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All the ideas for 'Walking the Tightrope of Reason', 'Public Text and Common Reader' and 'Philosophies of Mathematics'

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68 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Philosophy may never find foundations, and may undermine our lives in the process [Fogelin]
     Full Idea: Not only is traditional philosophy incapable of discovering the foundations it seeks, but the philosophical enterprise may itself dislodge the contingent, de facto supports that our daily life depends upon.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2)
     A reaction: In the end Fogelin is not so pessimistic, but he is worried by the concern of philosophers with paradox and contradiction. I don't remotely consider this a reason to reject philosophy, but it might be a reason to keep it sealed off from daily life.
2. Reason / A. Nature of Reason / 1. On Reason
Rationality is threatened by fear of inconsistency, illusions of absolutes or relativism, and doubt [Fogelin]
     Full Idea: The three main threats to our rational lives are fear of inconsistency, illusions (of absolutism and relativism) and doubt.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4)
     A reaction: This is a very nice analysis of the forces that can destroy the philosopher's aspiration to the rational life. Personally I still suffer from a few illusions about the possibility of absolutes, but I may grow out of it. The other three don't bother me.
2. Reason / A. Nature of Reason / 9. Limits of Reason
Humans may never be able to attain a world view which is both rich and consistent [Fogelin]
     Full Idea: It might be wholly unreasonable to suppose that human beings will ever be able to attain a view of the world that is both suitably rich and completely consistent.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Intro)
     A reaction: Fogelin's lectures develop this view very persuasively. I think all philosophers must believe that the gods could attain a 'rich and consistent' view. Our problem is that we are a badly organised team, whose members keep dying.
A game can be played, despite having inconsistent rules [Fogelin]
     Full Idea: The presence of an inconsistency in the rules that govern a game need not destroy the game.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2)
     A reaction: He only defends this thesis if the inconsistency is away from the main centre of the action. You can't have an inconsistent definition of scoring a goal or a touchdown.
2. Reason / B. Laws of Thought / 1. Laws of Thought
The law of noncontradiction is traditionally the most basic principle of rationality [Fogelin]
     Full Idea: Traditionally many philosophers (Aristotle among them) have considered the law of noncontradiction to be the deepest, most fundamental principle of rationality.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.1)
     A reaction: For Aristotle, see Idea 1601 (and 'Metaphysics' 1005b28). The only denier of the basic character of the law that I know of is Nietzsche (Idea 4531). Fogelin, despite many qualifications, endorses the law, and so do I.
2. Reason / B. Laws of Thought / 3. Non-Contradiction
The law of noncontradiction makes the distinction between asserting something and denying it [Fogelin]
     Full Idea: People who reject the law of noncontradiction obliterate any significant difference between asserting something and denying it; …this will not move anyone who genuinely opts either for silence or for madness.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.1)
     A reaction: This seems a sufficiently firm and clear assertion of the basic nature of this law. The only rival view seems to be that of Nietzsche (Idea 4531), but then you wonder how Nietzsche is in a position to assert the relativity of the law.
2. Reason / D. Definition / 7. Contextual Definition
Contextual definitions replace a complete sentence containing the expression [George/Velleman]
     Full Idea: A contextual definition shows how to analyse an expression in situ, by replacing a complete sentence (of a particular form) in which the expression occurs by another in which it does not.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.2)
     A reaction: This is a controversial procedure, which (according to Dummett) Frege originally accepted, and later rejected. It might not be the perfect definition that replacing just the expression would give you, but it is a promising step.
2. Reason / D. Definition / 8. Impredicative Definition
Impredicative definitions quantify over the thing being defined [George/Velleman]
     Full Idea: When a definition contains a quantifier whose range includes the very entity being defined, the definition is said to be 'impredicative'.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.2)
     A reaction: Presumably they are 'impredicative' because they do not predicate a new quality in the definiens, but make use of the qualities already known.
2. Reason / E. Argument / 3. Analogy
Legal reasoning is analogical, not deductive [Fogelin]
     Full Idea: There is almost universal agreement that legal reasoning is fundamentally analogical, not deductive, in character.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2)
     A reaction: This raises the question of whether analogy can be considered as 'reasoning' in itself. How do you compare the examples? Could you compare two examples if you lacked language, or rules, or a scale of values?
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
The 'power set' of A is all the subsets of A [George/Velleman]
     Full Idea: The 'power set' of A is all the subsets of A. P(A) = {B : B ⊆ A}.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}} [George/Velleman]
     Full Idea: The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}}. The existence of this set is guaranteed by three applications of the Axiom of Pairing.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: See Idea 10100 for the Axiom of Pairing.
Cartesian Product A x B: the set of all ordered pairs in which a∈A and b∈B [George/Velleman]
     Full Idea: The 'Cartesian Product' of any two sets A and B is the set of all ordered pairs <a, b> in which a ∈ A and b ∈ B, and it is denoted as A x B.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
4. Formal Logic / F. Set Theory ST / 3. Types of Set / e. Equivalence classes
Grouping by property is common in mathematics, usually using equivalence [George/Velleman]
     Full Idea: The idea of grouping together objects that share some property is a common one in mathematics, ...and the technique most often involves the use of equivalence relations.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
'Equivalence' is a reflexive, symmetric and transitive relation; 'same first letter' partitions English words [George/Velleman]
     Full Idea: A relation is an equivalence relation if it is reflexive, symmetric and transitive. The 'same first letter' is an equivalence relation on the set of English words. Any relation that puts a partition into clusters will be equivalence - and vice versa.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: This is a key concept in the Fregean strategy for defining numbers.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Even the elements of sets in ZFC are sets, resting on the pure empty set [George/Velleman]
     Full Idea: ZFC is a theory concerned only with sets. Even the elements of all of the sets studied in ZFC are also sets (whose elements are also sets, and so on). This rests on one clearly pure set, the empty set Φ. ..Mathematics only needs pure sets.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: This makes ZFC a much more metaphysically comfortable way to think about sets, because it can be viewed entirely formally. It is rather hard to disentangle a chair from the singleton set of that chair.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
Axiom of Extensionality: for all sets x and y, if x and y have the same elements then x = y [George/Velleman]
     Full Idea: The Axiom of Extensionality says that for all sets x and y, if x and y have the same elements then x = y.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: This seems fine in pure set theory, but hits the problem of renates and cordates in the real world. The elements coincide, but the axiom can't tell you why they coincide.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / c. Axiom of Pairing II
Axiom of Pairing: for all sets x and y, there is a set z containing just x and y [George/Velleman]
     Full Idea: The Axiom of Pairing says that for all sets x and y, there is a set z containing x and y, and nothing else. In symbols: ∀x∀y∃z∀w(w ∈ z ↔ (w = x ∨ w = y)).
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: See Idea 10099 for an application of this axiom.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / p. Axiom of Reducibility
The Axiom of Reducibility made impredicative definitions possible [George/Velleman]
     Full Idea: The Axiom of Reducibility ...had the effect of making impredicative definitions possible.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
ZFC can prove that there is no set corresponding to the concept 'set' [George/Velleman]
     Full Idea: Sets, unlike extensions, fail to correspond to all concepts. We can prove in ZFC that there is no set corresponding to the concept 'set' - that is, there is no set of all sets.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4)
     A reaction: This is rather an important point for Frege. However, all concepts have extensions, but they may be proper classes, rather than precisely defined sets.
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
As a reduction of arithmetic, set theory is not fully general, and so not logical [George/Velleman]
     Full Idea: The problem with reducing arithmetic to ZFC is not that this theory is inconsistent (as far as we know it is not), but rather that is not completely general, and for this reason not logical. For example, it asserts the existence of sets.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4)
     A reaction: Note that ZFC has not been proved consistent.
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Asserting Excluded Middle is a hallmark of realism about the natural world [George/Velleman]
     Full Idea: A hallmark of our realist stance towards the natural world is that we are prepared to assert the Law of Excluded Middle for all statements about it. For all statements S, either S is true, or not-S is true.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4)
     A reaction: Personally I firmly subscribe to realism, so I suppose I must subscribe to Excluded Middle. ...Provided the statement is properly formulated. Or does liking excluded middle lead me to realism?
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'model' is a meaning-assignment which makes all the axioms true [George/Velleman]
     Full Idea: A 'model' of a theory is an assignment of meanings to the symbols of its language which makes all of its axioms come out true.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7)
     A reaction: If the axioms are all true, and the theory is sound, then all of the theorems will also come out true.
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
Differences between isomorphic structures seem unimportant [George/Velleman]
     Full Idea: Mathematicians tend to regard the differences between isomorphic mathematical structures as unimportant.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: This seems to be a pointer towards Structuralism as the underlying story in mathematics. The intrinsic character of so-called 'objects' seems unimportant. How theories map onto one another (and onto the world?) is all that matters?
5. Theory of Logic / K. Features of Logics / 2. Consistency
Consistency is a purely syntactic property, unlike the semantic property of soundness [George/Velleman]
     Full Idea: Consistency is a purely syntactic property, unlike the semantic property of soundness.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6)
A 'consistent' theory cannot contain both a sentence and its negation [George/Velleman]
     Full Idea: If there is a sentence such that both the sentence and its negation are theorems of a theory, then the theory is 'inconsistent'. Otherwise it is 'consistent'.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7)
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness is a semantic property, unlike the purely syntactic property of consistency [George/Velleman]
     Full Idea: Soundness is a semantic property, unlike the purely syntactic property of consistency.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6)
5. Theory of Logic / K. Features of Logics / 4. Completeness
A 'complete' theory contains either any sentence or its negation [George/Velleman]
     Full Idea: If there is a sentence such that neither the sentence nor its negation are theorems of a theory, then the theory is 'incomplete'. Otherwise it is 'complete'.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7)
     A reaction: Interesting questions are raised about undecidable sentences, irrelevant sentences, unknown sentences....
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
Rational numbers give answers to division problems with integers [George/Velleman]
     Full Idea: We can think of rational numbers as providing answers to division problems involving integers.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: Cf. Idea 10102.
The integers are answers to subtraction problems involving natural numbers [George/Velleman]
     Full Idea: In defining the integers in set theory, our definition will be motivated by thinking of the integers as answers to subtraction problems involving natural numbers.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: Typical of how all of the families of numbers came into existence; they are 'invented' so that we can have answers to problems, even if we can't interpret the answers. It it is money, we may say the minus-number is a 'debt', but is it? Cf Idea 10106.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers provide answers to square root problems [George/Velleman]
     Full Idea: One reason for introducing the real numbers is to provide answers to square root problems.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: Presumably the other main reasons is to deal with problems of exact measurement. It is interesting that there seem to be two quite distinct reasons for introducing the reals. Cf. Ideas 10102 and 10106.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / g. Applying mathematics
Logicists say mathematics is applicable because it is totally general [George/Velleman]
     Full Idea: The logicist idea is that if mathematics is logic, and logic is the most general of disciplines, one that applies to all rational thought regardless of its content, then it is not surprising that mathematics is widely applicable.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.2)
     A reaction: Frege was keen to emphasise this. You are left wondering why pure logic is applicable to the physical world. The only account I can give is big-time Platonism, or Pythagoreanism. Logic reveals the engine-room of nature, where the design is done.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
The classical mathematician believes the real numbers form an actual set [George/Velleman]
     Full Idea: Unlike the intuitionist, the classical mathematician believes in an actual set that contains all the real numbers.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Second-order induction is stronger as it covers all concepts, not just first-order definable ones [George/Velleman]
     Full Idea: The first-order version of the induction axiom is weaker than the second-order, because the latter applies to all concepts, but the first-order applies only to concepts definable by a formula in the first-order language of number theory.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7 n7)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
The Incompleteness proofs use arithmetic to talk about formal arithmetic [George/Velleman]
     Full Idea: The idea behind the proofs of the Incompleteness Theorems is to use the language of Peano Arithmetic to talk about the formal system of Peano Arithmetic itself.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7)
     A reaction: The mechanism used is to assign a Gödel Number to every possible formula, so that all reasonings become instances of arithmetic.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
A successor is the union of a set with its singleton [George/Velleman]
     Full Idea: For any set x, we define the 'successor' of x to be the set S(x) = x U {x}.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: This is the Fregean approach to successor, where the Dedekind approach takes 'successor' to be a primitive. Frege 1884:§76.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / d. Hume's Principle
Frege's Theorem shows the Peano Postulates can be derived from Hume's Principle [George/Velleman]
     Full Idea: The derivability of Peano's Postulates from Hume's Principle in second-order logic has been dubbed 'Frege's Theorem', (though Frege would not have been interested, because he didn't think Hume's Principle gave an adequate definition of numebrs).
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.8 n1)
     A reaction: Frege said the numbers were the sets which were the extensions of the sets created by Hume's Principle.
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set theory can prove the Peano Postulates [George/Velleman]
     Full Idea: The Peano Postulates can be proven in ZFC.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.7)
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
Talk of 'abstract entities' is more a label for the problem than a solution to it [George/Velleman]
     Full Idea: One might well wonder whether talk of abstract entities is less a solution to the empiricist's problem of how a priori knowledge is possible than it is a label for the problem.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Intro)
     A reaction: This pinpoints my view nicely. What the platonist postulates is remote, bewildering, implausible and useless!
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
If mathematics is not about particulars, observing particulars must be irrelevant [George/Velleman]
     Full Idea: As, in the logicist view, mathematics is about nothing particular, it is little wonder that nothing in particular needs to be observed in order to acquire mathematical knowledge.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002])
     A reaction: At the very least we can say that no one would have even dreamt of the general system of arithmetic is they hadn't had experience of the particulars. Frege thought generality ensured applicability, but extreme generality might entail irrelevance.
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
In the unramified theory of types, the types are objects, then sets of objects, sets of sets etc. [George/Velleman]
     Full Idea: In the unramified theory of types, all objects are classified into a hierarchy of types. The lowest level has individual objects that are not sets. Next come sets whose elements are individuals, then sets of sets, etc. Variables are confined to types.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: The objects are Type 0, the basic sets Type 1, etc.
The theory of types seems to rule out harmless sets as well as paradoxical ones. [George/Velleman]
     Full Idea: The theory of types seems to rule out harmless sets as well as paradoxical ones. If a is an individual and b is a set of individuals, then in type theory we cannot talk about the set {a,b}.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: Since we cheerfully talk about 'Cicero and other Romans', this sounds like a rather disasterous weakness.
Type theory has only finitely many items at each level, which is a problem for mathematics [George/Velleman]
     Full Idea: A problem with type theory is that there are only finitely many individuals, and finitely many sets of individuals, and so on. The hierarchy may be infinite, but each level is finite. Mathematics required an axiom asserting infinitely many individuals.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
     A reaction: Most accounts of mathematics founder when it comes to infinities. Perhaps we should just reject them?
Type theory prohibits (oddly) a set containing an individual and a set of individuals [George/Velleman]
     Full Idea: If a is an individual and b is a set of individuals, then in the theory of types we cannot talk about the set {a,b}, since it is not an individual or a set of individuals, ...but it is hard to see what harm can come from it.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.3)
6. Mathematics / C. Sources of Mathematics / 8. Finitism
Bounded quantification is originally finitary, as conjunctions and disjunctions [George/Velleman]
     Full Idea: In the first instance all bounded quantifications are finitary, for they can be viewed as abbreviations for conjunctions and disjunctions.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6)
     A reaction: This strikes me as quite good support for finitism. The origin of a concept gives a good guide to what it really means (not a popular view, I admit). When Aristotle started quantifying, I suspect of he thought of lists, not totalities.
Much infinite mathematics can still be justified finitely [George/Velleman]
     Full Idea: It is possible to use finitary reasoning to justify a significant part of infinitary mathematics.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.8)
     A reaction: This might save Hilbert's project, by gradually accepting into the fold all the parts which have been giving a finitist justification.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
The intuitionists are the idealists of mathematics [George/Velleman]
     Full Idea: The intuitionists are the idealists of mathematics.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.6)
Gödel's First Theorem suggests there are truths which are independent of proof [George/Velleman]
     Full Idea: For intuitionists, truth is not independent of proof, but this independence is precisely what seems to be suggested by Gödel's First Incompleteness Theorem.
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.8)
     A reaction: Thus Gödel was worse news for the Intuitionists than he was for Hilbert's Programme. Gödel himself responded by becoming a platonist about his unprovable truths.
10. Modality / C. Sources of Modality / 3. Necessity by Convention
Conventions can only work if they are based on something non-conventional [Fogelin]
     Full Idea: Convention, to exist at all, must have a basis in something that is not conventional; conventions, to work, need something nonconventional to build upon and shape.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3)
     A reaction: Fogelin attributes his point to Hume. I agree entirely. No convention could ever possibly catch on in a society unless there were some point to it. If you can't see a point to a convention (like wearing ties) then start looking, because it's there.
12. Knowledge Sources / C. Rationalism / 1. Rationalism
My view is 'circumspect rationalism' - that only our intellect can comprehend the world [Fogelin]
     Full Idea: My own view might be called 'circumspect rationalism' - the view that our intellectual faculties provide our only means for comprehending the world in which we find oruselves.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3)
     A reaction: He needs to say more than that to offer a theory, but I like the label, and it fits the modern revival of rationalism, with which I sympathise, and which rests, I think, on Russell's point that self-evidence comes in degrees, not as all-or-nothing truth.
13. Knowledge Criteria / A. Justification Problems / 1. Justification / c. Defeasibility
Knowledge is legitimate only if all relevant defeaters have been eliminated [Fogelin]
     Full Idea: In general a knowledge claim is legitimate only if all relevant defeaters have been eliminated.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4)
     A reaction: The problem here is what is 'relevant'. Fogelin's example is 'Are you sure the suspect doesn't have a twin brother?' If virtual reality is relevant, most knowledge is defeated. Certainly, imaginative people feel that they know less than others.
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / a. Coherence as justification
For coherentists, circularity is acceptable if the circle is large, rich and coherent [Fogelin]
     Full Idea: Coherentists argue that if the circle of justifications is big enough, rich enough, coherent enough, and so on, then there is nothing wrong circularity.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4)
     A reaction: There must always be something wrong with circularity, and no god would put up with it, but we might have to. Of course, two pieces of evidence might be unconnected, such as an equation and an observation.
13. Knowledge Criteria / C. External Justification / 6. Contextual Justification / a. Contextualism
A rule of justification might be: don't raise the level of scrutiny without a good reason [Fogelin]
     Full Idea: One rule for the justification of knowledge might be: Do not raise the level of scrutiny in the absence of a particular reason that triggers it.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4)
     A reaction: That won't decide the appropriate level of scrutiny from which to start. One of my maxims is 'don't set the bar too high', but it seems tough that one should have to justify moving it. The early scientists tried raising it, and were amazed by the results.
13. Knowledge Criteria / D. Scepticism / 2. Types of Scepticism
Scepticism is cartesian (sceptical scenarios), or Humean (future), or Pyrrhonian (suspend belief) [Fogelin]
     Full Idea: The three forms of scepticism are cartesian, Humean and Pyrrhonian. The first challenges belief by inventing sceptical scenarios; the second doubts the future; the third aims to suspend belief.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4)
     A reaction: A standard distinction is made between methodological and global scepticism. The former seems to be Cartesian, and the latter Pyrrhonian. The interest here is see Hume placed in a distinctive category, because of his views on induction.
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
Scepticism deals in remote possibilities that are ineliminable and set the standard very high [Fogelin]
     Full Idea: Sceptical scenarios deal in wildly remote defeating possibilities, so that the level of scrutiny becomes unrestrictedly high, and they also usually deal with defeators that are in principle ineliminable.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4)
     A reaction: The question of how high we 'set the bar' seems to me central to epistemology. There is clearly an element of social negotiation involved, centring on what is appropriate. If, though, scepticism is 'ineliminable', we must face up to that.
13. Knowledge Criteria / E. Relativism / 1. Relativism
Radical perspectivism replaces Kant's necessary scheme with many different schemes [Fogelin]
     Full Idea: We reach radical perspectivism by replacing Kant's single, necessary categorial scheme with a plurality of competing categorial schemes.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3)
     A reaction: It certainly looks as if Kant sent us down a slippery slope into the dafter aspects of twentieth century relativism. The best antidote I know of is Davidson's (e.g. Idea 6398). But then it seems unimaginative to say that only one scheme is possible.
18. Thought / A. Modes of Thought / 5. Rationality / b. Human rationality
We are also irrational, with a unique ability to believe in bizarre self-created fictions [Fogelin]
     Full Idea: We as human beings are also irrational animals, unique among animals in our capacity to place faith in bizarre fictions of our own construction.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Intro)
     A reaction: This is glaringly true, and a very nice corrective to the talk of Greeks and others about man as the 'rational animal'. From a distance we might be described by Martians as the 'mad animal'. Is the irrational current too strong to swim against?
18. Thought / D. Concepts / 1. Concepts / a. Nature of concepts
Corresponding to every concept there is a class (some of them sets) [George/Velleman]
     Full Idea: Corresponding to every concept there is a class (some classes will be sets, the others proper classes).
     From: A.George / D.J.Velleman (Philosophies of Mathematics [2002], Ch.4)
21. Aesthetics / A. Aesthetic Experience / 3. Taste
Literary meaning emerges in comparisons, and tradition shows which comparisons are relevant [Scruton]
     Full Idea: We must discover the meanings that emerge when works of literature are experience in relation to each other. ...The importance of tradition is that it denotes - ideally, at least - the class of relevant comparisons.
     From: Roger Scruton (Public Text and Common Reader [1982], p.27)
     A reaction: This is a nice attempt to explain why we all agree that a thorough education in an art is an essential prerequisite for good taste. Some people (e.g. among the young) seem to have natural good taste. How does that happen?
Critics must be causally entangled with their subject matter [Fogelin]
     Full Idea: Critics must become causally entangled with their subject matter.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.6)
     A reaction: This remark is built on Hume's views. You may have a strong view about a singer, but it may be hard to maintain when someone plays you six rival versions of the same piece. I agree entirely with the remark. It means there are aesthetic experts.
21. Aesthetics / A. Aesthetic Experience / 4. Beauty
The word 'beautiful', when deprived of context, is nearly contentless [Fogelin]
     Full Idea: Like the word 'good', the word 'beautiful', when deprived of contextual support, is nearly contentless.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.6)
     A reaction: If I say with, for example, Oscar Wilde that beauty is the highest ideal in life, this doesn't strike me as contentless, but I still sympathise with Fogelin's notion that beauty is rooted in particulars.
21. Aesthetics / B. Nature of Art / 5. Art as Language
In literature, word replacement changes literary meaning [Scruton]
     Full Idea: In literary contexts semantically equivalent words cannot replace each other without loss of literary meaning.
     From: Roger Scruton (Public Text and Common Reader [1982], p.25)
     A reaction: The notion of 'literary meaning' is not a standard one, and is questionable whether 'meaning' is the right word, given that a shift in word in a poem is as much to do with sound as with connotations.
21. Aesthetics / C. Artistic Issues / 1. Artistic Intentions
Without intentions we can't perceive sculpture, but that is not the whole story [Scruton]
     Full Idea: A person for whom it made no difference whether a sculpture was carved by wind and rain or by human hand would be unable to interpret or perceive sculptures - even though the interpretation of sculpture is not the reading of an intention.
     From: Roger Scruton (Public Text and Common Reader [1982], p.15)
     A reaction: Scruton compares it to the role of intention in language, where there is objective meaning, even though intention is basic to speech.
21. Aesthetics / C. Artistic Issues / 3. Artistic Representation
In aesthetic interest, even what is true is treated as though it were not [Scruton]
     Full Idea: In aesthetic interest, even what is true is treated as though it were not.
     From: Roger Scruton (Public Text and Common Reader [1982], p.18)
     A reaction: A nice aphorism. I always feel uncomfortable reading novels about real people, although the historical Macbeth doesn't bother me much. Novels are too close to reality. Macbeth didn't speak blank verse.
21. Aesthetics / C. Artistic Issues / 5. Objectivism in Art
We can be objective about conventions, but love of art is needed to understand its traditions [Scruton]
     Full Idea: An historian can elucidate convention while having no feeling for the art that exploits it; whereas an understanding of tradition is reserved for those with the critical insight which comes from the love of art, both past and present.
     From: Roger Scruton (Public Text and Common Reader [1982], p.24)
     A reaction: This aesthetic observation is obviously close to Scruton's well-known conservatism in politics. I am doubtful whether the notion of 'tradition' can stand up to close examination, though we all know roughly what he means.
Saying 'It's all a matter to taste' ignores the properties of the object discussed [Fogelin]
     Full Idea: "It is all a matter of taste" may be an all-purpose stopper of discussions of aesthetic values, but it also completely severs the connection with the actual properties of the object under consideration.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.6)
     A reaction: This remark grows out of his discussion of Hume. I like this remark, which ties in with Particularism in morality, and with the central role of experiments in science. The world forces beliefs on us.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Cynics are committed to morality, but disappointed or disgusted by human failings [Fogelin]
     Full Idea: Cynics are usually unswerving in their commitment to a moral ideal, but disappointed or disgusted by humanity's failure to meet it.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.3)
     A reaction: I felt quite suicidal the other day when I saw someone park diagonally across two parking spaces. They can't seem to grasp the elementary Kantian slogan 'What if everybody did that?' It's all hopeless. I wonder if I am becoming a bit of a Cynic?
25. Social Practice / D. Justice / 3. Punishment / a. Right to punish
Deterrence, prevention, rehabilitation and retribution can come into conflict in punishments [Fogelin]
     Full Idea: The purposes of punishment include deterrence, prevention, rehabilitation, and retribution, but they don't always sit well together. Deterrence is best served by making prisons miserable places, but this may run counter to rehabilitation.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2)
     A reaction: It seems to most educated people that retribution should be pushed far down the list if we are to be civilised (see Idea 1659), and yet personal revenge for a small act of aggression seems basic, normal and acceptable. We dream of rehabilitation.
Retributivists say a crime can be 'paid for'; deterrentists still worry about potential victims [Fogelin]
     Full Idea: A strict retributivist is likely to say that once a crime is paid for, that's that; a deterrence theorist is likely to say that the protection of potential victims overrides the released convict's right to a free and fresh start.
     From: Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.2)
     A reaction: Interesting since the retributivist here has the more liberal attitude. Reformists will also have a dilemma when years in prison have failed to reform the convict. Virtue theorists like balance, and sensitively consider our relations with the criminals.