80 ideas
| 8060 | In the 17th-18th centuries morality offered a cure for egoism, through altruism [MacIntyre] |
| Full Idea: It was in the seventeenth and eighteenth century that morality came generally to be understood as offering a solution to the problems posed by human egoism and that the content of morality came to be largely equated with altruism. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch.16) | |
| A reaction: It was the elevation of altruism that caused Nietzsche's rebellion. The sixteenth century certainly looks striking cynical to modern eyes. The development was an attempt to secularise Jesus. Altruism has a paradox: it needs victims. |
| 8053 | Twentieth century social life is re-enacting eighteenth century philosophy [MacIntyre] |
| Full Idea: Twentieth century social life turns out in key part to be the concrete and dramatic re-enactment of eighteenth-century philosophy. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 8) | |
| A reaction: This suggest a two hundred year lag between the philosophy and its impact on the culture. One might note the Victorian insistence on 'duty' (e.g. in George Eliot), alongside Mill's view that the Kantian account of it didn't work (Idea 3768). |
| 8047 | Philosophy has been marginalised by its failure in the Enlightenment to replace religion [MacIntyre] |
| Full Idea: The failure, in the Enlightenment, of philosophy to provide what religion could no longer furnish was an important cause of philosophy losing its central cultural role and becoming a marginal, narrowly academic subject. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 4) | |
| A reaction: A strange way of presenting the situation. Philosophy has never aspired to furnish beliefs for the masses. Plato offered them myths. The refutation of religion was difficult and complex. There is no returning from there to a new folk simplicity. |
| 8062 | Proof is a barren idea in philosophy, and the best philosophy never involves proof [MacIntyre] |
| Full Idea: Arguments in philosophy rarely take the form of proofs; and the most successful arguments on topics central to philosophy never do. (The ideal of proof is a relatively barren one in philosophy). | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch.18) | |
| A reaction: He seems proud of this, but he must settle for something which is less than proof, which has to be vindicated to the mathematicians and scientists. I agree, though. Plato is the model, and the best philosophy builds a broad persuasive picture. |
| 9355 | One sort of circularity presupposes a premise, the other presupposes a rule being used [Braithwaite, by Devitt] |
| Full Idea: An argument is 'premise-circular' if it aims to establish a conclusion that is assumed as a premise of that very argument. An argument is 'rule-circular' if it aims to establish a conclusion that asserts the goodness of the rule used in that argument. | |
| From: report of R.B. Braithwaite (Scientific Explanation [1953], p.274-8) by Michael Devitt - There is no a Priori §2 | |
| A reaction: Rule circularity is the sort of thing Quine is always objecting to, but such circularities may be unavoidable, and even totally benign. All the good things in life form a mutually supporting team. |
| 9535 | 'Contradictory' propositions always differ in truth-value [Lemmon] |
| Full Idea: Two propositions are 'contradictory' if they are never both true and never both false either, which means that ¬(A↔B) is a tautology. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9511 | We write the conditional 'if P (antecedent) then Q (consequent)' as P→Q [Lemmon] |
| Full Idea: We write 'if P then Q' as P→Q. This is called a 'conditional', with P as its 'antecedent', and Q as its 'consequent'. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.2) | |
| A reaction: P→Q can also be written as ¬P∨Q. |
| 9510 | That proposition that either P or Q is their 'disjunction', written P∨Q [Lemmon] |
| Full Idea: If P and Q are any two propositions, the proposition that either P or Q is called the 'disjunction' of P and Q, and is written P∨Q. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.3) | |
| A reaction: This is inclusive-or (meaning 'P, or Q, or both'), and not exlusive-or (Boolean XOR), which means 'P, or Q, but not both'. The ∨ sign is sometimes called 'vel' (Latin). |
| 9509 | That proposition that both P and Q is their 'conjunction', written P∧Q [Lemmon] |
| Full Idea: If P and Q are any two propositions, the proposition that both P and Q is called the 'conjunction' of P and Q, and is written P∧Q. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.3) | |
| A reaction: [I use the more fashionable inverted-v '∧', rather than Lemmon's '&', which no longer seems to be used] P∧Q can also be defined as ¬(¬P∨¬Q) |
| 9508 | The sign |- may be read as 'therefore' [Lemmon] |
| Full Idea: I introduce the sign |- to mean 'we may validly conclude'. To call it the 'assertion sign' is misleading. It may conveniently be read as 'therefore'. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.2) | |
| A reaction: [Actually no gap between the vertical and horizontal strokes of the sign] As well as meaning 'assertion', it may also mean 'it is a theorem that' (with no proof shown). |
| 9512 | We write the 'negation' of P (not-P) as ¬ [Lemmon] |
| Full Idea: We write 'not-P' as ¬P. This is called the 'negation' of P. The 'double negation' of P (not not-P) would be written as ¬¬P. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.2) | |
| A reaction: Lemmons use of -P is no longer in use for 'not'. A tilde sign (squiggle) is also used for 'not', but some interpreters give that a subtly different meaning (involving vagueness). The sign ¬ is sometimes called 'hook' or 'corner'. |
| 9513 | We write 'P if and only if Q' as P↔Q; it is also P iff Q, or (P→Q)∧(Q→P) [Lemmon] |
| Full Idea: We write 'P if and only if Q' as P↔Q. It is called the 'biconditional', often abbreviate in writing as 'iff'. It also says that P is both sufficient and necessary for Q, and may be written out in full as (P→Q)∧(Q→P). | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.4) | |
| A reaction: If this symbol is found in a sequence, the first move in a proof is to expand it to the full version. |
| 9514 | If A and B are 'interderivable' from one another we may write A -||- B [Lemmon] |
| Full Idea: If we say that A and B are 'interderivable' from one another (that is, A |- B and B |- A), then we may write A -||- B. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9516 | A 'well-formed formula' follows the rules for variables, ¬, →, ∧, ∨, and ↔ [Lemmon] |
| Full Idea: A 'well-formed formula' of the propositional calculus is a sequence of symbols which follows the rules for variables, ¬, →, ∧, ∨, and ↔. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.1) |
| 9517 | The 'scope' of a connective is the connective, the linked formulae, and the brackets [Lemmon] |
| Full Idea: The 'scope' of a connective in a certain formula is the formulae linked by the connective, together with the connective itself and the (theoretically) encircling brackets | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.1) |
| 9519 | A 'substitution-instance' is a wff formed by consistent replacing variables with wffs [Lemmon] |
| Full Idea: A 'substitution-instance' is a wff which results by replacing one or more variables throughout with the same wffs (the same wff replacing each variable). | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) |
| 9529 | A wff is 'inconsistent' if all assignments to variables result in the value F [Lemmon] |
| Full Idea: If a well-formed formula of propositional calculus takes the value F for all possible assignments of truth-values to its variables, it is said to be 'inconsistent'. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9531 | 'Contrary' propositions are never both true, so that ¬(A∧B) is a tautology [Lemmon] |
| Full Idea: If A and B are expressible in propositional calculus notation, they are 'contrary' if they are never both true, which may be tested by the truth-table for ¬(A∧B), which is a tautology if they are contrary. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9534 | Two propositions are 'equivalent' if they mirror one another's truth-value [Lemmon] |
| Full Idea: Two propositions are 'equivalent' if whenever A is true B is true, and whenever B is true A is true, in which case A↔B is a tautology. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9530 | A wff is 'contingent' if produces at least one T and at least one F [Lemmon] |
| Full Idea: If a well-formed formula of propositional calculus takes at least one T and at least one F for all the assignments of truth-values to its variables, it is said to be 'contingent'. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9532 | 'Subcontrary' propositions are never both false, so that A∨B is a tautology [Lemmon] |
| Full Idea: If A and B are expressible in propositional calculus notation, they are 'subcontrary' if they are never both false, which may be tested by the truth-table for A∨B, which is a tautology if they are subcontrary. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9533 | A 'implies' B if B is true whenever A is true (so that A→B is tautologous) [Lemmon] |
| Full Idea: One proposition A 'implies' a proposition B if whenever A is true B is true (but not necessarily conversely), which is only the case if A→B is tautologous. Hence B 'is implied' by A. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9528 | A wff is a 'tautology' if all assignments to variables result in the value T [Lemmon] |
| Full Idea: If a well-formed formula of propositional calculus takes the value T for all possible assignments of truth-values to its variables, it is said to be a 'tautology'. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.3) |
| 9518 | A 'theorem' is the conclusion of a provable sequent with zero assumptions [Lemmon] |
| Full Idea: A 'theorem' of logic is the conclusion of a provable sequent in which the number of assumptions is zero. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) | |
| A reaction: This is what Quine and others call a 'logical truth'. |
| 9398 | ∧I: Given A and B, we may derive A∧B [Lemmon] |
| Full Idea: And-Introduction (&I): Given A and B, we may derive A∧B as conclusion. This depends on their previous assumptions. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9397 | CP: Given a proof of B from A as assumption, we may derive A→B [Lemmon] |
| Full Idea: Conditional Proof (CP): Given a proof of B from A as assumption, we may derive A→B as conclusion, on the remaining assumptions (if any). | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9394 | MPP: Given A and A→B, we may derive B [Lemmon] |
| Full Idea: Modus Ponendo Ponens (MPP): Given A and A→B, we may derive B as a conclusion. B will rest on any assumptions that have been made. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9401 | ∨E: Derive C from A∨B, if C can be derived both from A and from B [Lemmon] |
| Full Idea: Or-Elimination (∨E): Given A∨B, we may derive C if it is proved from A as assumption and from B as assumption. This will also depend on prior assumptions. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9396 | DN: Given A, we may derive ¬¬A [Lemmon] |
| Full Idea: Double Negation (DN): Given A, we may derive ¬¬A as a conclusion, and vice versa. The conclusion depends on the assumptions of the premiss. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9393 | A: we may assume any proposition at any stage [Lemmon] |
| Full Idea: Assumptions (A): any proposition may be introduced at any stage of a proof. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9399 | ∧E: Given A∧B, we may derive either A or B separately [Lemmon] |
| Full Idea: And-Elimination (∧E): Given A∧B, we may derive either A or B separately. The conclusions will depend on the assumptions of the premiss. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9402 | RAA: If assuming A will prove B∧¬B, then derive ¬A [Lemmon] |
| Full Idea: Reduction ad Absurdum (RAA): Given a proof of B∧¬B from A as assumption, we may derive ¬A as conclusion, depending on the remaining assumptions (if any). | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9395 | MTT: Given ¬B and A→B, we derive ¬A [Lemmon] |
| Full Idea: Modus Tollendo Tollens (MTT): Given ¬B and A→B, we derive ¬A as a conclusion. ¬A depends on any assumptions that have been made | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9400 | ∨I: Given either A or B separately, we may derive A∨B [Lemmon] |
| Full Idea: Or-Introduction (∨I): Given either A or B separately, we may derive A∨B as conclusion. This depends on the assumption of the premisses. | |
| From: E.J. Lemmon (Beginning Logic [1965], 1.5) |
| 9521 | 'Modus tollendo ponens' (MTP) says ¬P, P ∨ Q |- Q [Lemmon] |
| Full Idea: 'Modus tollendo ponens' (MTP) says that if a disjunction holds and also the negation of one of its disjuncts, then the other disjunct holds. Thus ¬P, P ∨ Q |- Q may be introduced as a theorem. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) | |
| A reaction: Unlike Modus Ponens and Modus Tollens, this is a derived rule. |
| 9522 | 'Modus ponendo tollens' (MPT) says P, ¬(P ∧ Q) |- ¬Q [Lemmon] |
| Full Idea: 'Modus ponendo tollens' (MPT) says that if the negation of a conjunction holds and also one of its conjuncts, then the negation of the other conjunct holds. Thus P, ¬(P ∧ Q) |- ¬Q may be introduced as a theorem. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) | |
| A reaction: Unlike Modus Ponens and Modus Tollens, this is a derived rule. |
| 9525 | We can change conditionals into negated conjunctions with P→Q -||- ¬(P ∧ ¬Q) [Lemmon] |
| Full Idea: The proof that P→Q -||- ¬(P ∧ ¬Q) is useful for enabling us to change conditionals into negated conjunctions | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) |
| 9524 | We can change conditionals into disjunctions with P→Q -||- ¬P ∨ Q [Lemmon] |
| Full Idea: The proof that P→Q -||- ¬P ∨ Q is useful for enabling us to change conditionals into disjunctions. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) |
| 9523 | De Morgan's Laws make negated conjunctions/disjunctions into non-negated disjunctions/conjunctions [Lemmon] |
| Full Idea: The forms of De Morgan's Laws [P∨Q -||- ¬(¬P ∧ ¬Q); ¬(P∨Q) -||- ¬P ∧ ¬Q; ¬(P∧Q) -||- ¬P ∨ ¬Q); P∧Q -||- ¬(¬P∨¬Q)] transform negated conjunctions and disjunctions into non-negated disjunctions and conjunctions respectively. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) |
| 9527 | The Distributive Laws can rearrange a pair of conjunctions or disjunctions [Lemmon] |
| Full Idea: The Distributive Laws say that P ∧ (Q∨R) -||- (P∧Q) ∨ (P∧R), and that P ∨ (Q∨R) -||- (P∨Q) ∧ (P∨R) | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) |
| 9526 | We can change conjunctions into negated conditionals with P→Q -||- ¬(P → ¬Q) [Lemmon] |
| Full Idea: The proof that P∧Q -||- ¬(P → ¬Q) is useful for enabling us to change conjunctions into negated conditionals. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) |
| 9537 | Truth-tables are good for showing invalidity [Lemmon] |
| Full Idea: The truth-table approach enables us to show the invalidity of argument-patterns, as well as their validity. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.4) |
| 9538 | A truth-table test is entirely mechanical, but this won't work for more complex logic [Lemmon] |
| Full Idea: A truth-table test is entirely mechanical, ..and in propositional logic we can even generate proofs mechanically for tautological sequences, ..but this mechanical approach breaks down with predicate calculus, and proof-discovery is an imaginative process. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.5) |
| 9536 | If any of the nine rules of propositional logic are applied to tautologies, the result is a tautology [Lemmon] |
| Full Idea: If any application of the nine derivation rules of propositional logic is made on tautologous sequents, we have demonstrated that the result is always a tautologous sequent. Thus the system is consistent. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.4) | |
| A reaction: The term 'sound' tends to be used now, rather than 'consistent'. See Lemmon for the proofs of each of the nine rules. |
| 9539 | Propositional logic is complete, since all of its tautologous sequents are derivable [Lemmon] |
| Full Idea: A logical system is complete is all expressions of a specified kind are derivable in it. If we specify tautologous sequent-expressions, then propositional logic is complete, because we can show that all tautologous sequents are derivable. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.5) | |
| A reaction: [See Lemmon 2.5 for details of the proofs] |
| 13909 | Write '(∀x)(...)' to mean 'take any x: then...', and '(∃x)(...)' to mean 'there is an x such that....' [Lemmon] |
| Full Idea: Just as '(∀x)(...)' is to mean 'take any x: then....', so we write '(∃x)(...)' to mean 'there is an x such that....' | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.1) | |
| A reaction: [Actually Lemmon gives the universal quantifier symbol as '(x)', but the inverted A ('∀') seems to have replaced it these days] |
| 13902 | 'Gm' says m has property G, and 'Pmn' says m has relation P to n [Lemmon] |
| Full Idea: A predicate letter followed by one name expresses a property ('Gm'), and a predicate-letter followed by two names expresses a relation ('Pmn'). We could write 'Pmno' for a complex relation like betweenness. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.1) |
| 13911 | The 'symbols' are bracket, connective, term, variable, predicate letter, reverse-E [Lemmon] |
| Full Idea: I define a 'symbol' (of the predicate calculus) as either a bracket or a logical connective or a term or an individual variable or a predicate-letter or reverse-E (∃). | |
| From: E.J. Lemmon (Beginning Logic [1965], 4.1) |
| 13910 | Our notation uses 'predicate-letters' (for 'properties'), 'variables', 'proper names', 'connectives' and 'quantifiers' [Lemmon] |
| Full Idea: Quantifier-notation might be thus: first, render into sentences about 'properties', and use 'predicate-letters' for them; second, introduce 'variables'; third, introduce propositional logic 'connectives' and 'quantifiers'. Plus letters for 'proper names'. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.1) |
| 13904 | Universal Elimination (UE) lets us infer that an object has F, from all things having F [Lemmon] |
| Full Idea: Our rule of universal quantifier elimination (UE) lets us infer that any particular object has F from the premiss that all things have F. It is a natural extension of &E (and-elimination), as universal propositions generally affirm a complex conjunction. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.2) |
| 13906 | With finite named objects, we can generalise with &-Intro, but otherwise we need ∀-Intro [Lemmon] |
| Full Idea: If there are just three objects and each has F, then by an extension of &I we are sure everything has F. This is of no avail, however, if our universe is infinitely large or if not all objects have names. We need a new device, Universal Introduction, UI. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.2) |
| 13908 | UE all-to-one; UI one-to-all; EI arbitrary-to-one; EE proof-to-one [Lemmon] |
| Full Idea: Univ Elim UE - if everything is F, then something is F; Univ Intro UI - if an arbitrary thing is F, everything is F; Exist Intro EI - if an arbitrary thing is F, something is F; Exist Elim EE - if a proof needed an object, there is one. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.3) | |
| A reaction: [My summary of Lemmon's four main rules for predicate calculus] This is the natural deduction approach, of trying to present the logic entirely in terms of introduction and elimination rules. See Bostock on that. |
| 13901 | Predicate logic uses propositional connectives and variables, plus new introduction and elimination rules [Lemmon] |
| Full Idea: In predicate calculus we take over the propositional connectives and propositional variables - but we need additional rules for handling quantifiers: four rules, an introduction and elimination rule for the universal and existential quantifiers. | |
| From: E.J. Lemmon (Beginning Logic [1965]) | |
| A reaction: This is Lemmon's natural deduction approach (invented by Gentzen), which is largely built on introduction and elimination rules. |
| 13903 | Universal elimination if you start with the universal, introduction if you want to end with it [Lemmon] |
| Full Idea: The elimination rule for the universal quantifier concerns the use of a universal proposition as a premiss to establish some conclusion, whilst the introduction rule concerns what is required by way of a premiss for a universal proposition as conclusion. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.2) | |
| A reaction: So if you start with the universal, you need to eliminate it, and if you start without it you need to introduce it. |
| 13905 | If there is a finite domain and all objects have names, complex conjunctions can replace universal quantifiers [Lemmon] |
| Full Idea: If all objects in a given universe had names which we knew and there were only finitely many of them, then we could always replace a universal proposition about that universe by a complex conjunction. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.2) |
| 13900 | 'Some Frenchmen are generous' is rendered by (∃x)(Fx→Gx), and not with the conditional → [Lemmon] |
| Full Idea: It is a common mistake to render 'some Frenchmen are generous' by (∃x)(Fx→Gx) rather than the correct (∃x)(Fx&Gx). 'All Frenchmen are generous' is properly rendered by a conditional, and true if there are no Frenchmen. | |
| From: E.J. Lemmon (Beginning Logic [1965], 3.1) | |
| A reaction: The existential quantifier implies the existence of an x, but the universal quantifier does not. |
| 9520 | The paradoxes of material implication are P |- Q → P, and ¬P |- P → Q [Lemmon] |
| Full Idea: The paradoxes of material implication are P |- Q → P, and ¬P |- P → Q. That is, since Napoleon was French, then if the moon is blue then Napoleon was French; and since Napoleon was not Chinese, then if Napoleon was Chinese, the moon is blue. | |
| From: E.J. Lemmon (Beginning Logic [1965], 2.2) | |
| A reaction: This is why the symbol → does not really mean the 'if...then' of ordinary English. Russell named it 'material implication' to show that it was a distinctively logical operator. |
| 8052 | To find empiricism and science in the same culture is surprising, as they are really incompatible [MacIntyre] |
| Full Idea: There is something extraordinary in the coexistence of empiricism and natural science in the same culture, for they represent radically different and incompatible ways of approaching the world. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 7) | |
| A reaction: I would say that science is commitment to an ontology, and empiricism is a commitment to epistemology. It is a very nice point, given the usual assumption that science is an empirical activity. See Idea 7621. Strict empiricism distorts science. |
| 8057 | Unpredictability doesn't entail inexplicability, and predictability doesn't entail explicability [MacIntyre] |
| Full Idea: Just as unpredictability does not entail inexplicability, so predictability does not entail explicability. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 8) | |
| A reaction: The second half is not quite as obvious as the first. The location of lightning strikes is an example of the first. He gives examples of the second, but they all seem to be very complex cases which might be explained, if only we knew enough. |
| 8054 | Social sciences discover no law-like generalisations, and tend to ignore counterexamples [MacIntyre] |
| Full Idea: Social sciences have discovered no law-like generalisations whatsoever, ...and for the most part they adopt a very tolerant attitude to counter-examples. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 8) | |
| A reaction: I suspect that this is as much to do with a narrow and rigid view of what 'science' is supposed to be, as a failure of the social sciences. Have such sciences explained anything? I suspect that they have explained a lot, often after the facts. |
| 21050 | I can only make decisions if I see myself as part of a story [MacIntyre] |
| Full Idea: I can only answer the question 'What am I to do?' if I can answer the prior question 'Of what story or stories do I find myself a part?'. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], p.201), quoted by Michael J. Sandel - Justice: What's the right thing to do? 09 | |
| A reaction: MacIntyre is a great champion of the narrative view of the Self. Does this mean that if you had total amnesia, but retained other faculties, you could make no decisions? Can you start a new story whenever you like? |
| 8056 | AI can't predict innovation, or consequences, or external relations, or external events [MacIntyre] |
| Full Idea: AI machines have four types of unpredictability: they can't predict radical innovation or future maths proofs; they couldn't predict the outcome of their own decisions; their relations with other computers would be a game-theory tangle; and power failure. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 8) | |
| A reaction: This isn't an assertion that they lack 'free will', just a very accurate observation of how the super new machines would face exactly the same problems that we ourselves face. |
| 8059 | The good life for man is the life spent seeking the good life for man [MacIntyre] |
| Full Idea: The good life for man is the life spent in seeking for the good life for man. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch.15) | |
| A reaction: This contains a self-evident paradox - that success would be failure. The proposal suits philosophers more than it would suit the folk. Less seeking and more getting on with it seems good, if the activity is a 'flourishing' one. |
| 8034 | We still have the appearance and language of morality, but we no longer understand it [MacIntyre] |
| Full Idea: We possess simulacra of morality, we continue to use many of the key expressions. But we have - very largely, if not entirely - lost our comprehension, both theoretical and practical, of morality. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 1) | |
| A reaction: MacIntyre's famous (or notorious) assault on modern ethics. We obviously can't prove him wrong by spouting moral talk. Are we actually more wicked than our ancestors? There is, I think, a relativism problem in the 20th centurty, but that is different. |
| 8036 | Unlike expressions of personal preference, evaluative expressions do not depend on context [MacIntyre] |
| Full Idea: There are good reasons for distinguishing between expressions of personal preference and evaluative expressions, as the first depend on who utters them to whom, while the second are not dependent for reason-giving force on the context of utterance. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 2) | |
| A reaction: The sceptics will simply say that in the second type of expression the speaker tries to adopt a tone of impersonal authority, but it is merely an unjustified attempt to elevate personal preferences. "Blue just IS the best colour". |
| 8049 | Moral judgements now are anachronisms from a theistic age [MacIntyre] |
| Full Idea: Moral judgements are linguistic survivals from the practices of classical theism which have lost the context provided by these practices. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 5) | |
| A reaction: He is sort of right. Richard Taylor is less dramatic and more plausible on this (Ideas 5065, 5066, 5077). Big claims about 'duty' have become rather hollow, but the rights and wrongs of (e.g.) mistreating children don't seem to need theism. |
| 8045 | The failure of Enlightenment attempts to justify morality will explain our own culture [MacIntyre] |
| Full Idea: A central thesis of this book is that the breakdown of the project (of 1630 to 1850) of an independent rational justification of morality provided the historical background against which the predicaments of our own culture can become intelligible. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 4) | |
| A reaction: Possibly the most important question of our times is whether the Enlightenment failed. MacIntyre's claim is followed by an appeal for a return to Aristotelian/Thomist virtues. Continentals seem to have responded by sliding into relativism. |
| 8051 | Mention of 'intuition' in morality means something has gone wrong with the argument [MacIntyre] |
| Full Idea: The introduction of the word 'intuition' by a moral philosopher is always a signal that something has gone badly wrong with an argument. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 6) | |
| A reaction: For the alternative view, see Kripke (Idea 4948). If Kripke is right about logic, I don't see why the same view should have some force in morality. At the bottom of all morality is an intuition that life is worth the struggle. How do you prove that? |
| 8048 | When 'man' is thought of individually, apart from all roles, it ceases to be a functional concept [MacIntyre] |
| Full Idea: It is only when man is thought of as an individual prior to and apart from all roles that 'man' ceases to be a functional concept. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 5) | |
| A reaction: This is the one key idea at the heart of the revival of virtue ethics in modern times. It pinpoints what may be the single biggest disaster in intellectual history - the isolation of the individual. Yet it led to freedom, rights, and lots of good things. |
| 8035 | In trying to explain the type of approval involved, emotivists are either silent, or viciously circular [MacIntyre] |
| Full Idea: In reply to the question of what kinds of approval are expressed by the feelings or attitudes of moral judgments, every version of emotivism either remains silent, or becomes viciously circular by identifying it as moral approval. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 2) | |
| A reaction: There seems to be an underlying assumption that moral judgements are sharply separated from other judgements, of which I am not convinced. I approve of creating a beautiful mural for an old folks home free of charge, but it must be beautiful. |
| 8037 | The expression of feeling in a sentence is in its use, not in its meaning [MacIntyre] |
| Full Idea: Expression of feeling is not a function of the meaning of sentences, but of their use, as when a teacher shouts at a pupil "7 x 7 = 49!", where the expression of feeling or attitude has nothing whatsoever to do with its meaning. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 2) | |
| A reaction: This point is what underlies the Frege-Geach problem for emotivism, and is a very telling point. Apart from in metaethics, no one has ever put forward a theory of meaning that says it is just emotion. ...Unless it concerns speakers' intentions? |
| 8040 | Emotivism cannot explain the logical terms in moral discourse ('therefore', 'if..then') [MacIntyre] |
| Full Idea: Analytical moral philosophers resist emotivism because moral reasoning does occur, but there can be logical linkages between various moral judgements of a kind that emotivism could not allow for ('therefore' and 'if...then' express no moral feelings). | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 2) | |
| A reaction: This is the 'Frege-Geach Problem', nicely expressed, and is the key reason why emotivism seems unacceptable - it is a theory about language, but it just doesn't explain moral discourse sufficiently. |
| 8042 | Nowadays most people are emotivists, and it is embodied in our culture [MacIntyre] |
| Full Idea: To a large degree people now think, talk and act as if emotivism was true, no matter what their avowed theoretical standpoint may be. Emotivism has become embodied in our culture. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 2) | |
| A reaction: I suspect that it is moderately educated people who have swallowed emotivism, in the same way that they have swallowed relativism; it provides an excuse for neglectly the pursuit of beauty, goodness and truth, in favour of pleasure. |
| 8058 | Maybe we can only understand rules if we first understand the virtues [MacIntyre] |
| Full Idea: Maybe we need to attend to the virtues first in the first place in order to understand the function and authority of rules. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 9) | |
| A reaction: I think MacIntyre's project is exactly right. Morality is about how humans should live their lives. A bunch of robots could implement a set of moral rules, or make contracts, or maximise one another's benefits. The idea of a human community comes first. |
| 7097 | Virtue is secondary to a role-figure, defined within a culture [MacIntyre, by Statman] |
| Full Idea: MacIntyre argues that the concept of virtue is secondary to that of a role-figure, where the latter is always defined by some particular tradition and culture. | |
| From: report of Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981]) by Daniel Statman - Introduction to Virtue Ethics §3 | |
| A reaction: MacIntyre is much more of a relativist than Aristotle. There must be some attempt to deal with the problem of a rotten culture which throws up a corrupt role-model. We need a concept of a good culture and of individual flourishing. |
| 8043 | Characters are the masks worn by moral philosophies [MacIntyre] |
| Full Idea: Characters are the masks worn by moral philosophies. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 3) | |
| A reaction: This may be presenting character in an excessively moral way. Being lively, for example, is a very distinctive trait of character, but hardly moral. This tells us why philosophers are interested in character, but not why other people are. |
| 8061 | If morality just is emotion, there are no external criteria for judging emotions [MacIntyre] |
| Full Idea: If there is nothing to judgements of virtue and vice except the expression of feelings of approval and disapproval, there can be no criteria external to those feelings by appeal to which we may pass judgement upon them. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch.16) | |
| A reaction: The idea that there can be right and wrong feelings may be the key idea in virtue theory. See Idea 5217. A good person would be ashamed to have a bad feeling. Some emotional responses are intrinsically wicked, apart from actions. |
| 8038 | Since Moore thinks the right action produces the most good, he is a utilitarian [MacIntyre] |
| Full Idea: Moore takes it that to call an action right is simply to say that of the available alternative actions it is the one which does or did as a matter of fact produce the most good. Moore is thus a utilitarian. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 2) | |
| A reaction: Far be it from me to disagree with MacIntyre on this, but I would have thought that this made him a consequentialist, rather than a utilitarian. Moore doesn't remotely think that pure pleasure or happiness is the good. He's closer to Rashdall (Idea 6673). |
| 8050 | There are no natural or human rights, and belief in them is nonsense [MacIntyre] |
| Full Idea: There are no natural or human rights, and belief in them is one with belief in witches and in unicorns. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 6) | |
| A reaction: His point is that the notion of 'rights' only arises out of a community. However, while you might criticise an individual for absurdly asserting all sorts of dubious rights, no one could criticise them if they asserted the right to defend their own life. |
| 8055 | If God is omniscient, he confronts no as yet unmade decisions, so decisions are impossible [MacIntyre] |
| Full Idea: Omniscience excludes the making of decisions. If God knows everything that will occur, he confronts no as yet unmade decisions. | |
| From: Alasdair MacIntyre (After Virtue: a Study in Moral Theory [1981], Ch. 8) | |
| A reaction: [He cites Aquinas on this] I find it very difficult to see how anyone could read the Bible (see Idea 8008) while keeping this point continually in mind, without seeing the whole book as a piece of blatant anthropomorphism. |