Full Idea: I hold that what is true or false is not in general mental, and requiring a name for the true or false as such, this name can scarcely be other than 'propositions'.
     From: Bertrand Russell (The Principles of Mathematics [1903], Pref)
     A reaction: This is the Fregean and logicians' dream that that there is some fixed eternal realm of the true and the false. I think true and false concern the mental. We can talk about the 'facts' which are independent of minds, but not the 'truth'.
3. Truth / H. Deflationary Truth / 1. Redundant Truth
"The death of Caesar is true" is not the same proposition as "Caesar died" [Russell]
     Full Idea: "The death of Caesar is true" is not, I think, the same proposition as "Caesar died".
     From: Bertrand Russell (The Principles of Mathematics [1903], §478)
     A reaction: I suspect that it was this remark which provoked Ramsey into rebellion, because he couldn't see the difference. Nowadays we must talk first of conversational implicature, and then of language and metalanguage.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
The null class is a fiction [Russell]
     Full Idea: The null class is a fiction.
     From: Bertrand Russell (The Principles of Mathematics [1903], §079)
     A reaction: This does not commit him to regarding all classes as fictions - though he seems to have eventually come to believe that. The null class seems to have a role something like 'Once upon a time...' in story-telling. You can then tell truth or fiction.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets
Russell invented the naïve set theory usually attributed to Cantor [Russell, by Lavine]
     Full Idea: Russell was the inventor of the naïve set theory so often attributed to Cantor.
     From: report of Bertrand Russell (The Principles of Mathematics [1903]) by Shaughan Lavine - Understanding the Infinite I
4. Formal Logic / F. Set Theory ST / 6. Ordering in Sets
Order rests on 'between' and 'separation' [Russell]
     Full Idea: The two sources of order are 'between' and 'separation'.
     From: Bertrand Russell (The Principles of Mathematics [1903], §204)
Order depends on transitive asymmetrical relations [Russell]
     Full Idea: All order depends upon transitive asymmetrical relations.
     From: Bertrand Russell (The Principles of Mathematics [1903], §208)
4. Formal Logic / G. Formal Mereology / 1. Mereology
The part-whole relation is ultimate and indefinable [Russell]
     Full Idea: The relation of whole and part is, it would seem, an indefinable and ultimate relation, or rather several relations, often confounded, of which one at least is indefinable.
     From: Bertrand Russell (The Principles of Mathematics [1903], §135)
     A reaction: This is before anyone had produced a mathematical account of mereology (qv).
5. Theory of Logic / B. Logical Consequence / 8. Material Implication
Implication cannot be defined [Russell]
     Full Idea: A definition of implication is quite impossible.
     From: Bertrand Russell (The Principles of Mathematics [1903], §016)
It would be circular to use 'if' and 'then' to define material implication [Russell]
     Full Idea: It would be a vicious circle to define material implication as meaning that if one proposition is true, then another is true, for 'if' and 'then' already involve implication.
     From: Bertrand Russell (The Principles of Mathematics [1903], §037)
     A reaction: Hence the preference for defining it by the truth table, or as 'not-p or q'.
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
The only classes are things, predicates and relations [Russell]
     Full Idea: The only classes appear to be things, predicates and relations.
     From: Bertrand Russell (The Principles of Mathematics [1903], §440)
     A reaction: This is the first-order logic view of reality, which has begun to look incredibly impoverished in modern times. Processes certainly demand a hearing, as do modal facts.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
There seem to be eight or nine logical constants [Russell]
     Full Idea: The number of logical constants is not great: it appears, in fact, to be eight or nine.
     From: Bertrand Russell (The Principles of Mathematics [1903], §012)
     A reaction: There is, of course, lots of scope for interdefinability. No one is going to disagree greatly with his claim, so it is an interesting fact, which invites some sort of (non-platonic) explanation.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
Negations are not just reversals of truth-value, since that can happen without negation [Wittgenstein on Russell]
     Full Idea: Russell explained ¬p by saying that ¬p is true if p is false and false if p is true. But this is not an explanation of negation, for it might apply to propositions other than the negative.
     From: comment on Bertrand Russell (The Principles of Mathematics [1903]) by Ludwig Wittgenstein - Lectures 1930-32 (student notes) B XI.3
     A reaction: Presumably he is thinking of 'the light is on' and 'the light is off'. A very astute criticism, which seems to be correct. What would Russell say? Perhaps we add that negation is an 'operation' which achieves flipping of the truth-value?
5. Theory of Logic / E. Structures of Logic / 3. Constants in Logic
Constants are absolutely definite and unambiguous [Russell]
     Full Idea: A constant is something absolutely definite, concerning which there is no ambiguity whatever.
     From: Bertrand Russell (The Principles of Mathematics [1903], §006)
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Variables don't stand alone, but exist as parts of propositional functions [Russell]
     Full Idea: A variable is not any term simply, but any term as entering into a propositional function.
     From: Bertrand Russell (The Principles of Mathematics [1903], §093)
     A reaction: So we should think of variables entirely by their role, rather than as having a semantics of their own (pace Kit Fine? - though see Russell §106, p.107).
5. Theory of Logic / G. Quantification / 1. Quantification
'Any' is better than 'all' where infinite classes are concerned [Russell]
     Full Idea: The word 'any' is preferable to the word 'all' where infinite classes are concerned.
     From: Bertrand Russell (The Principles of Mathematics [1903], §284)
     A reaction: The reason must be that it is hard to quantify over 'all' of the infinite members, but it is easier to say what is true of any one of them.
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / a. Achilles paradox
The Achilles Paradox concerns the one-one correlation of infinite classes [Russell]
     Full Idea: When the Achilles Paradox is translated into arithmetical language, it is seen to be concerned with the one-one correlation of two infinite classes.
     From: Bertrand Russell (The Principles of Mathematics [1903], §321)
     A reaction: Dedekind's view of infinity (Idea 9826) shows why this results in a horrible tangle.
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / c. Burali-Forti's paradox
Russell discovered the paradox suggested by Burali-Forti's work [Russell, by Lavine]
     Full Idea: Burali-Forti didn't discover any paradoxes, though his work suggested a paradox to Russell.
     From: report of Bertrand Russell (The Principles of Mathematics [1903]) by Shaughan Lavine - Understanding the Infinite I
6. Mathematics / A. Nature of Mathematics / 2. Geometry
In geometry, Kant and idealists aimed at the certainty of the premisses [Russell]
     Full Idea: The approach to practical geometry of the idealists, and especially of Kant, was that we must be certain of the premisses on their own account.
     From: Bertrand Russell (The Principles of Mathematics [1903], §353)
Geometry throws no light on the nature of actual space [Russell]
     Full Idea: Geometry no longer throws any direct light on the nature of actual space.
     From: Bertrand Russell (The Principles of Mathematics [1903], §353)
     A reaction: This was 1903. Minkowski then contributed a geometry of space which was used in Einstein's General Theory. It looks to me as if geometry reveals the possibilities for actual space.
Pure geometry is deductive, and neutral over what exists [Russell]
     Full Idea: As a branch of pure mathematics, geometry is strictly deductive, indifferent to the choice of its premises, and to the question of whether there strictly exist such entities. It just deals with series of more than one dimension.
     From: Bertrand Russell (The Principles of Mathematics [1903], §352)
     A reaction: This seems to be the culmination of the seventeenth century reduction of geometry to algebra. Russell admits that there is also the 'study of actual space'.
In geometry, empiricists aimed at premisses consistent with experience [Russell]
     Full Idea: The approach to practical geometry of the empiricists, notably Mill, was to show that no other set of premisses would give results consistent with experience.
     From: Bertrand Russell (The Principles of Mathematics [1903], §353)
     A reaction: The modern phrase might be that geometry just needs to be 'empirically adequate'. The empiricists are faced with the possibility of more than one successful set of premisses, and the idealist don't know how to demonstrate truth.
Two points have a line joining them (descriptive), a distance (metrical), and a whole line (projective) [Russell, by PG]
     Full Idea: Two points will define the line that joins them ('descriptive' geometry), the distance between them ('metrical' geometry), and the whole of the extended line ('projective' geometry).
     From: report of Bertrand Russell (The Principles of Mathematics [1903], §362) by PG - Db (ideas)
     A reaction: [a summary of Russell's §362] Projective Geometry clearly has the highest generality, and the modern view seems to make it the master subject of geometry.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
Russell's approach had to treat real 5/8 as different from rational 5/8 [Russell, by Dummett]
     Full Idea: Russell defined the rationals as ratios of integers, and was therefore forced to treat the real number 5/8 as an object distinct from the rational 5/8.
     From: report of Bertrand Russell (The Principles of Mathematics [1903]) by Michael Dummett - Frege philosophy of mathematics 21 'Frege's'
Ordinals result from likeness among relations, as cardinals from similarity among classes [Russell]
     Full Idea: Ordinal numbers result from likeness among relations, as cardinals from similarity among classes.
     From: Bertrand Russell (The Principles of Mathematics [1903], §293)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
Some claim priority for the ordinals over cardinals, but there is no logical priority between them [Russell]
     Full Idea: It is claimed that ordinals are prior to cardinals, because they form the progression which is relevant to mathematics, but they both form progressions and have the same ordinal properties. There is nothing to choose in logical priority between them.
     From: Bertrand Russell (The Principles of Mathematics [1903], §230)
     A reaction: We have an intuitive notion of the size of a set without number, but you can't actually start counting without number, so the ordering seems to be the key to the business, which (I would have thought) points to ordinals as prior.
Ordinals presuppose two relations, where cardinals only presuppose one [Russell]
     Full Idea: Ordinals presuppose serial and one-one relations, whereas cardinals only presuppose one-one relations.
     From: Bertrand Russell (The Principles of Mathematics [1903], §232)
     A reaction: This seems to award the palm to the cardinals, for their greater logical simplicity, but I have already given the award to the ordinals in the previous idea, and I am not going back on that.
Properties of numbers don't rely on progressions, so cardinals may be more basic [Russell]
     Full Idea: The properties of number must be capable of proof without appeal to the general properties of progressions, since cardinals can be independently defined, and must be seen in a progression before theories of progression are applied to them.
     From: Bertrand Russell (The Principles of Mathematics [1903], §243)
     A reaction: Russell says there is no logical priority between ordinals and cardinals, but it is simpler to start an account with cardinals.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Ordinals are defined through mathematical induction [Russell]
     Full Idea: The ordinal numbers are defined by some relation to mathematical induction.
     From: Bertrand Russell (The Principles of Mathematics [1903], §290)
Ordinals are types of series of terms in a row, rather than the 'nth' instance [Russell]
     Full Idea: The finite ordinals may be conceived as types of series; ..the ordinal number may be taken as 'n terms in a row'; this is distinct from the 'nth', and logically prior to it.
     From: Bertrand Russell (The Principles of Mathematics [1903], §290)
     A reaction: Worth nothing, because the popular and traditional use of 'ordinal' (as in learning a foreign language) is to mean the nth instance of something, rather than a whole series.
Transfinite ordinals don't obey commutativity, so their arithmetic is quite different from basic arithmetic [Russell]
     Full Idea: Unlike the transfinite cardinals, the transfinite ordinals do not obey the commutative law, and their arithmetic is therefore quite different from elementary arithmetic.
     From: Bertrand Russell (The Principles of Mathematics [1903], §290)
For Cantor ordinals are types of order, not numbers [Russell]
     Full Idea: In his most recent article Cantor speaks of ordinals as types of order, not as numbers.
     From: Bertrand Russell (The Principles of Mathematics [1903], §298)
     A reaction: Russell likes this because it supports his own view of ordinals as classes of serial relations. It has become orthodoxy to refer to heaps of things as 'numbers' when the people who introduced them may not have seen them that way.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / f. Cardinal numbers
We aren't sure if one cardinal number is always bigger than another [Russell]
     Full Idea: We do not know that of any two different cardinal numbers one must be the greater.
     From: Bertrand Russell (The Principles of Mathematics [1903], §300)
     A reaction: This was 1903, and I don't know whether the situation has changed. I find this thought extremely mind-boggling, given that cardinals are supposed to answer the question 'how many?' Presumably they can't be identical either. See Burali-Forti.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers are a class of rational numbers (and so not really numbers at all) [Russell]
     Full Idea: Real numbers are not really numbers at all, but something quite different; ...a real number, so I shall contend, is nothing but a certain class of rational numbers. ...A segment of rationals is a real number.
     From: Bertrand Russell (The Principles of Mathematics [1903], §258)
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / b. Quantity
Some quantities can't be measured, and some non-quantities are measurable [Russell]
     Full Idea: Some quantities cannot be measured (such as pain), and some things which are not quantities can be measured (such as certain series).
     From: Bertrand Russell (The Principles of Mathematics [1903], §150)
Quantity is not part of mathematics, where it is replaced by order [Russell]
     Full Idea: Quantity, though philosophers seem to think it essential to mathematics, does not occur in pure mathematics, and does occur in many cases not amenable to mathematical treatment. The place of quantity is taken by order.
     From: Bertrand Russell (The Principles of Mathematics [1903], §405)
     A reaction: He gives pain as an example of a quantity which cannot be treated mathematically.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
Counting explains none of the real problems about the foundations of arithmetic [Russell]
     Full Idea: The process of counting gives us no indication as to what the numbers are, as to why they form a series, or as to how it is to be proved that there are n numbers from 1 to n. Hence counting is irrelevant to the foundations of arithmetic.
     From: Bertrand Russell (The Principles of Mathematics [1903], §129)
     A reaction: I take it to be the first truth in the philosophy of mathematics that if there is a system of numbers which won't do the job of counting, then that system is irrelevant. Counting always comes first.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation
We can define one-to-one without mentioning unity [Russell]
     Full Idea: It is possible, without the notion of unity, to define what is meant by one-to-one.
     From: Bertrand Russell (The Principles of Mathematics [1903], §109)
     A reaction: This is the trick which enables the Greek account of numbers, based on units, to be abandoned. But when you have arranged the boys and the girls one-to-one, you have not yet got a concept of number.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
We do not currently know whether, of two infinite numbers, one must be greater than the other [Russell]
     Full Idea: It is not at present known whether, of two different infinite numbers, one must be greater and the other less.
     From: Bertrand Russell (The Principles of Mathematics [1903], §118)
     A reaction: This must refer to cardinal numbers, as ordinal numbers have an order. The point is that the proper subset is equal to the set (according to Dedekind).
There are cardinal and ordinal theories of infinity (while continuity is entirely ordinal) [Russell]
     Full Idea: The theory of infinity has two forms, cardinal and ordinal, of which the former springs from the logical theory of numbers; the theory of continuity is purely ordinal.
     From: Bertrand Russell (The Principles of Mathematics [1903], §249)
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / b. Mark of the infinite
Infinite numbers are distinguished by disobeying induction, and the part equalling the whole [Russell]
     Full Idea: There are two differences of infinite numbers from finite: that they do not obey mathematical induction (both cardinals and ordinals), and that the whole contains a part consisting of the same number of terms (applying only to ordinals).
     From: Bertrand Russell (The Principles of Mathematics [1903], §250)
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / h. Ordinal infinity
ω names the whole series, or the generating relation of the series of ordinal numbers [Russell]
     Full Idea: The ordinal representing the whole series must be different from what represents a segment of itself, with no immediate predecessor, since the series has no last term. ω names the class progression, or generating relation of series of this class.
     From: Bertrand Russell (The Principles of Mathematics [1903], §291)
     A reaction: He is paraphrasing Cantor's original account of ω.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
You can't get a new transfinite cardinal from an old one just by adding finite numbers to it [Russell]
     Full Idea: It must not be supposed that we can obtain a new transfinite cardinal by merely adding one to it, or even by adding any finite number, or aleph-0. On the contrary, such puny weapons cannot disturb the transfinite cardinals.
     From: Bertrand Russell (The Principles of Mathematics [1903], §288)
     A reaction: If you add one, the original cardinal would be a subset of the new one, and infinite numbers have their subsets equal to the whole, so you have gone nowhere. You begin to wonder whether transfinite cardinals are numbers at all.
For every transfinite cardinal there is an infinite collection of transfinite ordinals [Russell]
     Full Idea: For every transfinite cardinal there is an infinite collection of transfinite ordinals, although the cardinal number of all ordinals is the same as or less than that of all cardinals.
     From: Bertrand Russell (The Principles of Mathematics [1903], §290)
     A reaction: Sort that one out, and you are beginning to get to grips with the world of the transfinite! Sounds like there are more ordinals than cardinals, and more cardinals than ordinals.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers
Axiom of Archimedes: a finite multiple of a lesser magnitude can always exceed a greater [Russell]
     Full Idea: The Axiom of Archimedes asserts that, given any two magnitudes of a kind, some finite multiple of the lesser exceeds the greater.
     From: Bertrand Russell (The Principles of Mathematics [1903], §168 n*)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
Russell tried to replace Peano's Postulates with the simple idea of 'class' [Russell, by Monk]
     Full Idea: What Russell tried to show [at this time] was that Peano's Postulates (based on 'zero', 'number' and 'successor') could in turn be dispensed with, and the whole edifice built upon nothing more than the notion of 'class'.
     From: report of Bertrand Russell (The Principles of Mathematics [1903]) by Ray Monk - Bertrand Russell: Spirit of Solitude Ch.4
     A reaction: (See Idea 5897 for Peano) Presumably you can't afford to lose the notion of 'successor' in the account. If you build any theory on the idea of classes, you are still required to explain why a particular is a member of that class, and not another.
Dedekind failed to distinguish the numbers from other progressions [Shapiro on Russell]
     Full Idea: Dedekind's demonstrations nowhere - not even where he comes to cardinals - involve any property distinguishing numbers from other progressions.
     From: comment on Bertrand Russell (The Principles of Mathematics [1903], p.249) by Stewart Shapiro - Philosophy of Mathematics 5.4
     A reaction: Shapiro notes that his sounds like Frege's Julius Caesar problem, of ensuring that your definition really does capture a number. Russell is objecting to mathematical structuralism.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
Denying mathematical induction gave us the transfinite [Russell]
     Full Idea: The transfinite was obtained by denying mathematical induction.
     From: Bertrand Russell (The Principles of Mathematics [1903], §310)
     A reaction: This refers to the work of Dedekind and Cantor. This raises the question (about which thinkers have ceased to care, it seems), of whether it is rational to deny mathematical induction.
Finite numbers, unlike infinite numbers, obey mathematical induction [Russell]
     Full Idea: Finite numbers obey the law of mathematical induction: infinite numbers do not.
     From: Bertrand Russell (The Principles of Mathematics [1903], §183)
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / b. Greek arithmetic
Numbers were once defined on the basis of 1, but neglected infinities and + [Russell]
     Full Idea: It used to be common to define numbers by means of 1, with 2 being 1+1 and so on. But this method was only applicable to finite numbers, made a tiresome different between 1 and the other numbers, and left + unexplained.
     From: Bertrand Russell (The Principles of Mathematics [1903], §109)
     A reaction: Am I alone in hankering after the old approach? The idea of a 'unit' is what connected numbers to the patterns of the world. Russell's approach invites unneeded platonism. + is just 'and', and infinities are fictional extrapolations. Sounds fine to me.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
Numbers are properties of classes [Russell]
     Full Idea: Numbers are to be regarded as properties of classes.
     From: Bertrand Russell (The Principles of Mathematics [1903], §109)
     A reaction: If properties are then defined extensionally as classes, you end up with numbers as classes of classes.
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
Ordinals can't be defined just by progression; they have intrinsic qualities [Russell]
     Full Idea: It is impossible that the ordinals should be, as Dedekind suggests, nothing but the terms of such relations as constitute a progression. If they are anything at all, they must be intrinsically something.
     From: Bertrand Russell (The Principles of Mathematics [1903], §242)
     A reaction: This is the obvious platonist response to the incipient doctrine of structuralism. We have a chicken-and-egg problem. Bricks need intrinsic properties to make a structure. A structure isomorphic to numbers is not thereby the numbers.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
Mathematics doesn't care whether its entities exist [Russell]
     Full Idea: Mathematics is throughout indifferent to the question whether its entities exist.
     From: Bertrand Russell (The Principles of Mathematics [1903], §434)
     A reaction: There is an 'if-thenist' attitude in this book, since he is trying to reduce mathematics to logic. Total indifference leaves the problem of why mathematics is applicable to the real world.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
Pure mathematics is the class of propositions of the form 'p implies q' [Russell]
     Full Idea: Pure mathematics is the class of all propositions of the form 'p implies q', where p and q are propositions containing one or more variables, the same in the two propositions, and neither p nor q contains any constants except logical constants.
     From: Bertrand Russell (The Principles of Mathematics [1903], §001)
     A reaction: Linnebo calls Russell's view here 'deductive structuralism'. Russell gives (§5) as an example that Euclid is just whatever is deduced from his axioms.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
For 'x is a u' to be meaningful, u must be one range of individuals (or 'type') higher than x [Russell]
     Full Idea: In his 1903 theory of types he distinguished between individuals, ranges of individuals, ranges of ranges of individuals, and so on. Each level was a type, and it was stipulated that for 'x is a u' to be meaningful, u must be one type higher than x.
     From: Bertrand Russell (The Principles of Mathematics [1903], App)
     A reaction: Russell was dissatisfied because this theory could not deal with Cantor's Paradox. Is this the first time in modern philosophy that someone has offered a criterion for whether a proposition is 'meaningful'?
In 'x is a u', x and u must be of different types, so 'x is an x' is generally meaningless [Russell, by Magidor]
     Full Idea: Russell argues that in a statement of the form 'x is a u' (and correspondingly, 'x is a not-u'), 'x must be of different types', and hence that ''x is an x' must in general be meaningless'.
     From: report of Bertrand Russell (The Principles of Mathematics [1903], App B:524) by Ofra Magidor - Category Mistakes 1.2
     A reaction: " 'Word' is a word " comes to mind, but this would be the sort of ascent to a metalanguage (to distinguish the types) which Tarski exploited. It is the simple point that a classification can't be the same as a member of the classification.
7. Existence / A. Nature of Existence / 3. Being / a. Nature of Being
Being is what belongs to every possible object of thought [Russell]
     Full Idea: Being is that which belongs to every conceivable, to every possible object of thought.
     From: Bertrand Russell (The Principles of Mathematics [1903]), quoted by Stephen Read - Thinking About Logic Ch.5
     A reaction: I take Russell's (or anyone's) attempt to distinguish two different senses of the word 'being' or 'exist' to be an umitigated metaphysical disaster.
7. Existence / A. Nature of Existence / 3. Being / b. Being and existence
Many things have being (as topics of propositions), but may not have actual existence [Russell]
     Full Idea: Numbers, the Homeric gods, relations, chimeras and four-dimensional space all have being, for if they were not entities of a kind, we could not make propositions about them. Existence, on the contrary, is the prerogative of some only amongst the beings.
     From: Bertrand Russell (The Principles of Mathematics [1903], §427)
     A reaction: This is the analytic philosophy account of being (a long way from Heidegger). Contemporary philosophy seems to be full of confusions on this, with many writers claiming existence for things which should only be awarded 'being' status.
7. Existence / A. Nature of Existence / 6. Criterion for Existence
What exists has causal relations, but non-existent things may also have them [Russell]
     Full Idea: It would seem that whatever exists at any part of time has causal relations. This is not a distinguishing characteristic of what exists, since we have seen that two non-existent terms may be cause and effect.
     From: Bertrand Russell (The Principles of Mathematics [1903], §449)
     A reaction: Presumably he means that the non-existence of something (such as a safety rail) might the cause of an event. This is a problem for Alexander's Principle, in Idea 3534. I think we could redescribe his problem cases, to save Alexander.
7. Existence / C. Structure of Existence / 4. Ontological Dependence
Ontological dependence rests on essential connection, not necessary connection [Molnar]
     Full Idea: Ontological dependence is better understood in terms of an essential connection, rather than simply a necessary connection.
     From: George Molnar (Powers [1998], 1.4.4)
     A reaction: This seems to be an important piece in the essentialist jigsaw. Apart from essentialism, I can't think of any doctrine which offers any sort of explanation of the self-evident fact of certain ontological dependencies.
7. Existence / E. Categories / 3. Proposed Categories
Four classes of terms: instants, points, terms at instants only, and terms at instants and points [Russell]
     Full Idea: Among terms which appear to exist, there are, we may say, four great classes: 1) instants, 2) points, 3) terms which occupy instants but not points, 4) terms which occupy both points and instants. Analysis cannot explain 'occupy'.
     From: Bertrand Russell (The Principles of Mathematics [1903], §437)
     A reaction: This is a massively reductive scientific approach to categorising existence. Note that it homes in on 'terms', which seems a rather linguistic approach, although Russell is cautious about such things.
The three categories in ontology are objects, properties and relations [Molnar]
     Full Idea: The ontologically fundamental categories are three in number: Objects, Properties, and Relations.
     From: George Molnar (Powers [1998], 2 Intr)
     A reaction: We need second-order logic to quantify over all of these. The challenge to this view might be that it is static, and needs the addition of processes or events. Molnar rejects facts and states of affairs.
8. Modes of Existence / A. Relations / 1. Nature of Relations
Philosophers of logic and maths insisted that a vocabulary of relations was essential [Russell, by Heil]
     Full Idea: Relations were regarded with suspicion, until philosophers working in logic and mathematics advanced reasons to doubt that we could provide anything like an adequate description of the world without developing a relational vocabulary.
     From: report of Bertrand Russell (The Principles of Mathematics [1903], Ch.26) by John Heil - Relations
     A reaction: [Heil cites Russell as the only reference] A little warning light, that philosophers describing the world managed to do without real relations, and it was only for the abstraction of logic and maths that they became essential.
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
'Reflexiveness' holds between a term and itself, and cannot be inferred from symmetry and transitiveness [Russell]
     Full Idea: The property of a relation which insures that it holds between a term and itself is called by Peano 'reflexiveness', and he has shown, contrary to what was previously believed, that this property cannot be inferred from symmetry and transitiveness.
     From: Bertrand Russell (The Principles of Mathematics [1903], §209)
     A reaction: So we might say 'this is a sentence' has a reflexive relation, and 'this is a wasp' does not. While there are plenty of examples of mental properties with this property, I'm not sure that it makes much sense of a physical object. Indexicality...
Reflexive relations are syntactically polyadic but ontologically monadic [Molnar]
     Full Idea: Reflexive relations are, and non-reflexive relations may be, monadic in the ontological sense although they are syntactically polyadic.
     From: George Molnar (Powers [1998], 1.4.5)
     A reaction: I find this a very helpful distinction, as I have never quite understood reflexive relations as 'relations', even in the most obvious cases, such as self-love or self-slaughter.
8. Modes of Existence / A. Relations / 4. Formal Relations / b. Equivalence relation
Symmetrical and transitive relations are formally like equality [Russell]
     Full Idea: Relations which are both symmetrical and transitive are formally of the nature of equality.
     From: Bertrand Russell (The Principles of Mathematics [1903], §209)
     A reaction: This is the key to the whole equivalence approach to abstraction and Frege's definition of numbers. Establish equality conditions is the nearest you can get to saying what such things are. Personally I think we can say more, by revisiting older views.
8. Modes of Existence / B. Properties / 1. Nature of Properties
If atomism is true, then all properties derive from ultimate properties [Molnar]
     Full Idea: If a priori atomism is a true theory of the world, then all properties are derivative from ultimate properties.
     From: George Molnar (Powers [1998], 1.4.1)
     A reaction: Presumably there is a physicalist metaphysic underlying this, which means that even abstract properties derive ultimately from these physical atoms. Unless we want to postulate logical atoms, or monads, or some such weird thing.
8. Modes of Existence / B. Properties / 5. Natural Properties
'Being physical' is a second-order property [Molnar]
     Full Idea: A property like 'being physical' is just a second-order property. ...It is not required as a first-order property. ...Higher-order properties earn their keep as necessity-makers.
     From: George Molnar (Powers [1998], 1.4.2)
     A reaction: I take this to be correct and very important. People who like 'abundant' properties don't make this distinction about orders (of levels of abstraction, I would say), so the whole hierarchy has an equal status in ontology, which is ridiculous.
8. Modes of Existence / B. Properties / 6. Categorical Properties
'Categorical properties' are those which are not powers [Molnar]
     Full Idea: The canonical name for a property that is a non-power is 'categorical property'.
     From: George Molnar (Powers [1998], 10.2)
     A reaction: Molnar objects that this implies that powers cannot be used categorically, and refuses to use the term. There seems to be uncertainty over whether the term refers to necessity, or to the ability to categorise. I'm getting confused myself.
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Are tropes transferable? If they are, that is a version of Platonism [Molnar]
     Full Idea: Are tropes transferable? ...If tropes are not dependent on their bearers, that is a trope-theoretic version of Platonism.
     From: George Molnar (Powers [1998], 1.4.6)
     A reaction: These are the sort of beautifully simple questions that we pay philosophers to come up with. If they are transferable, what was the loose bond which connected them? If they aren't, then what individuates them?
8. Modes of Existence / C. Powers and Dispositions / 1. Powers
A power's type-identity is given by its definitive manifestation [Molnar]
     Full Idea: A power's type-identity is given by its definitive manifestation.
     From: George Molnar (Powers [1998], 3.1)
     A reaction: Presumably there remains an I-know-not-what that lurks behind the manifestation, which is beyond our limits of cognizance. The ultimate reality of the world has to be unknowable.
Powers have Directedness, Independence, Actuality, Intrinsicality and Objectivity [Molnar]
     Full Idea: The basic features of powers are: Directedness (to some outcome); Independence (from their manifestations); Actuality (not mere possibilities); Intrinsicality (not relying on other objects) and Objectivity (rather than psychological).
     From: George Molnar (Powers [1998], 2.4)
     A reaction: [compression of his list] This offering is why Molnar's book is important, because no one else seems to get to grips with trying to pin down what a power is, and hence their role.
8. Modes of Existence / C. Powers and Dispositions / 2. Powers as Basic
The physical world has a feature very like mental intentionality [Molnar]
     Full Idea: Something very much like mental intentionality is a pervasive and ineliminable feature of the physical world.
     From: George Molnar (Powers [1998], 3.2)
     A reaction: I like this, because it offers a continuous account of mind and world. The idea that intentionality is some magic ingredient that marks off a non-physical type of reality is nonsense. See Fodor's attempts to reduce intentionality.
Dispositions and external powers arise entirely from intrinsic powers in objects [Molnar]
     Full Idea: I propose a generalization: that all dispositional and extrinsic predicates that apply to an object, do so by virtue of intrinsic powers borne by the object.
     From: George Molnar (Powers [1998], 6.3)
     A reaction: This is the clearest statement of the 'powers' view of nature, and the one with which I agree. An interesting question is whether powers or objects are more basic in our ontology. Are objects just collections of causal powers? What has the power?
The Standard Model suggest that particles are entirely dispositional, and hence are powers [Molnar]
     Full Idea: In the Standard Model of physics the fundamental physical magnitudes are represented as ones whose whole nature is exhausted by the dispositionality, ..so there is a strong presumption that the properties of subatomic particles are powers.
     From: George Molnar (Powers [1998], 8.4.3)
     A reaction: A very nice point, because it asserts not merely that we should revise our metaphysic to endorse powers, but that we are actually already operating with exactly that view, in so far as we are physicalist.
Some powers are ungrounded, and others rest on them, and are derivative [Molnar]
     Full Idea: Some powers are grounded and some are not. ...All derivative powers ultimately derive from ungrounded powers.
     From: George Molnar (Powers [1998], 8.5.2)
     A reaction: It is tempting to use the term 'property' for the derivative powers, reserving 'power' for something which is basic. Molnar makes a plausible case, though.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Dispositions can be causes, so they must be part of the actual world [Molnar]
     Full Idea: Dispositions can be causes. What is not actual cannot be a cause or any part of a cause. Merely possible events are not actual, and that makes them causally impotent. The claim that powers are causally potent has strong initial plausibility.
     From: George Molnar (Powers [1998], 5)
     A reaction: [He credits Mellor 1974 for this idea] He will need to show how dispositions can be causes (other than, presumably, being anticipated or imagined by conscious minds), which he says he will do in Ch. 12.
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / b. Dispositions and powers
If powers only exist when actual, they seem to be nomadic, and indistinguishable from non-powers [Molnar]
     Full Idea: Two arguments against Megaran Actualism are that it turns powers into nomads: they come and go, depending on whether they are being exercised or not. And it stops us from distinguishing between unexercised powers and absent powers.
     From: George Molnar (Powers [1998], 4.3.1)
     A reaction: See Idea 11938 for Megaran Actualism. Molnar takes these objections to be fairly decisive, but if the Megarans are denying the existence of latent powers, they aren't going to be bothered by nomadism or the lack of distinction.
8. Modes of Existence / D. Universals / 6. Platonic Forms / d. Forms critiques
Platonic explanations of universals actually diminish our understanding [Molnar]
     Full Idea: We understand less after a platonic explanation of universals than we understand before it was given.
     From: George Molnar (Powers [1998], 1.2)
     A reaction: That pretty much sums up my view, and it pretty well sums up my view of religion as well. I thought I understood what numbers were until Frege told me that they were abstract objects, some sort of higher-order set.
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
For nominalists, predicate extensions are inexplicable facts [Molnar]
     Full Idea: For the nominalist, belonging to the extension of a predicate is just an inexplicable ultimate fact.
     From: George Molnar (Powers [1998], 1.2)
     A reaction: I sometimes think of myself as a nominalist, but when it is summarised in Molnar's way I back off. He seem to be offering a third way, between platonic realism and nominalism. It is physical essentialist realism, I think.
Nominalists only accept first-order logic [Molnar]
     Full Idea: A nominalist will only countenance first-order logic.
     From: George Molnar (Powers [1998], 12.2.2)
     A reaction: This is because nominalist will not acknowledge properties as entities to be quantified over. Plural quantification seems to be a strategy for extending first-order logic while retaining nominalist sympathies.
9. Objects / A. Existence of Objects / 3. Objects in Thought
I call an object of thought a 'term'. This is a wide concept implying unity and existence. [Russell]
     Full Idea: Whatever may be an object of thought, or occur in a true or false proposition, or be counted as one, I call a term. This is the widest word in the philosophical vocabulary, which I use synonymously with unit, individual, entity (being one, and existing).
     From: Bertrand Russell (The Principles of Mathematics [1903], §047)
     A reaction: The claim of existence begs many questions, such as whether the non-existence of the Loch Ness Monster is an 'object' of thought.
9. Objects / A. Existence of Objects / 5. Simples
Unities are only in propositions or concepts, and nothing that exists has unity [Russell]
     Full Idea: It is sufficient to observe that all unities are propositions or propositional concepts, and that consequently nothing that exists is a unity. If, therefore, it is maintained that things are unities, we must reply that no things exist.
     From: Bertrand Russell (The Principles of Mathematics [1903], §439)
     A reaction: The point, I presume, is that you end up as a nihilist about identities (like van Inwagen and Merricks) by mistakenly thinking (as Aristotle and Leibniz did) that everything that exists needs to have something called 'unity'.
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
The only unities are simples, or wholes composed of parts [Russell]
     Full Idea: The only kind of unity to which I can attach any precise sense - apart from the unity of the absolutely simple - is that of a whole composed of parts.
     From: Bertrand Russell (The Principles of Mathematics [1903], §439)
     A reaction: This comes from a keen student of Leibniz, who was obsessed with unity. Russell leaves unaddressed the question of what turns some parts into a whole.
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
A set has some sort of unity, but not enough to be a 'whole' [Russell]
     Full Idea: In a class as many, the component terms, though they have some kind of unity, have less than is required for a whole.
     From: Bertrand Russell (The Principles of Mathematics [1903], §070)
     A reaction: This is interesting because (among many other things), sets are used to stand for numbers, but numbers are usually reqarded as wholes.
9. Objects / C. Structure of Objects / 1. Structure of an Object
Structural properties are derivate properties [Molnar]
     Full Idea: Structural properties are clear examples of derivative properties.
     From: George Molnar (Powers [1998], 1.4.3)
     A reaction: This is an important question in the debate. Presumably you can't just reduce structural properties to more basic ones, because one set of basic properties might appear in many different structures. Ellis defends structural properties in metaphysics.
There are no 'structural properties', as properties with parts [Molnar]
     Full Idea: There are no 'structural properties', if by that we mean a property that has properties as parts.
     From: George Molnar (Powers [1998], 9.1.2)
     A reaction: There do seem to be properties that result from arranging more basic properties in one way rather than another (e.g. arranging the metal in a knife to be 'sharp'). But I think Molnar is right that they are not part of basic ontology.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
The essence of a thing need not include everything that is necessarily true of it [Molnar]
     Full Idea: Pre-theoretically it does not seem to be the case that what is essential to a thing includes everything that is necessarily true of that thing.
     From: George Molnar (Powers [1998], 1.4.4)
     A reaction: This seems to me to be true. The simple point, which I take to be obvious, is that essential properties must at the very least be in some way important, whereas necessities can be trivial. I favour the idea that the essences create the necessities.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Change is obscured by substance, a thing's nature, subject-predicate form, and by essences [Russell]
     Full Idea: The notion of change is obscured by the doctrine of substance, by a thing's nature versus its external relations, and by subject-predicate form, so that things can be different and the same. Hence the useless distinction between essential and accidental.
     From: Bertrand Russell (The Principles of Mathematics [1903], §443)
     A reaction: He goes on to object to vague unconscious usage of 'essence' by modern thinkers, but allows (teasingly) that medieval thinkers may have been precise about it. It is a fact, in common life, that things can change and be the same. Explain it!
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
Terms are identical if they belong to all the same classes [Russell]
     Full Idea: Two terms are identical when the second belongs to every class to which the first belongs.
     From: Bertrand Russell (The Principles of Mathematics [1903], §026)
It at least makes sense to say two objects have all their properties in common [Wittgenstein on Russell]
     Full Idea: Russell's definition of '=' is inadequate, because according to it we cannot say that two objects have all their properties in common. (Even if this proposition is never correct, it still has a sense).
     From: comment on Bertrand Russell (The Principles of Mathematics [1903]) by Ludwig Wittgenstein - Tractatus Logico-Philosophicus 5.5302
     A reaction: This is what now seems to be a standard denial of the bizarre Leibniz claim that there never could be two things with identical properties, even, it seems, in principle. What would Leibniz made of two electrons?
10. Modality / B. Possibility / 1. Possibility
What is the truthmaker for a non-existent possible? [Molnar]
     Full Idea: What is the nature of the truthmaker for 'It is possible that p' in cases where p itself is false?
     From: George Molnar (Powers [1998], 12.2.2)
     A reaction: Molnar mentions three views: there is a different type of being for possibilia (Meinong), or possibilia exist, or possibilia are merely represented. The third view is obviously correct, though I presume possibilia to be based on actual powers.
10. Modality / B. Possibility / 9. Counterfactuals
It makes no sense to say that a true proposition could have been false [Russell]
     Full Idea: There seems to be no true proposition of which it makes sense to say that it might have been false. One might as well say that redness might have been a taste and not a colour.
     From: Bertrand Russell (The Principles of Mathematics [1903], §430), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 29 'Analy'
     A reaction: Few thinkers agree with this rejection of counterfactuals. It seems to rely on Moore's idea that true propositions are facts. It also sounds deterministic. Does 'he is standing' mean he couldn't have been sitting (at t)?
14. Science / D. Explanation / 1. Explanation / a. Explanation
Hume allows interpolation, even though it and extrapolation are not actually valid [Molnar]
     Full Idea: In his 'shade of blue' example, Hume is (sensibly) endorsing a type of reasoning - interpolation - that is widely used by rational thinkers. Too bad that interpolation and extrapolation are incurably invalid.
     From: George Molnar (Powers [1998], 7.2.3)
     A reaction: Interpolation and extrapolation are two aspects of inductive reasoning which contribute to our notion of best explanation. Empiricism has to allow at least some knowledge which goes beyond strict direct experience.
15. Nature of Minds / A. Nature of Mind / 1. Mind / a. Mind
The two ways proposed to distinguish mind are intentionality or consciousness [Molnar]
     Full Idea: There have only been two serious proposals for distinguishing mind from matter. One appeals to intentionality, as per Brentano and his medieval precursors. The other, harking back to Descartes, Locke and empiricism, uses the capacity for consciousness.
     From: George Molnar (Powers [1998], 3.5.3)
     A reaction: Personally I take both of these to be reducible, and hence have no place for 'minds' in my ontology. Focusing on Chalmers's 'Hard Question' was the shift from the intentionality view to the consciousness view which is now more popular.
15. Nature of Minds / B. Features of Minds / 4. Intentionality / a. Nature of intentionality
Physical powers like solubility and charge also have directedness [Molnar]
     Full Idea: Contrary to the Brentano Thesis, physical powers, such as solubility or electromagnetic charge, also have that direction toward something outside themselves that is typical of psychological attributes.
     From: George Molnar (Powers [1998], 3.4)
     A reaction: I think this decisively undermines any strong thesis that 'intentionality is the mark of the mental'. I take thought to be just a fancy development of the physical powers of the physical world.
17. Mind and Body / A. Mind-Body Dualism / 4. Occasionalism
Rule occasionalism says God's actions follow laws, not miracles [Molnar]
     Full Idea: Rule occasionalists (Arnauld, Bayle) say that on their view the results of God's action are the nomic regularities of nature, and not a miracle.
     From: George Molnar (Powers [1998], 6.1)
     A reaction: This is clearly more plausible that Malebranche's idea that God constantly intervenes. I take it as a nice illustration of the fact that 'laws of nature' were mainly invented by us to explain how God could control his world. Away with them!
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
Abstraction principles identify a common property, which is some third term with the right relation [Russell]
     Full Idea: The relations in an abstraction principle are always constituted by possession of a common property (which is imprecise as it relies on 'predicate'), ..so we say a common property of two terms is any third term to which both have the same relation.
     From: Bertrand Russell (The Principles of Mathematics [1903], §157)
     A reaction: This brings out clearly the linguistic approach of the modern account of abstraction, where the older abstractionism was torn between the ontology and the epistemology (that is, the parts of objects, or the appearances of them in the mind).
The principle of Abstraction says a symmetrical, transitive relation analyses into an identity [Russell]
     Full Idea: The principle of Abstraction says that whenever a relation with instances is symmetrical and transitive, then the relation is not primitive, but is analyzable into sameness of relation to some other term. ..This is provable and states a common assumption.
     From: Bertrand Russell (The Principles of Mathematics [1903], §157)
     A reaction: At last I have found someone who explains the whole thing clearly! Bertrand Russell was wonderful. See other ideas on the subject from this text, for a proper understanding of abstraction by equivalence.
A certain type of property occurs if and only if there is an equivalence relation [Russell]
     Full Idea: The possession of a common property of a certain type always leads to a symmetrical transitive relation. The principle of Abstraction asserts the converse, that such relations only spring from common properties of the above type.
     From: Bertrand Russell (The Principles of Mathematics [1903], §157)
     A reaction: The type of property is where only one term is applicable to it, such as the magnitude of a quantity, or the time of an event. So symmetrical and transitive relations occur if and only if there is a property of that type.
19. Language / D. Propositions / 1. Propositions
Proposition contain entities indicated by words, rather than the words themselves [Russell]
     Full Idea: A proposition, unless it happens to be linguistic, does not itself contain words: it contains the entities indicated by words.
     From: Bertrand Russell (The Principles of Mathematics [1903], §051)
     A reaction: Russell says in his Preface that he took over this view of propositions from G.E. Moore. They are now known as 'Russellian' propositions, which are mainly distinguished by not being mental event, but by being complexes out in the world.
19. Language / D. Propositions / 3. Concrete Propositions
If propositions are facts, then false and true propositions are indistinguishable [Davidson on Russell]
     Full Idea: Russell often treated propositions as facts, but discovered that correspondence then became useless for explaining truth, since every meaningful expression, true or false, expresses a proposition.
     From: comment on Bertrand Russell (The Principles of Mathematics [1903]) by Donald Davidson - Truth and Predication 6
     A reaction: So 'pigs fly' would have to mean pigs actually flying (which they don't). They might correspond to possible situations, but only if pigs might fly. What do you make of 'circles are square'? Russell had many a sleepless night over that.
19. Language / D. Propositions / 5. Unity of Propositions
A proposition is a unity, and analysis destroys it [Russell]
     Full Idea: A proposition is essentially a unity, and when analysis has destroyed the unity, no enumeration of constituents will restore the proposition.
     From: Bertrand Russell (The Principles of Mathematics [1903], §054)
     A reaction: The question of the 'unity of the proposition' led to a prolonged debate.
Russell said the proposition must explain its own unity - or else objective truth is impossible [Russell, by Davidson]
     Full Idea: Moore and Russell reacted strongly against the idea that the unity of the proposition depended on human acts of judgement. ...Russell decided that unless the unity is explained in terms of the proposition itself, there can be no objective truth.
     From: report of Bertrand Russell (The Principles of Mathematics [1903], p.42) by Donald Davidson - Truth and Predication 5
     A reaction: Put like this, the Russellian view strikes me as false. Effectively he is saying that a unified proposition is the same as a fact. I take a proposition to be a brain event, best labelled by Frege as a 'thought'. Thoughts may not even have parts.
24. Political Theory / A. Basis of a State / 3. Natural Values / c. Natural rights
We are only free, with rights, if we claim our freedom, and there are no natural rights [Hegel, by Houlgate]
     Full Idea: Hegel says we are only truly free, and so bearers of rights, in so far as we claim our freedom. ...So there are no merely natural rights, and animal's have no rights.
     From: report of Georg W.F.Hegel (Lectures on the Philosophy of Right [1819], p.78) by Stephen Houlgate - An Introduction to Hegel 08 'Rights'
     A reaction: If there are no natural rights, then it is hard to see how claiming a right will create it. I can't create a right to drink the best champagne. It seems particularly unjust to deny rights to people so enslaved that freedom has never occurred to them.
24. Political Theory / D. Ideologies / 5. Democracy / d. Representative democracy
Representatives by region ignores whether they care about the national interest [Hegel, by Pinkard]
     Full Idea: Selecting representatives on the basis of geography means selecting people without any regard to whether they represent the basic and important interests of the 'whole' of society.
     From: report of Georg W.F.Hegel (Lectures on the Philosophy of Right [1819]) by Terry Pinkard - German Philosophy 1760-1860 11
     A reaction: Proportional representation seems to get away from this, but that can still be arranged according to large regions. Some means is needed to prevent the whole nation from exploitation a regional minority (such as Welsh speakers).
25. Social Practice / C. Rights / 1. Basis of Rights
The absolute right is the right to have rights [Hegel]
     Full Idea: The absolute right is the right to have rights.
     From: Georg W.F.Hegel (Lectures on the Philosophy of Right [1819], p.127), quoted by Stephen Houlgate - An Introduction to Hegel 08 'Rights'
     A reaction: What a beautifully succinct and important idea! Does a foetus, or a dog, or a person in a vegetative state, or a slave, qualify?
26. Natural Theory / C. Causation / 2. Types of cause
Singular causation is prior to general causation; each aspirin produces the aspirin generalization [Molnar]
     Full Idea: I take for granted the primacy of singular causation. A singular causal state of affairs is not constituted by a generalization. 'Aspirin relieves headache' is made true by 'This/that aspirin relieves this/that headache'.
     From: George Molnar (Powers [1998], 12.1)
     A reaction: [He cites Tooley for the opposite view] I wholly agree with Molnar, and am inclined to link it with the primacy of individual essences over kind essences.
26. Natural Theory / C. Causation / 4. Naturalised causation
We should analyse causation in terms of powers, not vice versa [Molnar]
     Full Idea: Causal analyses of powers pre-empt the correct account of causation in terms of powers.
     From: George Molnar (Powers [1998], 4.2.3)
     A reaction: I think this is my preferred view. The crucial point is that powers are active, so one is not needing to add some weird 'causation' ingredient to a world which would otherwise be passive and inert. That is a relic from the interventions of God.
26. Natural Theory / C. Causation / 7. Eliminating causation
We can drop 'cause', and just make inferences between facts [Russell]
     Full Idea: On the whole it is not worthwhile preserving the word 'cause': it is enough to say, what is far less misleading, that any two configurations allow us to infer any other.
     From: Bertrand Russell (The Principles of Mathematics [1903], §460)
     A reaction: Russell spelled this out fully in a 1912 paper. This sounds like David Hume, but he prefers to talk of 'habit' rather than 'inference', which might contain a sneaky necessity.
Moments and points seem to imply other moments and points, but don't cause them [Russell]
     Full Idea: Some people would hold that two moments of time, or two points of space, imply each other's existence; yet the relation between these cannot be said to be causal.
     From: Bertrand Russell (The Principles of Mathematics [1903], §449)
     A reaction: Famously, Russell utterly rejected causation a few years after this. The example seems clearer if you say that two points or moments can imply at least one point or instant between them, without causing them.
We should analyse causation in terms of powers [Molnar]
     Full Idea: We should give up any causal analysis of powers, ..so we should try to analyse causation in terms of powers.
     From: George Molnar (Powers [1998], 8.5.3)
     A reaction: It may be hard to explain what powers are, or identify them, if you can't say that they cause things to happen. I am torn between Molnar's view, and the view that causation is primitive.
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
Causal dependence explains counterfactual dependence, not vice versa [Molnar]
     Full Idea: The counterfactual analysis is open to the Euthyphro objection: it is causal dependence that explains any counterfactual dependence rather than vice versa.
     From: George Molnar (Powers [1998], 12.1)
     A reaction: I take views like the counterfactual analysis of causation to arise from empiricists who are bizarrely reluctant to adopt plausible best explainations (such as powers and essences).
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
Science works when we assume natural kinds have essences - because it is true [Molnar]
     Full Idea: Investigations premissed on the assumption that natural kinds have essences, that in particular the fundamental natural kinds have only essential intrinsic properties, tend to be practically successful because the assumption is true.
     From: George Molnar (Powers [1998], 11.3)
     A reaction: The point is made against a pragmatist approach to the problem by Nancy Cartwright. I take the starting point for scientific essentialism to be an empirical observation, that natural kinds seem to be very very stable. See Idea 8153.
Location in space and time are non-power properties [Molnar, by Mumford]
     Full Idea: Molnar argues that some properties are non-powers, and he cites spatial location, spatial orientation, and temporal location.
     From: report of George Molnar (Powers [1998], 158-62) by Stephen Mumford - Laws in Nature 11.4
     A reaction: Although you might say an event happened 'because' of an item on this list, this doesn't feel right to me. The ability to arrest someone is a power, but being at the scene of the crime isn't. It's an opportunity for a power.
One essential property of a muon doesn't entail the others [Molnar]
     Full Idea: The muon has mass 106.2 MeV, unit negative charge, and spin a half. The electron and tauon have unit negative charge, but electrons are 200 times less massive, and tauons 17 times more massive. Its essential properties are not mutually entailing.
     From: George Molnar (Powers [1998], 2.1)
     A reaction: This rejects a popular idea of scientific essentialism, that the essence is the set of properties which entail the non-essential properties (and not vice versa), a view which I had hitherto found rather appealing.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / b. Scientific necessity
It is contingent which kinds and powers exist in the world [Molnar]
     Full Idea: It is a contingent matter that the world contains the exact natural kinds it does, and hence it is a contingent matter that it contains the very powers it does.
     From: George Molnar (Powers [1998], 10.3)
     A reaction: I take this to be correct (for all we know). It would be daft to claim that the regularities of the universe are necessarily that way, but it is not daft to say that the stuff of the universe necessitates the pattern of what happens.
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
The laws of nature depend on the powers, not the other way round [Molnar]
     Full Idea: What powers there are does not depend on what laws there are, but vice versa, what laws obtain in the world is a function of what powers are to be found in that world.
     From: George Molnar (Powers [1998], 1.4.5)
     A reaction: This old idea may well be the most important realisation of modern times. I take the 'law' view to be based on a religious view of the world (see Idea 5470). There is still room to believe in a divine creator of the bewildering underlying powers.
The laws of motion and gravitation are just parts of the definition of a kind of matter [Russell]
     Full Idea: For us, as pure mathematicians, the laws of motion and the law of gravitation are not properly laws at all, but parts of the definition of a certain kind of matter.
     From: Bertrand Russell (The Principles of Mathematics [1903], §459)
     A reaction: The 'certain kind of matter' is that which has 'mass'. Since these are paradigm cases of supposed laws, this is the beginning of the end for real laws of nature, and good riddance say I. See Mumford on this.
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Occupying a place and change are prior to motion, so motion is just occupying places at continuous times [Russell]
     Full Idea: The concept of motion is logically subsequent to that of occupying as place at a time, and also to that of change. Motion is the occupation, by one entity, of a continuous series of places at a continuous series of times.
     From: Bertrand Russell (The Principles of Mathematics [1903], §442)
     A reaction: This is Russell's famous theory of motion, which came to be called the 'At-At' theory (at some place at some time). It seems to mathematically pin down motion all right, but seems a bit short on the poetry of the thing.
27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
Force is supposed to cause acceleration, but acceleration is a mathematical fiction [Russell]
     Full Idea: A force is the supposed cause of acceleration, ...but an acceleration is a mere mathematical fiction, a number, not a physical fact.
     From: Bertrand Russell (The Principles of Mathematics [1903], §448)
     A reaction: This rests on his at-at theory of motion, in Idea 14168. I'm not sure that if I fell off a cliff I could be reassured on the way down that my acceleration was just a mathematical fiction.
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / b. Fields
Energy fields are discontinuous at the very small [Molnar]
     Full Idea: We know that all energy fields are discontinuous below the distance measured by Planck's constant h. The physical world ultimately consists of discrete objects.
     From: George Molnar (Powers [1998], 2.2)
     A reaction: This is where quantum theory clashes with relativity, since the latter holds space to be a continuum. I'm not sure about Molnar's use of the word 'objects' here.
27. Natural Reality / C. Space / 3. Points in Space
Space is the extension of 'point', and aggregates of points seem necessary for geometry [Russell]
     Full Idea: I won't discuss whether points are unities or simple terms, but whether space is an aggregate of them. ..There is no geometry without points, nothing against them, and logical reasons in their favour. Space is the extension of the concept 'point'.
     From: Bertrand Russell (The Principles of Mathematics [1903], §423)
27. Natural Reality / D. Time / 3. Parts of Time / b. Instants
Mathematicians don't distinguish between instants of time and points on a line [Russell]
     Full Idea: To the mathematician as such there is no relevant distinction between the instants of time and the points on a line.
     From: Bertrand Russell (The Principles of Mathematics [1903], §387)
     A reaction: This is the germ of the modern view of space time, which is dictated by the mathematics, rather than by our intuitions or insights into what is actually going on.
27. Natural Reality / E. Cosmology / 1. Cosmology
The 'universe' can mean what exists now, what always has or will exist [Russell]
     Full Idea: The universe is a somewhat ambiguous term: it may mean all the things that exist at a single moment, or all things that ever have existed or will exist, or the common quality of whatever exists.
     From: Bertrand Russell (The Principles of Mathematics [1903], §442)