48 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. |
| 17749 | 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) |
| 17765 | 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). |
| 17764 | 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. |
| 17752 | 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) |
| 17753 | 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. |
| 17759 | 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. |
| 17741 | 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. |
| 17747 | 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. |
| 17748 | 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????? |
| 17761 | 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) |
| 17763 | 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) |
| 17758 | 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) |
| 17755 | 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. |
| 17756 | 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) |
| 17760 | 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. |
| 17757 | 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) |
| 17762 | 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) |
| 17754 | 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. |
| 17742 | 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) |
| 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. |
| 7861 | Libet says the processes initiated in the cortex can still be consciously changed [Libet, by Papineau] |
| Full Idea: Libet himself points out that the conscious decisions still have the power to 'endorse' or 'cancel', so to speak, the processes initiated by the earlier cortical activity: no action will result if the action's execution is consciously countermanded. | |
| From: report of Benjamin Libet (Unconscious Cerebral Initiative [1985]) by David Papineau - Thinking about Consciousness 1.4 | |
| A reaction: This is why Libet's findings do not imply 'epiphenomenalism'. It seems that part of a decisive action is non-conscious, undermining the all-or-nothing view of consciousness. Searle tries to smuggle in free will at this point (Idea 3817). |
| 6660 | Libet found conscious choice 0.2 secs before movement, well after unconscious 'readiness potential' [Libet, by Lowe] |
| Full Idea: Libet found that a subject's conscious choice to move was about a fifth of a second before movement, and thus later than the onset of the brain's so-called 'readiness potential', which seems to imply that unconscious processes initiates action. | |
| From: report of Benjamin Libet (Unconscious Cerebral Initiative [1985]) by E.J. Lowe - Introduction to the Philosophy of Mind Ch.9 | |
| A reaction: Of great interest to philosophers! It seems to make conscious choices epiphenomenal. The key move, I think, is to give up the idea of consciousness as being all-or-nothing. My actions are still initiated by 'me', but 'me' shades off into unconsciousness. |
| 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. |