36 ideas
| 22271 | Aristotle was the first to use schematic letters in logic [Aristotle, by Potter] |
| Full Idea: It was Aristotle who initiated the use of the letter of the (Greek) alphabet 'schematically', to stand for an unspecified piece of language of some appropriate grammatical type. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 02 'Aris' | |
| A reaction: Did he invent it from scratch, or borrow it from the mathematicians? Euclid labels diagrams with letters. |
| 11060 | Aristotelian syllogisms are three-part, subject-predicate, existentially committed, with laws of thought [Aristotle, by Hanna] |
| Full Idea: Aristotle's logic is based on the triadic syllogism, the distinction between subject and one-place predicates, that universal claims have existential commitment, and bivalence, excluded middle and noncontradiction. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by Robert Hanna - Rationality and Logic 2.2 |
| 18909 | Aristotelian sentences are made up by one of four 'formative' connectors [Aristotle, by Engelbretsen] |
| Full Idea: For Aristotle there are four formatives for sentences: 'belongs to some', 'belongs to every', 'belongs to no', and 'does not belong to every'. These are 'copulae'. Aristotle would have written 'wise belongs to some man'. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by George Engelbretsen - Trees, Terms and Truth 3 | |
| A reaction: A rather set-theoretic reading. This invites a Quinean scepticism about whether wisdom is some entity which can 'belong' to a person. It makes trope theory sound attractive, offering a unique wisdom that is integrated into that particular person. |
| 8080 | Aristotelian identified 256 possible syllogisms, saying that 19 are valid [Aristotle, by Devlin] |
| Full Idea: Aristotle identified four 'figures' of argument, based on combinations of Subject (S) and Predicate (P) and Middle term (M). The addition of 'all' and 'some', and 'has' and 'has not' got the property, resulted in 256 possible syllogisms, 19 of them valid. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by Keith Devlin - Goodbye Descartes Ch.2 | |
| A reaction: [Compressed version of Devlin] What Aristotle did was astonishing, and must be one of the key ideas of western civilization, even though a lot of his assumptions have been revised or rejected. |
| 13912 | Aristotle replaced Plato's noun-verb form with unions of pairs of terms by one of four 'copulae' [Aristotle, by Engelbretsen/Sayward] |
| Full Idea: Aristotle replaced the Platonic noun-verb account of logical syntax with a 'copular' account. A sentence is a pair of terms bound together logically (not necessarily grammatically) by one of four 'logical copulae' (every, none, some, not some). | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by Engelbretsen,G/Sayward,C - Philosophical Logic: Intro to Advanced Topics 8 | |
| A reaction: So the four copulas are are-all, are-never, are-sometimes, and are-sometime-not. Consider 'men' and 'mortal'. Alternatively, Idea 18909. |
| 8071 | Aristotle listed nineteen valid syllogisms (though a few of them were wrong) [Aristotle, by Devlin] |
| Full Idea: Aristotle listed a total of nineteen syllogisms involved in logical reasoning, though some of the ones on his list were subsequently shown to be invalid. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE], Ch.1) by Keith Devlin - Goodbye Descartes | |
| A reaction: It is quite upsetting to think that the founding genius got some of it wrong, but that just shows how subtle and complex the analysis of rational thought can be. |
| 13819 | Aristotle's said some Fs are G or some Fs are not G, forgetting that there might be no Fs [Bostock on Aristotle] |
| Full Idea: Aristotle's system accepted as correct some laws which nowadays we reject, for example |= (Some Fs are G) or (some Fs are not G). He failed to take into account the possibility of there being no Fs at all. | |
| From: comment on Aristotle (Prior Analytics [c.328 BCE]) by David Bostock - Intermediate Logic 8.4 |
| 9403 | There are three different deductions for actual terms, necessary terms and possible terms [Aristotle] |
| Full Idea: Since to belong, to belong of necessity, and to be possible to belong are different, ..there will be different deductions for each; one deduction will be from necessary terms, one from terms which belong, and one from possible terms. | |
| From: Aristotle (Prior Analytics [c.328 BCE], 29b29-35) | |
| A reaction: Fitting and Mendelsohn cite this as the earliest thoughts on modal logic. but Kneale and Kneale say that Aristotle got into a muddle, and so was unable to create a workable system. |
| 11148 | Deduction is when we suppose one thing, and another necessarily follows [Aristotle] |
| Full Idea: A deduction is a discourse in which, certain things having been supposed, something different from the things supposed results of necessity because these things are so. | |
| From: Aristotle (Prior Analytics [c.328 BCE], 24b18) | |
| A reaction: Notice that it is modal ('suppose', rather than 'know'), that necessity is involved, which is presumably metaphysical necessity, and that there are assumptions about what would be true, and not just what follows from what. |
| 18896 | Aristotle places terms at opposite ends, joined by a quantified copula [Aristotle, by Sommers] |
| Full Idea: Aristotle often preferred to formulate predications by placing the terms at opposite ends of the sentence and joining them by predicating expressions like 'belongs-to-some' or 'belongs-to-every'. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by Fred Sommers - Intellectual Autobiography 'Conceptions' | |
| A reaction: This is Sommers's picture of Aristotle, which led Sommers to develop his modern Term Logic. |
| 3300 | Aristotle's logic is based on the subject/predicate distinction, which leads him to substances and properties [Aristotle, by Benardete,JA] |
| Full Idea: Basic to Aristotle's logic is the grammatical distinction between subject and predicate, which he glosses in terms of the contrast between a substance and its properties. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by José A. Benardete - Metaphysics: the logical approach Intro | |
| A reaction: The introduction of quantifiers and 'logical form' can't disguise the fact that we still talk about (and with) objects and predicates, because no one can think of any other way to talk. |
| 11149 | Affirming/denying sentences are universal, particular, or indeterminate [Aristotle] |
| Full Idea: Affirming/denying sentences are universal, particular, or indeterminate. Belonging 'to every/to none' is universal; belonging 'to some/not to some/not to every' is particular; belonging or not belonging (without universal/particular) is indeterminate. | |
| From: Aristotle (Prior Analytics [c.328 BCE], 24a16) |
| 8079 | Aristotelian logic has two quantifiers of the subject ('all' and 'some') [Aristotle, by Devlin] |
| Full Idea: Aristotelian logic has two quantifiers of the subject ('all' and 'some'), and two ways to combine the subject with the predicate ('have', and 'have not'), giving four propositions: all-s-have-p, all-s-have-not-p, some-s-have-p, and some-s-have-not-p. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by Keith Devlin - Goodbye Descartes Ch.2 | |
| A reaction: Frege seems to have switched from 'some' to 'at-least-one'. Since then other quantifiers have been proposed. See, for example, Ideas 7806 and 6068. |
| 14641 | A deduction is necessary if the major (but not the minor) premise is also necessary [Aristotle] |
| Full Idea: It sometimes results that the deduction becomes necessary when only one of the premises is necessary (not whatever premise it might be, however, but only the premise in relation to the major extreme [premise]). | |
| From: Aristotle (Prior Analytics [c.328 BCE], 30a15) | |
| A reaction: The qualification is brackets is said by Plantinga (1969) to be a recognition of the de re/ de dicto distinction (later taken up by Aquinas). Plantinga gives two examples to illustrate his reading. |
| 18911 | Linguistic terms form a hierarchy, with higher terms predicable of increasing numbers of things [Aristotle, by Engelbretsen] |
| Full Idea: According to Aristotle, the terms of a language form a finite hierarchy, where the higher terms are predicable of more things than are lower terms. | |
| From: report of Aristotle (Prior Analytics [c.328 BCE]) by George Engelbretsen - Trees, Terms and Truth 3 | |
| A reaction: I would be a bit cautious about placing something precisely in a hierarchy according to how many things it can be predicated of. It is a start, though, in trying to give a decent account of generality, which is a major concept in philosophy. |
| 2705 | How can intuitionists distinguish universal convictions from local cultural ones? [Hare] |
| Full Idea: There are convictions which are common to most societies; but there are others which are not, and no way is given by intuitionists of telling which are the authoritative data. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.454) | |
| A reaction: It seems unfair on intuitionists to say they haven't given a way to evaluate such things, given that they have offered intuition. The issue is what exactly they mean by 'intuition'. |
| 2712 | You can't use intuitions to decide which intuitions you should cultivate [Hare] |
| Full Idea: If it comes to deciding what intuitions and dispositions to cultivate, we cannot rely on the intuitions themselves, as intuitionists do. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.461) | |
| A reaction: Makes intuitionists sound a bit dim. Surely Hume identifies dispositions (such as benevolence) which should be cultivated, because they self-evidently improve social life? |
| 2706 | Emotivists mistakenly think all disagreements are about facts, and so there are no moral reasons [Hare] |
| Full Idea: Emotivists concluded too hastily that because naturalism and intuitionism are false, you cannot reason about moral questions, because they assumed that the only questions you can reason about are factual ones. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.455) | |
| A reaction: Personally I have a naturalistic view of ethics (based on successful functioning, as indicated by Aristotle), so not my prob. Why can't we reason about expressive emotions? We reason about art. |
| 2709 | Prescriptivism sees 'ought' statements as imperatives which are universalisable [Hare] |
| Full Idea: Universal prescriptivists hold that 'ought'-judgements are prescriptive like plain imperatives, but differ from them in being universalisable. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.457) | |
| A reaction: Sounds a bit tautological. Which comes first, the normativity or the universalisability? |
| 2704 | If morality is just a natural or intuitive description, that leads to relativism [Hare] |
| Full Idea: Non-descriptivists (e.g. prescriptivists) reject descriptivism in its naturalist or intuitionist form, because they are both destined to collapse into relativism. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.453) | |
| A reaction: I'm not clear from this why prescriptism would not also turn out to be relativist, if it includes evaluations along with facts. |
| 2703 | Descriptivism say ethical meaning is just truth-conditions; prescriptivism adds an evaluation [Hare] |
| Full Idea: Ethical descriptivism is the view that ethical sentence-meaning is wholly determined by truth-conditions. …Prescriptivists think there is a further element of meaning, which expresses prescriptions or evaluations or attitudes which we assent to. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.452) | |
| A reaction: Not sure I understand either of these. If all meaning consists of truth-conditions, that will apply to ethics. If meaning includes evaluations, that will apply to non-ethics. |
| 2707 | If there can be contradictory prescriptions, then reasoning must be involved [Hare] |
| Full Idea: Prescriptivists claim that there are rules of reasoning which govern non-descriptive as well as descriptive speech acts. The standard example is possible logical inconsistency between contradictory prescriptions. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.455) | |
| A reaction: The example doesn't seem very good. Inconsistency can appear in any area of thought, but that isn't enough to infer full 'rules of reasoning'. I could desire two incompatible crazy things. |
| 2708 | An 'ought' statement implies universal application [Hare] |
| Full Idea: In any 'ought' statement there is implicit a principle which says that the statement applies to all precisely similar situations. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.456) | |
| A reaction: No two situations can ever be 'precisely' similar. Indeed, 'precisely similar' may be an oxymoron (at least for situations). Kantians presumably like this idea. |
| 2711 | Prescriptivism implies a commitment, but descriptivism doesn't [Hare] |
| Full Idea: Prescriptivists hold that moral judgements commit the speaker to motivations and actions, but non-moral facts by themselves do not do this. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.459) | |
| A reaction: Surely hunger motivates to action? I suppose the key word is 'commit'. But lazy people are allowed to make moral judgements. |
| 23874 | Armies and businesses create moralities in which their activity can do no wrong [Marx, by Weil] |
| Full Idea: Marx saw that social groups manufacture moralities for their own use, so their activity is placed outside the reach of evil. Thus the first articles of soldiers and businessmen is to deny that it is possible to do evil while waging war or doing business. | |
| From: report of Karl Marx (works [1860]) by Simone Weil - Fragments: London 1943 p.146 | |
| A reaction: This is especially true of the modern reverence for 'market forces'. It is a key debate in the ethics of warfare - compare Walzer and McMahon. A striking thought, obviously containing a lot of truth. |
| 2710 | Moral judgements must invoke some sort of principle [Hare] |
| Full Idea: To make moral judgements is implicitly to invoke some principle, however specific. | |
| From: Richard M. Hare (Universal Prescriptivism [1991], p.458) |
| 18662 | Liberal freedom is the right to be separate, and ignores the union of man with man [Marx] |
| Full Idea: The liberal right of man to freedom is not based on the union of man with man, but on the separation of man from man; it is the right to this separation. | |
| From: Karl Marx (works [1860]), quoted by Will Kymlicka - Contemporary Political Philosophy (1st edn) 7.2.a | |
| A reaction: [quoted from an anthology] It is interesting that liberal freedom is the right NOT to be involved in politics, and even not to vote in elections. Home counties England (high hedges etc) is the embodiment of the freedom not to be involved in society. |
| 23372 | Liberals want the right to be separate, rather than for people to be united [Marx] |
| Full Idea: The [liberal] right of man to freedom is not based on the union of man with man, but on the separation of man from man. It is the right to this separation. | |
| From: Karl Marx (works [1860], p.53), quoted by Will Kymlicka - Contemporary Political Philosophy (2nd edn) 7 | |
| A reaction: [in collection ed.McLelland p.53] That nicely encapsulates the debate. Modern liberal thinkers regret the loss of community, but people in authoritarian communities yearn for separation. You can have too much 'union'! |
| 20576 | Early Marx anticipates communitarian objections to liberalism [Marx, by Oksala] |
| Full Idea: The early writings of Marx anticipate the communitarian critique of liberalism. | |
| From: report of Karl Marx (works [1860]) by Johanna Oksala - Political Philosophy: all that matters Ch.8 | |
| A reaction: [Oksala says modern writers seem to prefer this to the hardcore later Marx, which is presumably too 'scientific'. He says 'Capital Vol 1' is Marx's most important work] |
| 23862 | By saying the material dialectic of history aspires to the best, Marx agreed with capitalism [Weil on Marx] |
| Full Idea: When Marx inverted Hegel's dialectic of history, by substituting matter for mind as the motive, he attributed to matter the essence of mind, an unceasing aspiration towards the best - which was in keeping with the general current of capitalist thought. | |
| From: comment on Karl Marx (works [1860]) by Simone Weil - Reflections on Liberty and Social Oppression p.43 | |
| A reaction: [compressed] A rather nice debating point! Marx seems to share the universal nineteenth century belief in unremitting progress. Without that, it is impossible to believe that a revolution will necessarily improve anything. |
| 21999 | False consciousness results from concealment by the superstructure [Marx, by Singer] |
| Full Idea: False consciousness involves failing to see things as they really are. It comes about because a society's superstructure can conceal the real basis of the society. | |
| From: report of Karl Marx (works [1860]) by Peter Singer - Marx 9 | |
| A reaction: That seems a poor label, probably revealing a Hegelian background. It seems a matter of knowledge rather than consciousness. Can a whole mind be in a state of error? |
| 23875 | Marx says force is everything, and that the weak will become strong, while remaining the weak [Weil on Marx] |
| Full Idea: Marx posits on the one hand that force alone governs social relations to the exclusion of anything else, and on the other hand that one day the weak, while remaining weak, will nevertheless be stronger. He believed in miracles. | |
| From: comment on Karl Marx (works [1860]) by Simone Weil - Fragments: London 1943 p.149 | |
| A reaction: This is close to the obvious contradiction if the working classes despise the middle classes (the dreaded 'bourgeoisie') while their only aspiration is to be like them. It is hard to custom design a new class to which they could both aspire. |
| 18653 | Marx rejected equal rights because they never actually treat people as equals [Marx, by Kymlicka] |
| Full Idea: Marx rejected the idea of equal rights, not because he was not a friend to the idea of treating people as equals, but precisely because he thought rights failed to live up to that ideal. | |
| From: report of Karl Marx (works [1860]) by Will Kymlicka - Contemporary Political Philosophy (1st edn) 5.1 | |
| A reaction: Presumably because the power to award 'rights' goes to the highest bidder. If equality is to be enshrined in law, it is a bit difficult to see how else to manage it. |
| 20958 | Capitalism changes the world, by socialising the idea of a commodity [Marx, by Bowie] |
| Full Idea: In Marx's view the essential factor in capitalism is that the encroachment of the commodity form into society fundamentally changes the world. | |
| From: report of Karl Marx (works [1860]) by Andrew Bowie - Introduction to German Philosophy 6 'Historical' | |
| A reaction: The main point is that people and their labour become commodities. Haven't animals always been treated as commodities? Clearly slave were commodities, long before capitalism. Capitalism universalises it? |
| 23876 | The essence of capitalism is the subordination of people to things [Marx, by Weil] |
| Full Idea: Marx discovered a formula impossible to surpass when he said that the essence of capitalism lies in the subordination of subject to object, of man to thing. | |
| From: report of Karl Marx (works [1860]) by Simone Weil - Fragments: London 1943 p,155 | |
| A reaction: I find this rather too vague to be a penetrating observation. I would suggest the obliteration of cooperation and community, in favour of competition. Winners and losers. |
| 20960 | Marx thought capitalism was partly liberating, and could make labour and ownership more humane [Marx, by Bowie] |
| Full Idea: Marx did not disapprove per se of capitalism. New divisions of labour and forms of ownership could transform individuals in modern societies, creating a more humane world with the means capitalism had liberated from feudalism. | |
| From: report of Karl Marx (works [1860]) by Andrew Bowie - Introduction to German Philosophy 11 'Metaphysics' | |
| A reaction: I'm guessing this might be early Marx, which has less to say about the 'scientific' inevitably of deep change, and the necessity for revolution. Nowadays we tinker with humane changes at the poorer end, while the rich run rampant. |