Combining Philosophers

All the ideas for Frank Close, Robert C. Solomon and George Cantor

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93 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Wisdom needs both thought and passion, with each reflecting on the other [Solomon]
     Full Idea: Wisdom is a matter of living both thoughtfully and passionately, bringing understanding to bear on every passion and forcing every passion into the light of reflection.
     From: Robert C. Solomon (The Passions [1976], 3.4)
     A reaction: His main point is that passion is a key part of wisdom, and the idea that wisdom is cold and detached is quite false. Good point. At the very least, wise people must relate sympathetically to others.
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
Philosophy is creating an intellectual conceptual structure for life [Solomon]
     Full Idea: Philosophy is conceptual sculpture, the shaping and developing of the intellectual structures within which we live our lives.
     From: Robert C. Solomon (The Passions [1976], Intro.1)
     A reaction: Nice. I tend to see philosophy as conceptual analysis (though creating new concepts doesn't quite fit that), but the vision of creating a huge conceptual sculpture sounds good. I would call it a system. (See my book, 'Natural Ideas'!).
2. Reason / A. Nature of Reason / 1. On Reason
Reason is actually passions, guided by perspicacious reflection [Solomon]
     Full Idea: What is called 'reason' is the passions enlightened, 'illuminated' by reflection and supported by a perspicacious deliberation that the emotions in their urgency normally excluded.
     From: Robert C. Solomon (The Passions [1976], Intro.4)
     A reaction: To suggest that reason more or less is emotions strikes me as missing the point of 'perspicacious', which takes in facts outside our emotional world. We excitedly climb a cliff, then stop when we see the rocks are crumbling.
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Trying to represent curves, we study arbitrary functions, leading to the ordinals, which produces set theory [Cantor, by Lavine]
     Full Idea: The notion of a function evolved gradually from wanting to see what curves can be represented as trigonometric series. The study of arbitrary functions led Cantor to the ordinal numbers, which led to set theory.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite I
Cantor developed sets from a progression into infinity by addition, multiplication and exponentiation [Cantor, by Lavine]
     Full Idea: Cantor's development of set theory began with his discovery of the progression 0, 1, ....∞, ∞+1, ∞+2, ..∞x2, ∞x3, ...∞^2, ..∞^3, ...∞^∞, ...∞^∞^∞.....
     From: report of George Cantor (Grundlagen (Foundations of Theory of Manifolds) [1883]) by Shaughan Lavine - Understanding the Infinite VIII.2
A set is a collection into a whole of distinct objects of our intuition or thought [Cantor]
     Full Idea: A set is any collection into a whole M of definite, distinct objects m ... of our intuition or thought.
     From: George Cantor (The Theory of Transfinite Numbers [1897], p.85), quoted by James Robert Brown - Philosophy of Mathematics Ch.2
     A reaction: This is the original conception of a set, which hit trouble with Russell's Paradox. Cantor's original definition immediately invites thoughts about the status of vague objects.
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / c. Basic theorems of ST
Cantor's Theorem: for any set x, its power set P(x) has more members than x [Cantor, by Hart,WD]
     Full Idea: Cantor's Theorem says that for any set x, its power set P(x) has more members than x.
     From: report of George Cantor (works [1880]) by William D. Hart - The Evolution of Logic 1
Cantor proved that all sets have more subsets than they have members [Cantor, by Bostock]
     Full Idea: Cantor's diagonalisation argument generalises to show that any set has more subsets than it has members.
     From: report of George Cantor (works [1880]) by David Bostock - Philosophy of Mathematics 4.5
     A reaction: Thus three members will generate seven subsets. This means that 'there is no end to the series of cardinal numbers' (Bostock p.106).
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
If a set is 'a many thought of as one', beginners should protest against singleton sets [Cantor, by Lewis]
     Full Idea: Cantor taught that a set is 'a many, which can be thought of as one'. ...After a time the unfortunate beginner student is told that some classes - the singletons - have only a single member. Here is a just cause for student protest, if ever there was one.
     From: report of George Cantor (works [1880]) by David Lewis - Parts of Classes 2.1
     A reaction: There is a parallel question, almost lost in the mists of time, of whether 'one' is a number. 'Zero' is obviously dubious, but if numbers are for counting, that needs units, so the unit is the precondition of counting, not part of it.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / d. Infinite Sets
Cantor showed that supposed contradictions in infinity were just a lack of clarity [Cantor, by Potter]
     Full Idea: Cantor's theories exhibited the contradictions others had claimed to derive from the supposition of infinite sets as confusions resulting from the failure to mark the necessary distinctions with sufficient clarity.
     From: report of George Cantor (works [1880]) by Michael Potter - Set Theory and Its Philosophy Intro 1
The continuum is the powerset of the integers, which moves up a level [Cantor, by Clegg]
     Full Idea: Cantor discovered that the continuum is the powerset of the integers. While adding or multiplying infinities didn't move up a level of complexity, multiplying a number by itself an infinite number of times did.
     From: report of George Cantor (works [1880]) by Brian Clegg - Infinity: Quest to Think the Unthinkable Ch.14
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Cantor gives informal versions of ZF axioms as ways of getting from one set to another [Cantor, by Lake]
     Full Idea: Cantor gives informal versions of the axioms of ZF as ways of getting from one set to another.
     From: report of George Cantor (Later Letters to Dedekind [1899]) by John Lake - Approaches to Set Theory 1.6
     A reaction: Lake suggests that it should therefore be called CZF.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / d. Axiom of Unions III
The Axiom of Union dates from 1899, and seems fairly obvious [Cantor, by Maddy]
     Full Idea: Cantor first stated the Union Axiom in a letter to Dedekind in 1899. It is nearly too obvious to deserve comment from most commentators. Justifications usually rest on 'limitation of size' or on the 'iterative conception'.
     From: report of George Cantor (works [1880]) by Penelope Maddy - Believing the Axioms I §1.3
     A reaction: Surely someone can think of some way to challenge it! An opportunity to become notorious, and get invited to conferences.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / b. Combinatorial sets
Cantor's sets were just collections, but Dedekind's were containers [Cantor, by Oliver/Smiley]
     Full Idea: Cantor's definition of a set was a collection of its members into a whole, but within a few years Dedekind had the idea of a set as a container, enclosing its members like a sack.
     From: report of George Cantor (works [1880]) by Oliver,A/Smiley,T - What are Sets and What are they For? Intro
     A reaction: As the article goes on to show, these two view don't seem significantly different until you start to ask about the status of the null set and of singletons. I intuitively vote for Dedekind. Set theory is the study of brackets.
5. Theory of Logic / K. Features of Logics / 8. Enumerability
There are infinite sets that are not enumerable [Cantor, by Smith,P]
     Full Idea: Cantor's Theorem (1874) says there are infinite sets that are not enumerable. This is proved by his 1891 'diagonal argument'.
     From: report of George Cantor (works [1880]) by Peter Smith - Intro to Gödel's Theorems 2.3
     A reaction: [Smith summarises the diagonal argument]
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / b. Cantor's paradox
Cantor's Paradox: the power set of the universe must be bigger than the universe, yet a subset of it [Cantor, by Hart,WD]
     Full Idea: The problem of Cantor's Paradox is that the power set of the universe has to be both bigger than the universe (by Cantor's theorem) and not bigger (since it is a subset of the universe).
     From: report of George Cantor (works [1880]) by William D. Hart - The Evolution of Logic 3
     A reaction: Russell eliminates the 'universe' in his theory of types. I don't see why you can't just say that the members of the set are hypothetical rather than real, and that hypothetically the universe might contain more things than it does.
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / e. Mirimanoff's paradox
The powerset of all the cardinal numbers is required to be greater than itself [Cantor, by Friend]
     Full Idea: Cantor's Paradox says that the powerset of a set has a cardinal number strictly greater than the original set, but that means that the powerset of the set of all the cardinal numbers is greater than itself.
     From: report of George Cantor (works [1880]) by Michèle Friend - Introducing the Philosophy of Mathematics
     A reaction: Friend cites this with the Burali-Forti paradox and the Russell paradox as the best examples of the problems of set theory in the early twentieth century. Did this mean that sets misdescribe reality, or that we had constructed them wrongly?
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Cantor named the third realm between the finite and the Absolute the 'transfinite' [Cantor, by Lavine]
     Full Idea: Cantor believed he had discovered that between the finite and the 'Absolute', which is 'incomprehensible to the human understanding', there is a third category, which he called 'the transfinite'.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite III.4
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
Cantor proved the points on a plane are in one-to-one correspondence to the points on a line [Cantor, by Lavine]
     Full Idea: In 1878 Cantor published the unexpected result that one can put the points on a plane, or indeed any n-dimensional space, into one-to-one correspondence with the points on a line.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite III.1
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
Cantor took the ordinal numbers to be primary [Cantor, by Tait]
     Full Idea: Cantor took the ordinal numbers to be primary: in his generalization of the cardinals and ordinals into the transfinite, it is the ordinals that he calls 'numbers'.
     From: report of George Cantor (works [1880]) by William W. Tait - Frege versus Cantor and Dedekind VI
     A reaction: [Tait says Dedekind also favours the ordinals] It is unclear how the matter might be settled. Humans cannot give the cardinality of large groups without counting up through the ordinals. A cardinal gets its meaning from its place in the ordinals?
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / d. Natural numbers
Cantor presented the totality of natural numbers as finite, not infinite [Cantor, by Mayberry]
     Full Idea: Cantor taught us to regard the totality of natural numbers, which was formerly thought to be infinite, as really finite after all.
     From: report of George Cantor (works [1880]) by John Mayberry - What Required for Foundation for Maths? p.414-2
     A reaction: I presume this is because they are (by definition) countable.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Cantor introduced the distinction between cardinals and ordinals [Cantor, by Tait]
     Full Idea: Cantor introduced the distinction between cardinal and ordinal numbers.
     From: report of George Cantor (works [1880]) by William W. Tait - Frege versus Cantor and Dedekind Intro
     A reaction: This seems remarkably late for what looks like a very significant clarification. The two concepts coincide in finite cases, but come apart in infinite cases (Tait p.58).
Cantor showed that ordinals are more basic than cardinals [Cantor, by Dummett]
     Full Idea: Cantor's work revealed that the notion of an ordinal number is more fundamental than that of a cardinal number.
     From: report of George Cantor (works [1880]) by Michael Dummett - Frege philosophy of mathematics Ch.23
     A reaction: Dummett makes it sound like a proof, which I find hard to believe. Is the notion that I have 'more' sheep than you logically prior to how many sheep we have? If I have one more, that implies the next number, whatever that number may be. Hm.
Ordinals are generated by endless succession, followed by a limit ordinal [Cantor, by Lavine]
     Full Idea: Ordinal numbers are generated by two principles: each ordinal has an immediate successor, and each unending sequence has an ordinal number as its limit (that is, an ordinal that is next after such a sequence).
     From: report of George Cantor (Grundlagen (Foundations of Theory of Manifolds) [1883]) by Shaughan Lavine - Understanding the Infinite III.4
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / f. Cardinal numbers
A cardinal is an abstraction, from the nature of a set's elements, and from their order [Cantor]
     Full Idea: The cardinal number of M is the general idea which, by means of our active faculty of thought, is deduced from the collection M, by abstracting from the nature of its diverse elements and from the order in which they are given.
     From: George Cantor (works [1880]), quoted by Bertrand Russell - The Principles of Mathematics §284
     A reaction: [Russell cites 'Math. Annalen, XLVI, §1'] See Fine 1998 on this.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Cantor tried to prove points on a line matched naturals or reals - but nothing in between [Cantor, by Lavine]
     Full Idea: Cantor said he could show that every infinite set of points on the line could be placed into one-to-one correspondence with either the natural numbers or the real numbers - with no intermediate possibilies (the Continuum hypothesis). His proof failed.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite III.1
Cantor's diagonal argument proved you can't list all decimal numbers between 0 and 1 [Cantor, by Read]
     Full Idea: Cantor's diagonal argument showed that all the infinite decimals between 0 and 1 cannot be written down even in a single never-ending list.
     From: report of George Cantor (works [1880]) by Stephen Read - Thinking About Logic Ch.6
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
A real is associated with an infinite set of infinite Cauchy sequences of rationals [Cantor, by Lavine]
     Full Idea: Cantor's theory of Cauchy sequences defines a real number to be associated with an infinite set of infinite sequences of rational numbers.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite II.6
     A reaction: This sounds remarkably like the endless decimals we use when we try to write down an actual real number.
Irrational numbers are the limits of Cauchy sequences of rational numbers [Cantor, by Lavine]
     Full Idea: Cantor introduced irrationals to play the role of limits of Cauchy sequences of rational numbers.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite 4.2
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Irrationals and the Dedekind Cut implied infinite classes, but they seemed to have logical difficulties [Cantor, by Lavine]
     Full Idea: From the very nature of an irrational number, it seems necessary to understand the mathematical infinite thoroughly before an adequate theory of irrationals is possible. Infinite classes are obvious in the Dedekind Cut, but have logical difficulties
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite II Intro
     A reaction: Almost the whole theory of analysis (calculus) rested on the irrationals, so a theory of the infinite was suddenly (in the 1870s) vital for mathematics. Cantor wasn't just being eccentric or mystical.
It was Cantor's diagonal argument which revealed infinities greater than that of the real numbers [Cantor, by Lavine]
     Full Idea: Cantor's 1891 diagonal argument revealed there are infinitely many infinite powers. Indeed, it showed more: it shows that given any set there is another of greater power. Hence there is an infinite power strictly greater than that of the set of the reals.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite III.2
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
Cantor proposes that there won't be a potential infinity if there is no actual infinity [Cantor, by Hart,WD]
     Full Idea: What we might call 'Cantor's Thesis' is that there won't be a potential infinity of any sort unless there is an actual infinity of some sort.
     From: report of George Cantor (works [1880]) by William D. Hart - The Evolution of Logic 1
     A reaction: This idea is nicely calculated to stop Aristotle in his tracks.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
The naturals won't map onto the reals, so there are different sizes of infinity [Cantor, by George/Velleman]
     Full Idea: Cantor showed that the complete totality of natural numbers cannot be mapped 1-1 onto the complete totality of the real numbers - so there are different sizes of infinity.
     From: report of George Cantor (works [1880]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.4
Cantor needed Power Set for the reals, but then couldn't count the new collections [Cantor, by Lavine]
     Full Idea: Cantor grafted the Power Set axiom onto his theory when he needed it to incorporate the real numbers, ...but his theory was supposed to be theory of collections that can be counted, but he didn't know how to count the new collections.
     From: report of George Cantor (The Theory of Transfinite Numbers [1897]) by Shaughan Lavine - Understanding the Infinite I
     A reaction: I take this to refer to the countability of the sets, rather than the members of the sets. Lavine notes that counting was Cantor's key principle, but he now had to abandon it. Zermelo came to the rescue.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
CH: An infinite set of reals corresponds 1-1 either to the naturals or to the reals [Cantor, by Koellner]
     Full Idea: Cantor's Continuum Hypothesis (CH) says that for every infinite set X of reals there is either a one-to-one correspondence between X and the natural numbers, or between X and the real numbers.
     From: report of George Cantor (works [1880]) by Peter Koellner - On the Question of Absolute Undecidability 1.2
     A reaction: Every single writer I read defines this differently, which drives me crazy, but is also helpfully illuminating. There is a moral there somewhere.
Cantor: there is no size between naturals and reals, or between a set and its power set [Cantor, by Hart,WD]
     Full Idea: Cantor conjectured that there is no size between those of the naturals and the reals - called the 'continuum hypothesis'. The generalized version says that for no infinite set A is there a set larger than A but smaller than P(A).
     From: report of George Cantor (works [1880]) by William D. Hart - The Evolution of Logic 1
     A reaction: Thus there are gaps between infinite numbers, and the power set is the next size up from any infinity. Much discussion as ensued about whether these two can be proved.
Cantor's Continuum Hypothesis says there is a gap between the natural and the real numbers [Cantor, by Horsten]
     Full Idea: Cantor's Continuum Hypothesis states that there are no sets which are too large for there to be a one-to-one correspondence between the set and the natural numbers, but too small for there to exist a one-to-one correspondence with the real numbers.
     From: report of George Cantor (works [1880]) by Leon Horsten - Philosophy of Mathematics §5.1
The Continuum Hypothesis says there are no sets between the natural numbers and reals [Cantor, by Shapiro]
     Full Idea: Cantor's 'continuum hypothesis' is the assertion that there are no infinite cardinalities strictly between the size of the natural numbers and the size of the real numbers.
     From: report of George Cantor (works [1880]) by Stewart Shapiro - Thinking About Mathematics 2.4
     A reaction: The tricky question is whether this hypothesis can be proved.
Continuum Hypothesis: there are no sets between N and P(N) [Cantor, by Wolf,RS]
     Full Idea: Cantor's conjecture (the Continuum Hypothesis) is that there are no sets between N and P(N). The 'generalized' version replaces N with an arbitrary infinite set.
     From: report of George Cantor (works [1880]) by Robert S. Wolf - A Tour through Mathematical Logic 2.2
     A reaction: The initial impression is that there is a single gap in the numbers, like a hole in ozone layer, but the generalised version implies an infinity of gaps. How can there be gaps in the numbers? Weird.
Continuum Hypothesis: no cardinal greater than aleph-null but less than cardinality of the continuum [Cantor, by Chihara]
     Full Idea: Cantor's Continuum Hypothesis was that there is no cardinal number greater than aleph-null but less than the cardinality of the continuum.
     From: report of George Cantor (works [1880]) by Charles Chihara - A Structural Account of Mathematics 05.1
     A reaction: I have no view on this (have you?), but the proposal that there are gaps in the number sequences has to excite all philosophers.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / h. Ordinal infinity
Cantor's theory concerns collections which can be counted, using the ordinals [Cantor, by Lavine]
     Full Idea: Cantor's set theory was not of collections in some familiar sense, but of collections that can be counted using the indexes - the finite and transfinite ordinal numbers. ..He treated infinite collections as if they were finite.
     From: report of George Cantor (works [1880]) by Shaughan Lavine - Understanding the Infinite I
Cantor extended ordinals into the transfinite, and they can thus measure infinite cardinalities [Cantor, by Maddy]
     Full Idea: Cantor's second innovation was to extend the sequence of ordinal numbers into the transfinite, forming a handy scale for measuring infinite cardinalities.
     From: report of George Cantor (works [1880]) by Penelope Maddy - Naturalism in Mathematics I.1
     A reaction: Struggling with this. The ordinals seem to locate the cardinals, but in what sense do they 'measure' them?
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
Cardinality strictly concerns one-one correspondence, to test infinite sameness of size [Cantor, by Maddy]
     Full Idea: Cantor's first innovation was to treat cardinality as strictly a matter of one-to-one correspondence, so that the question of whether two infinite sets are or aren't of the same size suddenly makes sense.
     From: report of George Cantor (works [1880]) by Penelope Maddy - Naturalism in Mathematics I.1
     A reaction: It makes sense, except that all sets which are infinite but countable can be put into one-to-one correspondence with one another. What's that all about, then?
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
The 'extension of a concept' in general may be quantitatively completely indeterminate [Cantor]
     Full Idea: The author entirely overlooks the fact that the 'extension of a concept' in general may be quantitatively completely indeterminate. Only in certain cases is the 'extension of a concept' quantitatively determinate.
     From: George Cantor (Review of Frege's 'Grundlagen' [1885], 1932:440), quoted by William W. Tait - Frege versus Cantor and Dedekind
     A reaction: Cantor presumably has in mind various infinite sets. Tait is drawing our attention to the fact that this objection long precedes Russell's paradox, which made the objection more formal (a language Frege could understand!).
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem
Property extensions outstrip objects, so shortage of objects caused the Caesar problem [Cantor, by Shapiro]
     Full Idea: Cantor's theorem entails that there are more property extensions than objects. So there are not enough objects in any domain to serve as extensions for that domain. So Frege's view that numbers are objects led to the Caesar problem.
     From: report of George Cantor (works [1880]) by Stewart Shapiro - Philosophy of Mathematics 4.6
     A reaction: So the possibility that Caesar might have to be a number arises because otherwise we are threatening to run out of numbers? Is that really the problem?
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Pure mathematics is pure set theory [Cantor]
     Full Idea: Pure mathematics ...according to my conception is nothing other than pure set theory.
     From: George Cantor (works [1880], I.1), quoted by Penelope Maddy - Naturalism in Mathematics I.1
     A reaction: [an unpublished paper of 1884] So right at the beginning of set theory this claim was being made, before it was axiomatised, and so on. Zermelo endorsed the view, and it flourished unchallenged until Benacerraf (1965).
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
Cantor says that maths originates only by abstraction from objects [Cantor, by Frege]
     Full Idea: Cantor calls mathematics an empirical science in so far as it begins with consideration of things in the external world; on his view, number originates only by abstraction from objects.
     From: report of George Cantor (works [1880]) by Gottlob Frege - Grundlagen der Arithmetik (Foundations) §21
     A reaction: Frege utterly opposed this view, and he seems to have won the day, but I am rather thrilled to find the great Cantor endorsing my own intuitions on the subject. The difficulty is to explain 'abstraction'.
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
We often trust our intuitions as rational, despite their lack of reflection [Solomon]
     Full Idea: We trust certain rational 'intuitions' in ourselves which dispense with reflection but seem to follow an indisputable logic. (note: it is thought ineffable because reflection is the paradigm of rationality. It is no less rational than reflection).
     From: Robert C. Solomon (The Passions [1976], 6.4)
     A reaction: [compressed] Solomon uses the example to support that emotion is part of rationality. Since this view of intuition is more or less mine (that intuition can be knowledge, when the justification is obscure), it seems to support his claim.
15. Nature of Minds / C. Capacities of Minds / 1. Faculties
Distinguishing reason from passion is based on an archaic 'faculty' theory [Solomon]
     Full Idea: The distinction between reason and passion is based on an archaic 'faculty' psychology of the human soul.
     From: Robert C. Solomon (The Passions [1976], Intro.2)
     A reaction: I like faculties, for philosophical purposes, as explanatory tools to account for our metaphysical and conceptual framework, but this point is well made. The danger is that we impose sharp divisions, where reality is more complex.
18. Thought / A. Modes of Thought / 3. Emotions / a. Nature of emotions
I say bodily chemistry and its sensations have nothing to do with emotions [Solomon]
     Full Idea: I shall be making the claim (sujectively) that the chemistry of the body and the sensations caused by that chemistry have nothing to do with the emotions.
     From: Robert C. Solomon (The Passions [1976], 4.1)
     A reaction: Surely an unexpected stabbing pain causes fear? Isn't pain supposed to trigger appropriate emotions? That is not to say that emotions are a feature of body chemistry.
Emotions are judgements about ourselves, and our place in the world [Solomon]
     Full Idea: An emotion is a basic judgement about our Selves and our place in the world, the projection of the values and ideals, structures and mythologies
     From: Robert C. Solomon (The Passions [1976], 5.3)
     A reaction: Solomon's main theory. What about the Frege-Geach problem - that I feel emotions (and judgements) about fictions and remote events, in which my personal concerns and involvement are zero? Presumably these emotions are parasitic on his primary type?
Emotions are defined by their objects [Solomon]
     Full Idea: Direction, scope and focus set the stage, but the specific object is what defines the emotion.
     From: Robert C. Solomon (The Passions [1976], 7.3)
     A reaction: This is presumably the main distinction between an emotion and a mood. He emphasises that the objects are subjective, rather than factual.
The heart of an emotion is its judgement of values and morality [Solomon]
     Full Idea: The heart of every emotion is its value judgements, its appraisals of gain and loss, its indictment of offences and its praise of virtue, its often Manichean judgement of 'good' and 'evil'.
     From: Robert C. Solomon (The Passions [1976], 7.6)
     A reaction: He adds blame and excuse. Some of our strongest emotions can just be identifications, rather than judgements, as when we learn of someone else's triumph or disaster. On the whole I agree, though. This is important for Aristotelian virtue theory.
Emotions can be analysed under fifteen headings [Solomon]
     Full Idea: Emotions can be analysed by direction, scope/focus, object, criteria, status, evaluations, responsibility, intersubjectivity, distance, mythology, desire, power, strategy.
     From: Robert C. Solomon (The Passions [1976], 8)
     A reaction: These are the headings Solomon actually applies in his breakdown of most of the main emotions. See his book for explanations of each of them. If people say philosophy makes no progress, I'd at least point to helpful thinking of this kind.
18. Thought / A. Modes of Thought / 3. Emotions / b. Types of emotion
Some emotions are externally directed, others internally [Solomon]
     Full Idea: 'Outer-directed' emotions (such as fear) are about particular situations, objects, or other people. …The 'inner-directed' emotions (such as vanity or regret) take one's Self as their focal point.
     From: Robert C. Solomon (The Passions [1976], 7.1)
     A reaction: This is Solomon's own distinction. Some of the emotions he cites, such as vanity, seem to me more like long term virtues or vices, rather than emotions. He did say, though, that you can have emotions without feeling, such as long-term hate.
18. Thought / A. Modes of Thought / 3. Emotions / c. Role of emotions
It is only our passions which give our lives meaning [Solomon]
     Full Idea: It is our passions, and our passions alone, which provide our lives with meaning.
     From: Robert C. Solomon (The Passions [1976], Pref)
     A reaction: This presumably entails that the lives of plants have no meaning. It also seems to be rather egotistical, since it is not clear why anyone else's life should have meaning for me, if I don't directly experience their passions. Interesting, though.
Which emotions we feel depends on our sense of our own powers [Solomon]
     Full Idea: An emotion depends on an estimation of our own power. If a lover is jealous they welcome confrontation, but if they are just envious they assume impotence from the start.
     From: Robert C. Solomon (The Passions [1976], 7.12)
     A reaction: This seems particularly true of politics, where the possibility (or not) of influencing events makes a huge difference. We can picture a huge variety of emotions when a fight breaks out in public.
The passions are subjective, concerning what is important to me, rather than facts [Solomon]
     Full Idea: The passions are uniquely subjective, although they sometimes pretend to have a certain objective status. They are not concerned with the world, but with my world. They are not concerned with 'the facts', but with what is important.
     From: Robert C. Solomon (The Passions [1976], Intro.5)
     A reaction: Values pick out what is 'important'. This idea sums up Solomon's rather solipsistic view of emotions. I accept that emotions are responses, rather than objective judgements, but there is objectivity in their social dimension. Why care about politics?
Emotions are strategies for maximising our sense of dignity and self-esteem [Solomon]
     Full Idea: Every emotion is a strategy, a purposive attempt to structure our world in such a way as to maximise our sense of personal dignity and self-esteem.
     From: Robert C. Solomon (The Passions [1976], Pref)
     A reaction: This is the main thesis of Solomon's book. There doesn't seem to be much to admire in what he takes to be our chief motivation. I would put a much more social spin on it - that our underlying urge is not self-promotion, but to fit into a community.
Passions exist as emotions, moods and desires, which all generate meaning [Solomon]
     Full Idea: There are three fundamental species passions - emotions, moods, and desires. …What all passions have in common is their ability to bestow meaning to the circumstances of our lives.
     From: Robert C. Solomon (The Passions [1976], 3.2)
     A reaction: Moods are said to be 'generalised emotions', where emotions are about something, and desires add objectives. Solomon criticises rigid divisions between mental faculties and states, but it is hard to disagree with this distinction.
The Myth of the Passions says they are irrational, uncontrolled and damaging [Solomon]
     Full Idea: The Myth of the Passions says emotions are irrational forces beyond our control, disruptive and stupid, unthinking and counterproductive, against our 'better interests', and often ridiculous.
     From: Robert C. Solomon (The Passions [1976], 6.4)
     A reaction: The Myth is very unlikely to be correct, for evolutionary reasons. How could there be a selection for a mental feature which distorts truths and leads to dangerous misjudgements? Most emotions motivate us to act successfully. So why do some run wild?
18. Thought / A. Modes of Thought / 3. Emotions / d. Emotional feeling
Feeling is a superficial aspect of emotion, and may be indeterminate, or even absent [Solomon]
     Full Idea: Feeling is the ornamentation of emotion, not its essence. ...For example, what is the difference in feeling between embarrassment and shame? …We may also experience an emotion like subdued anger or envy with no feeling.
     From: Robert C. Solomon (The Passions [1976], 4.2)
     A reaction: This is very persuasive, and supports the idea that what matters in an emotion is its content, rather than its phenomenology. He adds later that we are often mistaken about our own emotions.
18. Thought / A. Modes of Thought / 3. Emotions / e. Basic emotions
There are no 'basic' emotions, only socially prevalent ones [Solomon]
     Full Idea: There are no 'basic' emotions, only those emotions which are prevalent in a particular society. This reduction to a small set makes it impossible to appreciate the richness of our emotional lives.
     From: Robert C. Solomon (The Passions [1976], 8)
     A reaction: He cites Descartes as a culprit, and John Watson's famous list of fear, dependency and rage. I think Solomon is probably right. He suggests that the lists are usually individualistic and negative. Individuals may have their private basics!
18. Thought / A. Modes of Thought / 3. Emotions / f. Emotion and reason
It is reason which needs the anchorage of passions, rather than vice versa [Solomon]
     Full Idea: It is not the passions who require the controls and rationalisations of reason. Rather, it is reason that requires the anchorage and earthy wisdom of the passions.
     From: Robert C. Solomon (The Passions [1976], Pref)
     A reaction: I like the second half of this. We don't just follow the winds of arguments; we decide into which of the many conflicting winds we should steer the rational arguments, and that needs passions. Only a fool doesn't rationally control their passions.
Dividing ourselves into confrontational reason and passion destroys our harmonious whole [Solomon]
     Full Idea: To divide the soul into reason and passion …divides us against ourselves, forcing us each to be defensively half a person, instead of a harmonious whole.
     From: Robert C. Solomon (The Passions [1976], 2.3)
     A reaction: This is the best aspect of Solomon's book. I'm not sure, though, how this works in practice. Should I allow the winds of emotion to alter the course of my reasoning, or stunt my feelings by always insisting that reason plays a part? That's too dualist!
The supposed irrationality of our emotions is often tactless or faulty expression of them [Solomon]
     Full Idea: What is often called the 'irrationality' of our emotions is rather the faulty timing or inept choice of their expressions.
     From: Robert C. Solomon (The Passions [1976], 6.4)
     A reaction: The irrationality can be pretty obvious when having a tantrum over trivia, or resenting some tiny slight, or falling in love with a dead film star. That said, his point is well made.
18. Thought / D. Concepts / 1. Concepts / a. Nature of concepts
Infinities expand the bounds of the conceivable; we explore concepts to explore conceivability [Cantor, by Friend]
     Full Idea: Cantor (in his exploration of infinities) pushed the bounds of conceivability further than anyone before him. To discover what is conceivable, we have to enquire into the concept.
     From: report of George Cantor (works [1880]) by Michèle Friend - Introducing the Philosophy of Mathematics 6.5
     A reaction: This remark comes during a discussion of Husserl's phenomenology. Intuitionists challenge Cantor's claim, and restrict what is conceivable to what is provable. Does possibility depend on conceivability?
18. Thought / E. Abstraction / 2. Abstracta by Selection
Cantor says (vaguely) that we abstract numbers from equal sized sets [Hart,WD on Cantor]
     Full Idea: Cantor thought that we abstract a number as something common to all and only those sets any one of which has as many members as any other. ...However one wants to see the logic of the inference. The irony is that set theory lays out this logic.
     From: comment on George Cantor (works [1880]) by William D. Hart - The Evolution of Logic 1
     A reaction: The logic Hart has in mind is the notion of an equivalence relation between sets. This idea sums up the older and more modern concepts of abstraction, the first as psychological, the second as logical (or trying very hard to be!). Cf Idea 9145.
We form the image of a cardinal number by a double abstraction, from the elements and from their order [Cantor]
     Full Idea: We call 'cardinal number' the general concept which, by means of our active faculty of thought, arises when we make abstraction from an aggregate of its various elements, and of their order. From this double abstraction the number is an image in our mind.
     From: George Cantor (Beitrage [1915], §1), quoted by Kit Fine - Cantorian Abstraction: Recon. and Defence Intro
     A reaction: [compressed] This is the great Cantor, creator of set theory, endorsing the traditional abstractionism which Frege and his followers so despise. Fine offers a defence of it. The Frege view is platonist, because it refuses to connect numbers to the world.
22. Metaethics / B. Value / 1. Nature of Value / d. Subjective value
Emotions are our life force, and the source of most of our values [Solomon]
     Full Idea: Emotions are the life force of the soul, the source of most of our values (not all: there is always hunger, thirst, and fatigue).
     From: Robert C. Solomon (The Passions [1976], Intro.4)
     A reaction: I am beginning to worry that Solomon's account is too individual and subjective. My personal values may derive from my emotions, but I think human and social values are based much more on objective observations and facts. We are social, not solipsists.
22. Metaethics / B. Value / 2. Values / g. Love
Lovers adopt the interests of their beloved, rather than just valuing them [Solomon]
     Full Idea: It is often said that love takes the interests of the lover as being more important than one's own; but here again we would rather say that love takes the lovers interests as its own.
     From: Robert C. Solomon (The Passions [1976], 7.9)
     A reaction: This is because he sees emotions as almost entirely self-centred, and almost never altruistic. To me the evolutionary picture suggest a more social view. Many people want the lives of their ex- to go well, without knowing their new interests.
23. Ethics / F. Existentialism / 2. Nihilism
'Absurdity' is just the result of our wrong choices in life [Solomon]
     Full Idea: The 'absurdity of life' is nothing than our own unsatisfactory choices, typically of defensiveness and resentment, competition, and 'meaningless' routines.
     From: Robert C. Solomon (The Passions [1976], Pref)
     A reaction: He seems to have Camus particularly in mind. He sees love and co-operation as the cure. I sort of agree, but somewhere in all of our minds there lurks an abyss, with the good life looking like a distraction from it.
24. Political Theory / D. Ideologies / 1. Ideology
Ideologies are mythologies which guide our actions [Solomon]
     Full Idea: Mythologies become ideologies when we play a role in them, live in them, take action and take sides.
     From: Robert C. Solomon (The Passions [1976], 6.1)
     A reaction: This may well be a sceptical American attitude to ideology, since 'mythology' implies a fiction. But I think for most of us there exists the possibility of a good ideology, which correctly points us towards a better life. Dangerous things, though!
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / b. Heat
Work degrades into heat, but not vice versa [Close]
     Full Idea: William Thomson, Lord Kelvin, declared (in 1865) the second law of thermodynamics: mechanical work inevitably tends to degrade into heat, but not vice versa.
     From: Frank Close (Theories of Everything [2017], 3 'Perpetual')
     A reaction: The basis of entropy, which makes time an essential part of physics. Might this be the single most important fact about the physical world?
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / c. Conservation of energy
First Law: energy can change form, but is conserved overall [Close]
     Full Idea: The first law of thermodynamics : energy can be changed from one form to another, but is always conserved overall.
     From: Frank Close (Theories of Everything [2017], 3 'Perpetual')
     A reaction: So we have no idea what energy is, but we know it's conserved. (Daniel Bernoulli showed the greater the mean energy, the higher the temperature. James Joule showed the quantitative equivalence of heat and work p.26-7)
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / d. Entropy
Third Law: total order and minimum entropy only occurs at absolute zero [Close]
     Full Idea: The third law of thermodynamics says that a hypothetical state of total order and minimum entropy can be attained only at the absolute zero temperature, minus 273 degrees Celsius.
     From: Frank Close (Theories of Everything [2017], 3 'Arrow')
     A reaction: If temperature is energetic movement of atoms (or whatever), then obviously zero movement is the coldest it can get. So is absolute zero an energy state, or an absence of energy? I have no idea what 'total order' means.
27. Natural Reality / B. Modern Physics / 1. Relativity / a. Special relativity
All motions are relative and ambiguous, but acceleration is the same in all inertial frames [Close]
     Full Idea: There is no absolute state of rest; only relative motions are unambiguous. Contrast this with acceleration, however, which has the same magnitude in all inertial frames.
     From: Frank Close (Theories of Everything [2017], 3 'Newton's')
     A reaction: It seems important to remember this, before we start trumpeting about the whole of physics being relative. ....But see Idea 20634!
The electric and magnetic are tightly linked, and viewed according to your own motion [Close]
     Full Idea: Electric and magnetic phenomena are profoundly intertwined; what you interpret as electric or magnetic thus depends on your own motion.
     From: Frank Close (Theories of Everything [2017], 3 'Light!')
     A reaction: This sounds like an earlier version of special relativity.
27. Natural Reality / B. Modern Physics / 1. Relativity / b. General relativity
The general relativity equations relate curvature in space-time to density of energy-momentum [Close]
     Full Idea: The essence of general relativity relates 'curvature in space-time' on one side of the equation to the 'density of momentum and energy' on the other. ...In full, Einstein required ten equations of this type.
     From: Frank Close (Theories of Everything [2017], 5 'Gravity')
     A reaction: Momentum involves mass, and energy is equivalent to mass (e=mc^2).
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / a. Electrodynamics
Photon exchange drives the electro-magnetic force [Close]
     Full Idea: The exchange of photons drives the electro-magnetic force.
     From: Frank Close (Theories of Everything [2017], 6 'Superstrings')
     A reaction: So light, which we just think of as what is visible, is a mere side-effect of the engine room of nature - the core mechanism of the whole electro-magnetic field.
Electric fields have four basic laws (two by Gauss, one by Ampère, one by Faraday) [Close]
     Full Idea: Four basic laws of electric and magnetic fields: Gauss's Law (about the flux produced by a field), Gauss's law of magnets (there can be no monopoles), Ampère's Law (fields on surfaces), and Farday's Law (accelerated magnets produce fields).
     From: Frank Close (Theories of Everything [2017], 3 'Light!')
     A reaction: [Highly compressed, for an overview. Close explains them]
Light isn't just emitted in quanta called photons - light is photons [Close]
     Full Idea: Planck had assumed that light is emitted in quanta called photons. Einstein went further - light is photons.
     From: Frank Close (Theories of Everything [2017], 3 'Light!')
     A reaction: The point is that light travels as entities which are photons, rather than the emissions being quantized packets of some other stuff.
In general relativity the energy and momentum of photons subjects them to gravity [Close]
     Full Idea: In Einstein's general theory, gravity acts also on energy and momentum, not simply on mass. For example, massless photons of light feel the gravitational attraction of the Sun and can be deflected.
     From: Frank Close (Theories of Everything [2017], 5 'Planck')
     A reaction: Ah, a puzzle solved. How come massless photons are bent by gravity?
Electro-magnetic waves travel at light speed - so light is electromagnetism! [Close]
     Full Idea: Faradays' measurements predicted the speed of electro-magnetic waves, which happened to be the speed of light, so Maxwell made an inspired leap: light is an electromagnetic wave!
     From: Frank Close (Theories of Everything [2017], 3 'Light!')
     A reaction: Put that way, it doesn't sound like an 'inspired' leap, because travelling at exactly the same speed seems a pretty good indication that they are the same sort of thing. (But I'm not denying that Maxwell was a special guy!)
In QED, electro-magnetism exists in quantum states, emitting and absorbing electrons [Close]
     Full Idea: Dirac created quantum electrodynamics (QED): the universal electro-magnetic field can exist in discreet states of energy (with photons appearing and disappearing by energy excitations. This combined classical ideas, quantum theory and special relativity.
     From: Frank Close (Theories of Everything [2017], 3 'Light!')
     A reaction: Close says this is the theory of everything in atomic structure, but not in nuclei (which needs QCD and QFD). So if there are lots of other 'fields' (e.g. gravitational, weak, strong, Higgs), how do they all fit together? Do they talk to one another?
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / b. Fields
Quantum fields contain continual rapid creation and disappearance [Close]
     Full Idea: Quantum field theory implies that the vacuum of space is filled with particles and antiparticles which bubble in and out of existence on faster and faster timescales over shorter and shorter distances.
     From: Frank Close (Theories of Everything [2017], 6 'Intro')
     A reaction: Ponder this sentence until you head aches. Existence, but not as we know it, Jim. Close says calculations in QED about the electron confirm this.
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / c. Electrons
Electrons get their mass by interaction with the Higgs field [Close]
     Full Idea: The electron gets its mass by interaction with the ubiquitous Higgs field.
     From: Frank Close (Theories of Everything [2017], 6 'Hierarchy')
     A reaction: I thought I understood mass until I read this. Is it just wrong to say the mass of a table is the 'amount of stuff' in it?
Dirac showed how electrons conform to special relativity [Close]
     Full Idea: In 1928 Paul Dirac discovered the quantum equation that describes the electron and conforms to the requirements special relativity theory.
     From: Frank Close (Theories of Everything [2017], 3 'Light!')
     A reaction: This sounds like a major step in the unification of physics. Quantum theory and General relativity remain irreconcilable.
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
Modern theories of matter are grounded in heat, work and energy [Close]
     Full Idea: The link between temperature, heat, work and energy is at the root of our historical ability to construct theories of matter, such as Newton's dynamics, while ignoring, and indeed being ignorant of - atomic dimensions.
     From: Frank Close (Theories of Everything [2017], 3 'Arrow')
     A reaction: That is, presumably, that even when you fill in the atoms, and the standard model of physics, these aspects of matter do the main explaiining (of the behaviour, rather than of the structure).
27. Natural Reality / B. Modern Physics / 5. Unified Models / a. Electro-weak unity
The Higgs field is an electroweak plasma - but we don't know what stuff it consists of [Close]
     Full Idea: In 2012 it was confirmed that we are immersed in an electroweak plasma - the Higgs field. We curently have no knowledge of what this stuff might consist of.
     From: Frank Close (Theories of Everything [2017], 4 'Higgs')
     A reaction: The second sentence has my full attention. So we don't understand a field properly until we understand the 'stuff' it is made of? So what are all the familiar fields made of? Tell me more!
27. Natural Reality / C. Space / 3. Points in Space
Cantor proved that three dimensions have the same number of points as one dimension [Cantor, by Clegg]
     Full Idea: Cantor proved that one-dimensional space has exactly the same number of points as does two dimensions, or our familiar three-dimensional space.
     From: report of George Cantor (works [1880]) by Brian Clegg - Infinity: Quest to Think the Unthinkable Ch.14
27. Natural Reality / C. Space / 6. Space-Time
Space-time is indeterminate foam over short distances [Close]
     Full Idea: At very short distances, space-time itself becomes some indeterminate foam.
     From: Frank Close (Theories of Everything [2017], 6 'Intro')
     A reaction: [see Close for a bit more detail of this weird idea]
28. God / A. Divine Nature / 2. Divine Nature
Only God is absolutely infinite [Cantor, by Hart,WD]
     Full Idea: Cantor said that only God is absolutely infinite.
     From: report of George Cantor (works [1880]) by William D. Hart - The Evolution of Logic 1
     A reaction: We are used to the austere 'God of the philosophers', but this gives us an even more austere 'God of the mathematicians'.