122 ideas
19693 | There is practical wisdom (for action), and theoretical wisdom (for deep understanding) [Aristotle, by Whitcomb] |
2512 | Philosophy is a battle against the bewitchment of our intelligence by means of language [Wittgenstein] |
4148 | What is your aim in philosophy? - To show the fly the way out of the fly-bottle [Wittgenstein] |
22490 | Bring words back from metaphysics to everyday use [Wittgenstein] |
1575 | For Aristotle logos is essentially the ability to talk rationally about questions of value [Roochnik on Aristotle] |
1589 | Aristotle is the supreme optimist about the ability of logos to explain nature [Roochnik on Aristotle] |
6566 | The problem is to explain the role of contradiction in social life [Wittgenstein] |
8200 | Aristotelian definitions aim to give the essential properties of the thing defined [Aristotle, by Quine] |
4385 | Aristotelian definition involves first stating the genus, then the differentia of the thing [Aristotle, by Urmson] |
9738 | Each line of a truth table is a model [Fitting/Mendelsohn] |
9727 | Modal logic adds □ (necessarily) and ◊ (possibly) to classical logic [Fitting/Mendelsohn] |
9726 | We let 'R' be the accessibility relation: xRy is read 'y is accessible from x' [Fitting/Mendelsohn] |
9737 | The symbol ||- is the 'forcing' relation; 'Γ ||- P' means that P is true in world Γ [Fitting/Mendelsohn] |
13136 | The prefix σ names a possible world, and σ.n names a world accessible from that one [Fitting/Mendelsohn] |
13727 | A 'constant' domain is the same for all worlds; 'varying' domains can be entirely separate [Fitting/Mendelsohn] |
9734 | Modern modal logic introduces 'accessibility', saying xRy means 'y is accessible from x' [Fitting/Mendelsohn] |
9736 | A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn] |
9735 | A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn] |
9741 | Accessibility relations can be 'reflexive' (self-referring), 'transitive' (carries over), or 'symmetric' (mutual) [Fitting/Mendelsohn] |
9740 | If a proposition is possibly true in a world, it is true in some world accessible from that world [Fitting/Mendelsohn] |
9739 | If a proposition is necessarily true in a world, it is true in all worlds accessible from that world [Fitting/Mendelsohn] |
13137 | Conj: a) if σ X∧Y then σ X and σ Y b) if σ ¬(X∧Y) then σ ¬X or σ ¬Y [Fitting/Mendelsohn] |
13140 | Bicon: a)if σ(X↔Y) then σ(X→Y) and σ(Y→X) b) [not biconditional, one or other fails] [Fitting/Mendelsohn] |
13139 | Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y [Fitting/Mendelsohn] |
13143 | Universal: a) if σ ¬◊X then σ.m ¬X b) if σ □X then σ.m X [m exists] [Fitting/Mendelsohn] |
13149 | S5: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X [Fitting/Mendelsohn] |
13141 | Negation: if σ ¬¬X then σ X [Fitting/Mendelsohn] |
13138 | Disj: a) if σ ¬(X∨Y) then σ ¬X and σ ¬Y b) if σ X∨Y then σ X or σ Y [Fitting/Mendelsohn] |
13142 | Existential: a) if σ ◊X then σ.n X b) if σ ¬□X then σ.n ¬X [n is new] [Fitting/Mendelsohn] |
13144 | T reflexive: a) if σ □X then σ X b) if σ ¬◊X then σ ¬X [Fitting/Mendelsohn] |
13145 | D serial: a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X [Fitting/Mendelsohn] |
13146 | B symmetric: a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [n occurs] [Fitting/Mendelsohn] |
13147 | 4 transitive: a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [n occurs] [Fitting/Mendelsohn] |
13148 | 4r rev-trans: a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [n occurs] [Fitting/Mendelsohn] |
9742 | The system K has no accessibility conditions [Fitting/Mendelsohn] |
13114 | □P → P is not valid in D (Deontic Logic), since an obligatory action may be not performed [Fitting/Mendelsohn] |
9743 | The system D has the 'serial' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
9744 | The system T has the 'reflexive' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
9746 | The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn] |
9745 | The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn] |
9747 | The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
9748 | System S5 has the 'reflexive', 'symmetric' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
9404 | Modality affects content, because P→◊P is valid, but ◊P→P isn't [Fitting/Mendelsohn] |
13112 | In epistemic logic knowers are logically omniscient, so they know that they know [Fitting/Mendelsohn] |
13111 | Read epistemic box as 'a knows/believes P' and diamond as 'for all a knows/believes, P' [Fitting/Mendelsohn] |
13113 | F: will sometime, P: was sometime, G: will always, H: was always [Fitting/Mendelsohn] |
13728 | The Barcan says nothing comes into existence; the Converse says nothing ceases; the pair imply stability [Fitting/Mendelsohn] |
13729 | The Barcan corresponds to anti-monotonicity, and the Converse to monotonicity [Fitting/Mendelsohn] |
13282 | Aristotle relativises the notion of wholeness to different measures [Aristotle, by Koslicki] |
4730 | For Aristotle, the subject-predicate structure of Greek reflected a substance-accident structure of reality [Aristotle, by O'Grady] |
18743 | Wittgenstein says we want the grammar of problems, not their first-order logical structure [Wittgenstein, by Horsten/Pettigrew] |
4139 | Naming is a preparation for description [Wittgenstein] |
4946 | A name is not determined by a description, but by a cluster or family [Wittgenstein, by Kripke] |
9725 | 'Predicate abstraction' abstracts predicates from formulae, giving scope for constants and functions [Fitting/Mendelsohn] |
13276 | The unmoved mover and the soul show Aristotelian form as the ultimate mereological atom [Aristotle, by Koslicki] |
13277 | The 'form' is the recipe for building wholes of a particular kind [Aristotle, by Koslicki] |
15106 | Essence is expressed by grammar [Wittgenstein] |
13730 | The Indiscernibility of Identicals has been a big problem for modal logic [Fitting/Mendelsohn] |
13725 | □ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn] |
13731 | Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn] |
13726 | Counterpart relations are neither symmetric nor transitive, so there is no logic of equality for them [Fitting/Mendelsohn] |
5991 | For Aristotle, knowledge is of causes, and is theoretical, practical or productive [Aristotle, by Code] |
6600 | The belief that fire burns is like the fear that it burns [Wittgenstein] |
4153 | Are sense-data the material of which the universe is made? [Wittgenstein] |
11239 | The notion of a priori truth is absent in Aristotle [Aristotle, by Politis] |
6501 | As sense-data are necessarily private, they are attacked by Wittgenstein's objections [Wittgenstein, by Robinson,H] |
23312 | Aristotle is a rationalist, but reason is slowly acquired through perception and experience [Aristotle, by Frede,M] |
16111 | Aristotle wants to fit common intuitions, and therefore uses language as a guide [Aristotle, by Gill,ML] |
11079 | How do I decide when to accept or obey an intuition? [Wittgenstein] |
4160 | One can mistrust one's own senses, but not one's own beliefs [Wittgenstein] |
16971 | Plato says sciences are unified around Forms; Aristotle says they're unified around substance [Aristotle, by Moravcsik] |
11243 | Aristotelian explanations are facts, while modern explanations depend on human conceptions [Aristotle, by Politis] |
3320 | Aristotle's standard analysis of species and genus involves specifying things in terms of something more general [Aristotle, by Benardete,JA] |
12000 | Aristotle regularly says that essential properties explain other significant properties [Aristotle, by Kung] |
19273 | I don't have the opinion that people have minds; I just treat them as such [Wittgenstein] |
5663 | It is irresponsible to generalise from my own case of pain to other people's [Wittgenstein] |
19272 | To imagine another's pain by my own, I must imagine a pain I don't feel, by one I do feel [Wittgenstein] |
4161 | If a lion could talk, we could not understand him [Wittgenstein] |
7392 | If a lion could talk, it would be nothing like other lions [Dennett on Wittgenstein] |
5676 | To say that I 'know' I am in pain means nothing more than that I AM in pain [Wittgenstein] |
4154 | Why are we not aware of the huge gap between mind and brain in ordinary life? [Wittgenstein] |
23300 | Aristotle and the Stoics denied rationality to animals, while Platonists affirmed it [Aristotle, by Sorabji] |
4158 | An 'inner process' stands in need of outward criteria [Wittgenstein] |
6165 | Every course of action can either accord or conflict with a rule, so there is no accord or conflict [Wittgenstein] |
4143 | One cannot obey a rule 'privately', because that is a practice, not the same as thinking one is obeying [Wittgenstein] |
7092 | If individuals can't tell if they are following a rule, how does a community do it? [Grayling on Wittgenstein] |
4138 | Is white simple, or does it consist of the colours of the rainbow? [Wittgenstein] |
7055 | Externalist accounts of mental content begin in Wittgenstein [Wittgenstein, by Heil] |
12576 | Possessing a concept is knowing how to go on [Wittgenstein, by Peacocke] |
4157 | Concepts direct our interests and investigations, and express those interests [Wittgenstein] |
12606 | Man learns the concept of the past by remembering [Wittgenstein] |
4141 | Various games have a 'family resemblance', as their similarities overlap and criss-cross [Wittgenstein] |
23450 | Wittgenstein rejected his earlier view that the form of language is the form of the world [Wittgenstein, by Morris,M] |
4150 | Asking about verification is only one way of asking about the meaning of a proposition [Wittgenstein] |
6567 | For Wittgenstein, words are defined by their use, just as chess pieces are [Wittgenstein, by Fogelin] |
6169 | We do not achieve meaning and understanding in our heads, but in the world [Wittgenstein, by Rowlands] |
4155 | We all seem able to see quite clearly how sentences represent things when we use them [Wittgenstein] |
4137 | In the majority of cases the meaning of a word is its use in the language [Wittgenstein] |
4142 | To understand a sentence means to understand a language [Wittgenstein] |
4149 | We don't have 'meanings' in our minds in addition to verbal expressions [Wittgenstein] |
4156 | Make the following experiment: say "It's cold here" and mean "It's warm here" [Wittgenstein] |
4145 | How do words refer to sensations? [Wittgenstein] |
4140 | The standard metre in Paris is neither one metre long nor not one metre long [Wittgenstein] |
11240 | The notion of analytic truth is absent in Aristotle [Aristotle, by Politis] |
4136 | To imagine a language means to imagine a form of life [Wittgenstein] |
6166 | Was Wittgenstein's problem between individual and community, or between occasions for an individual? [Rowlands on Wittgenstein] |
7875 | If a brilliant child invented a name for a private sensation, it couldn't communicate it [Wittgenstein] |
4146 | We cannot doublecheck mental images for correctness (or confirm news with many copies of the paper) [Wittgenstein] |
4147 | If we only named pain by our own case, it would be like naming beetles by looking in a private box [Wittgenstein] |
5659 | If the reference is private, that is incompatible with the sense being public [Wittgenstein, by Scruton] |
4152 | Getting from perceptions to words cannot be a private matter; the rules need an institution of use [Wittgenstein] |
4144 | Common human behaviour enables us to interpret an unknown language [Wittgenstein] |
11049 | To communicate, language needs agreement in judgment as well as definition [Wittgenstein] |
6658 | What is left over if I subtract my arm going up from my raising my arm? [Wittgenstein] |
6559 | Aristotle never actually says that man is a rational animal [Aristotle, by Fogelin] |
11150 | It is the mark of an educated mind to be able to entertain an idea without accepting it [Aristotle] |
3037 | Aristotle said the educated were superior to the uneducated as the living are to the dead [Aristotle, by Diog. Laertius] |
8660 | There are potential infinities (never running out), but actual infinity is incoherent [Aristotle, by Friend] |
12058 | Aristotle's matter can become any other kind of matter [Aristotle, by Wiggins] |
22729 | The concepts of gods arose from observing the soul, and the cosmos [Aristotle, by Sext.Empiricus] |
4151 | Grammar tells what kind of object anything is - and theology is a kind of grammar [Wittgenstein] |
4159 | The human body is the best picture of the human soul [Wittgenstein] |