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All the ideas for 'The Really Hard Problem', 'Philosophy of Mathematics' and 'Introduction to Mathematical Logic'

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59 ideas

2. Reason / D. Definition / 2. Aims of Definition
Definitions should be replaceable by primitives, and should not be creative [Brown,JR]
     Full Idea: The standard requirement of definitions involves 'eliminability' (any defined terms must be replaceable by primitives) and 'non-creativity' (proofs of theorems should not depend on the definition).
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7)
     A reaction: [He cites Russell and Whitehead as a source for this view] This is the austere view of the mathematician or logician. But almost every abstract concept that we use was actually defined in a creative way.
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Post proved the consistency of propositional logic in 1921 [Walicki]
     Full Idea: A proof of the consistency of propositional logic was given by Emil Post in 1921.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], History E.2.1)
Propositional language can only relate statements as the same or as different [Walicki]
     Full Idea: Propositional language is very rudimentary and has limited powers of expression. The only relation between various statements it can handle is that of identity and difference. As are all the same, but Bs can be different from As.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 7 Intro)
     A reaction: [second sentence a paraphrase] In predicate logic you could represent two statements as being the same except for one element (an object or predicate or relation or quantifier).
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Boolean connectives are interpreted as functions on the set {1,0} [Walicki]
     Full Idea: Boolean connectives are interpreted as functions on the set {1,0}.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 5.1)
     A reaction: 1 and 0 are normally taken to be true (T) and false (F). Thus the functions output various combinations of true and false, which are truth tables.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
The empty set is useful for defining sets by properties, when the members are not yet known [Walicki]
     Full Idea: The empty set is mainly a mathematical convenience - defining a set by describing the properties of its members in an involved way, we may not know from the very beginning what its members are.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 1.1)
The empty set avoids having to take special precautions in case members vanish [Walicki]
     Full Idea: Without the assumption of the empty set, one would often have to take special precautions for the case where a set happened to contain no elements.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 1.1)
     A reaction: Compare the introduction of the concept 'zero', where special precautions are therefore required. ...But other special precautions are needed without zero. Either he pays us, or we pay him, or ...er. Intersecting sets need the empty set.
4. Formal Logic / F. Set Theory ST / 3. Types of Set / d. Infinite Sets
Set theory says that natural numbers are an actual infinity (to accommodate their powerset) [Brown,JR]
     Full Idea: The set-theory account of infinity doesn't just say that we can keep on counting, but that the natural numbers are an actual infinite set. This is necessary to make sense of the powerset of ω, as the set of all its subsets, and thus even bigger.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5)
     A reaction: I don't personally find this to be sufficient reason to commit myself to the existence of actual infinities. In fact I have growing doubts about the whole role of set theory in philosophy of mathematics. Shows how much I know.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets
Naïve set theory assumed that there is a set for every condition [Brown,JR]
     Full Idea: In the early versions of set theory ('naïve' set theory), the axiom of comprehension assumed that for any condition there is a set of objects satisfying that condition (so P(x)↔x∈{x:P(x)}), but this led directly to Russell's Paradox.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: How rarely any philosophers state this problem clearly (as Brown does here). This is incredibly important for our understanding of how we classify the world. I'm tempted to just ignore Russell, and treat sets in a natural and sensible way.
Nowadays conditions are only defined on existing sets [Brown,JR]
     Full Idea: In current set theory Russell's Paradox is avoided by saying that a condition can only be defined on already existing sets.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: A response to Idea 9613. This leaves us with no account of how sets are created, so we have the modern notion that absolutely any grouping of daft things is a perfectly good set. The logicians seem to have hijacked common sense.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The 'iterative' view says sets start with the empty set and build up [Brown,JR]
     Full Idea: The modern 'iterative' concept of a set starts with the empty set φ (or unsetted individuals), then uses set-forming operations (characterized by the axioms) to build up ever more complex sets.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: The only sets in our system will be those we can construct, rather than anything accepted intuitively. It is more about building an elaborate machine that works than about giving a good model of reality.
4. Formal Logic / F. Set Theory ST / 6. Ordering in Sets
Ordinals play the central role in set theory, providing the model of well-ordering [Walicki]
     Full Idea: Ordinals play the central role in set theory, providing the paradigmatic well-orderings.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3)
     A reaction: When you draw the big V of the iterative hierarchy of sets (built from successive power sets), the ordinals are marked as a single line up the middle, one ordinal for each level.
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
A flock of birds is not a set, because a set cannot go anywhere [Brown,JR]
     Full Idea: Neither a flock of birds nor a pack of wolves is strictly a set, since a flock can fly south, and a pack can be on the prowl, whereas sets go nowhere and menace no one.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7)
     A reaction: To say that the pack menaced you would presumably be to commit the fallacy of composition. Doesn't the number 64 have properties which its set-theoretic elements (whatever we decide they are) will lack?
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
To determine the patterns in logic, one must identify its 'building blocks' [Walicki]
     Full Idea: In order to construct precise and valid patterns of arguments one has to determine their 'building blocks'. One has to identify the basic terms, their kinds and means of combination.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], History Intro)
     A reaction: A deceptively simple and important idea. All explanation requires patterns and levels, and it is the idea of building blocks which makes such things possible. It is right at the centre of our grasp of everything.
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
If a proposition is false, then its negation is true [Brown,JR]
     Full Idea: The law of excluded middle says if a proposition is false, then its negation is true
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 1)
     A reaction: Surely that is the best statement of the law? How do you write that down? ¬(P)→¬P? No, because it is a semantic claim, not a syntactic claim, so a truth table captures it. Semantic claims are bigger than syntactic claims.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki]
     Full Idea: A specification of a domain of objects, and of the rules for interpreting the symbols of a logical language in this domain such that all the theorems of the logical theory are true is said to be a 'model' of the theory.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], History E.1.3)
     A reaction: The basic ideas of this emerged 1915-30, but it needed Tarski's account of truth to really get it going.
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki]
     Full Idea: The L-S Theorem is ...a shocking result, since it implies that any consistent formal theory of everything - even about biology, physics, sets or the real numbers - can just as well be understood as being about natural numbers. It says nothing more.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], History E.2)
     A reaction: Illuminating. Particularly the point that no theory about the real numbers can say anything more than a theory about the natural numbers. So the natural numbers contain all the truths we can ever express? Eh?????
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Axioms are either self-evident, or stipulations, or fallible attempts [Brown,JR]
     Full Idea: The three views one could adopt concerning axioms are that they are self-evident truths, or that they are arbitrary stipulations, or that they are fallible attempts to describe how things are.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch.10)
     A reaction: Presumably modern platonists like the third version, with others choosing the second, and hardly anyone now having the confidence to embrace the first.
A compact axiomatisation makes it possible to understand a field as a whole [Walicki]
     Full Idea: Having such a compact [axiomatic] presentation of a complicated field [such as Euclid's], makes it possible to relate not only to particular theorems but also to the whole field as such.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 4.1)
Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki]
     Full Idea: Axiomatic systems, their primitive terms and proofs, are purely syntactic, that is, do not presuppose any interpretation. ...[142] They never address the world directly, but address a possible semantic model which formally represents the world.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 4.1)
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / c. Berry's paradox
Berry's Paradox finds a contradiction in the naming of huge numbers [Brown,JR]
     Full Idea: Berry's Paradox refers to 'the least integer not namable in fewer than nineteen syllables' - a paradox because it has just been named in eighteen syllables.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5)
     A reaction: Apparently George Boolos used this quirky idea as a basis for a new and more streamlined proof of Gödel's Theorem. Don't tell me you don't find that impressive.
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Mathematics is the only place where we are sure we are right [Brown,JR]
     Full Idea: Mathematics seems to be the one and only place where we humans can be absolutely sure that we got it right.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 1)
     A reaction: Apart from death and taxes, that is. Personally I am more certain of the keyboard I am typing on than I am of Pythagoras's Theorem, but the experts seem pretty confident about the number stuff.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
'There are two apples' can be expressed logically, with no mention of numbers [Brown,JR]
     Full Idea: 'There are two apples' can be recast as 'x is an apple and y is an apple, and x isn't y, and if z is an apple it is the same as x or y', which makes no appeal at all to mathematics.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4)
     A reaction: He cites this as the basis of Hartry Field's claim that science can be done without numbers. The logic is ∃x∃y∀z(Ax&Ay&(x¬=y)&(Az→z=x∨z=y)).
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki]
     Full Idea: An ordinal can be defined as a transitive set of transitive sets, or else, as a transitive set totally ordered by set inclusion.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3)
Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki]
     Full Idea: The collection of ordinals is defined inductively: Basis: the empty set is an ordinal; Ind: for an ordinal x, the union with its singleton is also an ordinal; and any arbitrary (possibly infinite) union of ordinals is an ordinal.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3)
     A reaction: [symbolism translated into English] Walicki says they are called 'ordinal numbers', but are in fact a set.
The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki]
     Full Idea: We can form infinite ordinals by taking unions of ordinals. We can thus form 'limit ordinals', which have no immediate predecessor. ω is the first (the union of all finite ordinals), ω + ω = sω is second, 3ω the third....
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3)
Two infinite ordinals can represent a single infinite cardinal [Walicki]
     Full Idea: There may be several ordinals for the same cardinality. ...Two ordinals can represent different ways of well-ordering the same number (aleph-0) of elements.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3)
     A reaction: This only applies to infinite ordinals and cardinals. For the finite, the two coincide. In infinite arithmetic the rules are different.
Members of ordinals are ordinals, and also subsets of ordinals [Walicki]
     Full Idea: Every member of an ordinal is itself an ordinal, and every ordinal is a transitive set (its members are also its subsets; a member of a member of an ordinal is also a member of the ordinal).
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.3)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / n. Pi
π is a 'transcendental' number, because it is not the solution of an equation [Brown,JR]
     Full Idea: The number π is not only irrational, but it is also (unlike √2) a 'transcendental' number, because it is not the solution of an algebraic equation.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch.10)
     A reaction: So is that a superficial property, or a profound one? Answers on a post card.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / g. Applying mathematics
Mathematics represents the world through structurally similar models. [Brown,JR]
     Full Idea: Mathematics hooks onto the world by providing representations in the form of structurally similar models.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4)
     A reaction: This is Brown's conclusion. It needs notions of mapping, one-to-one correspondence, and similarity. I like the idea of a 'model', as used in both logic and mathematics, and children's hobbies. The mind is a model-making machine.
6. Mathematics / B. Foundations for Mathematics / 2. Proof in Mathematics
There is no limit to how many ways something can be proved in mathematics [Brown,JR]
     Full Idea: I'm tempted to say that mathematics is so rich that there are indefinitely many ways to prove anything - verbal/symbolic derivations and pictures are just two.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 9)
     A reaction: Brown has been defending pictures as a form of proof. I wonder how long his list would be, if we challenged him to give more details? Some people have very low standards of proof.
Computers played an essential role in proving the four-colour theorem of maps [Brown,JR]
     Full Idea: The celebrity of the famous proof in 1976 of the four-colour theorem of maps is that a computer played an essential role in the proof.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch.10)
     A reaction: The problem concerns the reliability of the computers, but then all the people who check a traditional proof might also be unreliable. Quis custodet custodies?
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki]
     Full Idea: Since non-Euclidean geometry preserves all Euclid's postulates except the fifth one, all the theorems derived without the use of the fifth postulate remain valid.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 4.1)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
Inductive proof depends on the choice of the ordering [Walicki]
     Full Idea: Inductive proof is not guaranteed to work in all cases and, particularly, it depends heavily on the choice of the ordering.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], 2.1.1)
     A reaction: There has to be an well-founded ordering for inductive proofs to be possible.
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Set theory may represent all of mathematics, without actually being mathematics [Brown,JR]
     Full Idea: Maybe all of mathematics can be represented in set theory, but we should not think that mathematics is set theory. Functions can be represented as order pairs, but perhaps that is not what functions really are.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7)
     A reaction: This seems to me to be the correct view of the situation. If 2 is represented as {φ,{φ}}, why is that asymmetrical? The first digit seems to be the senior and original partner, but how could the digits of 2 differ from one another?
When graphs are defined set-theoretically, that won't cover unlabelled graphs [Brown,JR]
     Full Idea: The basic definition of a graph can be given in set-theoretic terms,...but then what could an unlabelled graph be?
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7)
     A reaction: An unlabelled graph will at least need a verbal description for it to have any significance at all. My daily mood-swings look like this....
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / d. Platonist structuralism
To see a structure in something, we must already have the idea of the structure [Brown,JR]
     Full Idea: Epistemology is a big worry for structuralists. ..To conjecture that something has a particular structure, we must already have conceived of the idea of the structure itself; we cannot be discovering structures by conjecturing them.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4)
     A reaction: This has to be a crucial area of discussion. Do we have our heads full of abstract structures before we look out of the window? Externalism about the mind is important here; mind and world are not utterly distinct things.
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
Sets seem basic to mathematics, but they don't suit structuralism [Brown,JR]
     Full Idea: Set theory is at the very heart of mathematics; it may even be all there is to mathematics. The notion of set, however, seems quite contrary to the spirit of structuralism.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4)
     A reaction: So much the worse for sets, I say. You can, for example, define ordinality in terms of sets, but that is no good if ordinality is basic to the nature of numbers, rather than a later addition.
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
The irrationality of root-2 was achieved by intellect, not experience [Brown,JR]
     Full Idea: We could not discover irrational numbers by physical measurement. The discovery of the irrationality of the square root of two was an intellectual achievement, not at all connected to sense experience.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 1)
     A reaction: Brown declares himself a platonist, and this is clearly a key argument for him, and rather a good one. Hm. I'll get back to you on this one...
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
There is an infinity of mathematical objects, so they can't be physical [Brown,JR]
     Full Idea: A simple argument makes it clear that all mathematical arguments are abstract: there are infinitely many numbers, but only a finite number of physical entities, so most mathematical objects are non-physical. The best assumption is that they all are.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: This, it seems to me, is where constructivists score well (cf. Idea 9608). I don't have an infinity of bricks to build an infinity of houses, but I can imagine that the bricks just keep coming if I need them. Imagination is what is unbounded.
Numbers are not abstracted from particulars, because each number is a particular [Brown,JR]
     Full Idea: Numbers are not 'abstract' (in the old sense, of universals abstracted from particulars), since each of the integers is a unique individual, a particular, not a universal.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: An interesting observation which I have not seen directly stated before. Compare Idea 645. I suspect that numbers should be thought of as higher-order abstractions, which don't behave like normal universals (i.e. they're not distributed).
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Empiricists base numbers on objects, Platonists base them on properties [Brown,JR]
     Full Idea: Perhaps, instead of objects, numbers are associated with properties of objects. Basing them on objects is strongly empiricist and uses first-order logic, whereas the latter view is somewhat Platonistic, and uses second-order logic.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4)
     A reaction: I don't seem to have a view on this. You can count tomatoes, or you can count red objects, or even 'instances of red'. Numbers refer to whatever can be individuated. No individuation, no arithmetic. (It's also Hume v Armstrong on laws on nature).
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Does some mathematics depend entirely on notation? [Brown,JR]
     Full Idea: Are there mathematical properties which can only be discovered using a particular notation?
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 6)
     A reaction: If so, this would seem to be a serious difficulty for platonists. Brown has just been exploring the mathematical theory of knots.
For nomalists there are no numbers, only numerals [Brown,JR]
     Full Idea: For the instinctive nominalist in mathematics, there are no numbers, only numerals.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5)
     A reaction: Maybe. A numeral is a specific sign, sometimes in a specific natural language, so this seems to miss the fact that cardinality etc are features of reality, not just conventions.
The most brilliant formalist was Hilbert [Brown,JR]
     Full Idea: In mathematics, the most brilliant formalist of all was Hilbert
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5)
     A reaction: He seems to have developed his fully formalist views later in his career. See Mathematics|Basis of Mathematic|Formalism in our thematic section. Kreisel denies that Hilbert was a true formalist.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
There are no constructions for many highly desirable results in mathematics [Brown,JR]
     Full Idea: Constuctivists link truth with constructive proof, but necessarily lack constructions for many highly desirable results of classical mathematics, making their account of mathematical truth rather implausible.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: The tricky word here is 'desirable', which is an odd criterion for mathematical truth. Nevertheless this sounds like a good objection. How flexible might the concept of a 'construction' be?
Constructivists say p has no value, if the value depends on Goldbach's Conjecture [Brown,JR]
     Full Idea: If we define p as '3 if Goldbach's Conjecture is true' and '5 if Goldbach's Conjecture is false', it seems that p must be a prime number, but, amazingly, constructivists would not accept this without a proof of Goldbach's Conjecture.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 8)
     A reaction: A very similar argument structure to Schrödinger's Cat. This seems (as Brown implies) to be a devastating knock-down argument, but I'll keep an open mind for now.
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
David's 'Napoleon' is about something concrete and something abstract [Brown,JR]
     Full Idea: David's painting of Napoleon (on a white horse) is a 'picture' of Napoleon, and a 'symbol' of leadership, courage, adventure. It manages to be about something concrete and something abstract.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 3)
     A reaction: This strikes me as the germ of an extremely important idea - that abstraction is involved in our perception of the concrete, so that they are not two entirely separate realms. Seeing 'as' involves abstraction.
10. Modality / A. Necessity / 2. Nature of Necessity
Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki]
     Full Idea: The link between time and modality was severed by Duns Scotus, who proposed a notion of possibility based purely on the notion of semantic consistency. 'Possible' means for him logically possible, that is, not involving contradiction.
     From: Michal Walicki (Introduction to Mathematical Logic [2012], History B.4)
15. Nature of Minds / B. Features of Minds / 2. Unconscious Mind
Research suggest that we overrate conscious experience [Flanagan]
     Full Idea: The emerging consensus is that we probably overrate the power of conscious experience in our lives. Freud, of course, said the same thing for different reasons.
     From: Owen Flanagan (The Really Hard Problem [2007], 3 'Ontology')
     A reaction: [He cites Pockett, Banks and Gallagher 2006]. Freud was concerned with big deep secrets, but the modern view concerns ordinary decisions and perceptions. An important idea, which should incline us all to become Nietzscheans.
17. Mind and Body / E. Mind as Physical / 2. Reduction of Mind
Sensations may be identical to brain events, but complex mental events don't seem to be [Flanagan]
     Full Idea: There is still some hope for something like identity theory for sensations. But almost no one believes that strict identity theory will work for more complex mental states. Strict identity is stronger than type neurophysicalism.
     From: Owen Flanagan (The Really Hard Problem [2007], 3 'Ontology')
     A reaction: It is so hard to express the problem. What needs to be explained? How can one bunch of neurons represent many different things? It's not like computing. That just transfers the data to brains, where the puzzling stuff happens.
18. Thought / E. Abstraction / 1. Abstract Thought
'Abstract' nowadays means outside space and time, not concrete, not physical [Brown,JR]
     Full Idea: The current usage of 'abstract' simply means outside space and time, not concrete, not physical.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: This is in contrast to Idea 9609 (the older notion of being abstracted). It seems odd that our ancestors had a theory about where such ideas came from, but modern thinkers have no theory at all. Blame Frege for that.
The older sense of 'abstract' is where 'redness' or 'group' is abstracted from particulars [Brown,JR]
     Full Idea: The older sense of 'abstract' applies to universals, where a universal like 'redness' is abstracted from red particulars; it is the one associated with the many. In mathematics, the notion of 'group' or 'vector space' perhaps fits this pattern.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2)
     A reaction: I am currently investigating whether this 'older' concept is in fact dead. It seems to me that it is needed, as part of cognitive science, and as the crucial link between a materialist metaphysic and the world of ideas.
19. Language / A. Nature of Meaning / 7. Meaning Holism / c. Meaning by Role
A term can have not only a sense and a reference, but also a 'computational role' [Brown,JR]
     Full Idea: In addition to the sense and reference of term, there is the 'computational' role. The name '2' has a sense (successor of 1) and a reference (the number 2). But the word 'two' has little computational power, Roman 'II' is better, and '2' is a marvel.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 6)
     A reaction: Very interesting, and the point might transfer to natural languages. Synonymous terms carry with them not just different expressive powers, but the capacity to play different roles (e.g. slang and formal terms, gob and mouth).
22. Metaethics / B. Value / 1. Nature of Value / b. Fact and value
Morality is normative because it identifies best practices among the normal practices [Flanagan]
     Full Idea: Morality is 'normative' in the sense that it consists of the extraction of ''good' or 'excellent' practices from common practices.
     From: Owen Flanagan (The Really Hard Problem [2007], 4 'Naturalism')
22. Metaethics / B. Value / 2. Values / f. Altruism
For Darwinians, altruism is either contracts or genetics [Flanagan]
     Full Idea: Two explanations came forward in the neo-Darwinian synthesis. Altruism is either 1) person-based reciprocal altruism, or 2) gene-based kin altruism.
     From: Owen Flanagan (The Really Hard Problem [2007], 2 'Darwin')
     A reaction: Flanagan obviously thinks there is also 'genuine psychological atruism'. Presumably we don't explain mathematics or music or the desire to travel as either contracts or genetics, so we have other explanations available.
22. Metaethics / C. The Good / 2. Happiness / b. Eudaimonia
We need Eudaimonics - the empirical study of how we should flourish [Flanagan]
     Full Idea: It would be nice if I could advance the case for Eudaimonics - empirical enquiry into the nature, causes, and constituents of flourishing, …and the case for some ways of living and being as better than others.
     From: Owen Flanagan (The Really Hard Problem [2007], 4 'Normative')
     A reaction: Things seem to be moving in that direction. Lots of statistics about happiness have been appearing.
24. Political Theory / D. Ideologies / 9. Communism
Alienation is not finding what one wants, or being unable to achieve it [Flanagan]
     Full Idea: What Marx called 'alienation' is the widespread condition of not being able to discover what one wants, or not being remotely positioned to achieve.
     From: Owen Flanagan (The Really Hard Problem [2007], 2 'Expanding')
     A reaction: I took alienation to concern people's relationship to the means of production in their trade. On Flanagan's definition I would expect almost everyone aged under 20 to count as alienated.
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Given atomism at one end, and a finite universe at the other, there are no physical infinities [Brown,JR]
     Full Idea: There seem to be no actual infinites in the physical realm. Given the correctness of atomism, there are no infinitely small things, no infinite divisibility. And General Relativity says that the universe is only finitely large.
     From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5)
     A reaction: If time was infinite, you could travel round in a circle forever. An atom has size, so it has a left, middle and right to it. Etc. They seem to be physical, so we will count those too.
29. Religion / C. Spiritual Disciplines / 3. Buddhism
Buddhists reject God and the self, and accept suffering as key, and liberation through wisdom [Flanagan]
     Full Idea: Buddhism rejected the idea of a creator God, and the unchanging self [atman]. They accept the appearance-reality distinction, reward for virtue [karma], suffering defining our predicament, and that liberation [nirvana] is possible through wisdom.
     From: Owen Flanagan (The Really Hard Problem [2007], 3 'Buddhism')
     A reaction: [Compressed] Flanagan is an analytic philosopher and a practising Buddhist. Looking at a happiness map today which shows Europeans largely happy, and Africans largely miserable, I can see why they thought suffering was basic.