58 ideas
| 11832 | We learn a concept's relations by using it, without reducing it to anything [Wiggins] |
| 22271 | Aristotle was the first to use schematic letters in logic [Aristotle, by Potter] |
| 11060 | Aristotelian syllogisms are three-part, subject-predicate, existentially committed, with laws of thought [Aristotle, by Hanna] |
| 18909 | Aristotelian sentences are made up by one of four 'formative' connectors [Aristotle, by Engelbretsen] |
| 8080 | Aristotelian identified 256 possible syllogisms, saying that 19 are valid [Aristotle, by Devlin] |
| 13912 | Aristotle replaced Plato's noun-verb form with unions of pairs of terms by one of four 'copulae' [Aristotle, by Engelbretsen/Sayward] |
| 8071 | Aristotle listed nineteen valid syllogisms (though a few of them were wrong) [Aristotle, by Devlin] |
| 13819 | Aristotle's said some Fs are G or some Fs are not G, forgetting that there might be no Fs [Bostock on Aristotle] |
| 9403 | There are three different deductions for actual terms, necessary terms and possible terms [Aristotle] |
| 11148 | Deduction is when we suppose one thing, and another necessarily follows [Aristotle] |
| 18896 | Aristotle places terms at opposite ends, joined by a quantified copula [Aristotle, by Sommers] |
| 3300 | Aristotle's logic is based on the subject/predicate distinction, which leads him to substances and properties [Aristotle, by Benardete,JA] |
| 11863 | (λx)[Man x] means 'the property x has iff x is a man'. [Wiggins] |
| 11149 | Affirming/denying sentences are universal, particular, or indeterminate [Aristotle] |
| 8079 | Aristotelian logic has two quantifiers of the subject ('all' and 'some') [Aristotle, by Devlin] |
| 14746 | What exists can't depend on our conceptual scheme, and using all conceptual schemes is too liberal [Sider on Wiggins] |
| 11900 | We can accept criteria of distinctness and persistence, without making the counterfactual claims [Mackie,P on Wiggins] |
| 11870 | Activity individuates natural things, functions do artefacts, and intentions do artworks [Wiggins] |
| 11866 | The idea of 'thisness' is better expressed with designation/predication and particular/universal [Wiggins] |
| 11896 | A sortal essence is a thing's principle of individuation [Wiggins, by Mackie,P] |
| 15835 | Wiggins's sortal essentialism rests on a thing's principle of individuation [Wiggins, by Mackie,P] |
| 11841 | The evening star is the same planet but not the same star as the morning star, since it is not a star [Wiggins] |
| 10679 | 'Sortalism' says parts only compose a whole if it falls under a sort or kind [Wiggins, by Hossack] |
| 14363 | Identity a=b is only possible with some concept to give persistence and existence conditions [Wiggins, by Strawson,P] |
| 14364 | A thing is necessarily its highest sortal kind, which entails an essential constitution [Wiggins, by Strawson,P] |
| 11851 | Many predicates are purely generic, or pure determiners, rather than sortals [Wiggins] |
| 11865 | The possibility of a property needs an essential sortal concept to conceive it [Wiggins] |
| 12699 | A body would be endless disunited parts, if it did not have a unifying form or soul [Leibniz] |
| 14744 | Objects can only coincide if they are of different kinds; trees can't coincide with other trees [Wiggins, by Sider] |
| 11852 | Is the Pope's crown one crown, if it is made of many crowns? [Wiggins] |
| 11875 | Boundaries are not crucial to mountains, so they are determinate without a determinate extent [Wiggins] |
| 12700 | Form or soul gives unity and duration; matter gives multiplicity and change [Leibniz] |
| 14749 | Identity is an atemporal relation, but composition is relative to times [Wiggins, by Sider] |
| 11844 | If I destroy an item, I do not destroy each part of it [Wiggins] |
| 11861 | We can forget about individual or particularized essences [Wiggins] |
| 11871 | Essences are not explanations, but individuations [Wiggins] |
| 11879 | Essentialism is best represented as a predicate-modifier: □(a exists → a is F) [Wiggins, by Mackie,P] |
| 11835 | The nominal essence is the idea behind a name used for sorting [Wiggins] |
| 11876 | It is easier to go from horses to horse-stages than from horse-stages to horses [Wiggins] |
| 11858 | The question is not what gets the title 'Theseus' Ship', but what is identical with the original [Wiggins] |
| 11843 | Identity over a time and at a time aren't different concepts [Wiggins] |
| 11864 | Hesperus=Hesperus, and Phosphorus=Hesperus, so necessarily Phosphorus=Hesperus [Wiggins] |
| 11831 | The formal properties of identity are reflexivity and Leibniz's Law [Wiggins] |
| 14362 | Relative Identity is incompatible with the Indiscernibility of Identicals [Wiggins, by Strawson,P] |
| 11838 | Relativity of Identity makes identity entirely depend on a category [Wiggins] |
| 11847 | To identify two items, we must have a common sort for them [Wiggins] |
| 11839 | Do both 'same f as' and '=' support Leibniz's Law? [Wiggins] |
| 11845 | Substitutivity, and hence most reasoning, needs Leibniz's Law [Wiggins] |
| 14641 | A deduction is necessary if the major (but not the minor) premise is also necessary [Aristotle] |
| 12736 | If we understand God and his choices, we have a priori knowledge of contingent truths [Leibniz, by Garber] |
| 11869 | Possible worlds rest on the objects about which we have suppositions [Wiggins] |
| 11850 | Not every story corresponds to a possible world [Wiggins] |
| 11848 | Asking 'what is it?' nicely points us to the persistence of a continuing entity [Wiggins] |
| 18911 | Linguistic terms form a hierarchy, with higher terms predicable of increasing numbers of things [Aristotle, by Engelbretsen] |
| 12698 | Every body contains a kind of sense and appetite, or a soul [Leibniz] |
| 11859 | The mind conceptualizes objects; yet objects impinge upon the mind [Wiggins] |
| 11836 | We can use 'concept' for the reference, and 'conception' for sense [Wiggins] |
| 11860 | Lawlike propensities are enough to individuate natural kinds [Wiggins] |