64 ideas
| 18005 | Philosophy aims to become more disciplined about categories [Ryle] |
| 9123 | Someone standing in a doorway seems to be both in and not-in the room [Priest,G, by Sorensen] |
| 18004 | We can't do philosophy without knowledge of types and categories [Ryle] |
| 13985 | A true proposition seems true of one fact, but a false proposition seems true of nothing at all. [Ryle] |
| 13984 | Two maps might correspond to one another, but they are only 'true' of the country they show [Ryle] |
| 8720 | A logic is 'relevant' if premise and conclusion are connected, and 'paraconsistent' allows contradictions [Priest,G, by Friend] |
| 9672 | Free logic is one of the few first-order non-classical logics [Priest,G] |
| 9697 | X1 x X2 x X3... x Xn indicates the 'cartesian product' of those sets [Priest,G] |
| 9685 | <a,b&62; is a set whose members occur in the order shown [Priest,G] |
| 9675 | a ∈ X says a is an object in set X; a ∉ X says a is not in X [Priest,G] |
| 9674 | {x; A(x)} is a set of objects satisfying the condition A(x) [Priest,G] |
| 9673 | {a1, a2, ...an} indicates that a set comprising just those objects [Priest,G] |
| 9677 | Φ indicates the empty set, which has no members [Priest,G] |
| 9676 | {a} is the 'singleton' set of a (not the object a itself) [Priest,G] |
| 9679 | X⊂Y means set X is a 'proper subset' of set Y [Priest,G] |
| 9678 | X⊆Y means set X is a 'subset' of set Y [Priest,G] |
| 9681 | X = Y means the set X equals the set Y [Priest,G] |
| 9683 | X ∩ Y indicates the 'intersection' of sets X and Y, the objects which are in both sets [Priest,G] |
| 9682 | X∪Y indicates the 'union' of all the things in sets X and Y [Priest,G] |
| 9684 | Y - X is the 'relative complement' of X with respect to Y; the things in Y that are not in X [Priest,G] |
| 9694 | The 'relative complement' is things in the second set not in the first [Priest,G] |
| 9693 | The 'intersection' of two sets is a set of the things that are in both sets [Priest,G] |
| 9692 | The 'union' of two sets is a set containing all the things in either of the sets [Priest,G] |
| 9698 | The 'induction clause' says complex formulas retain the properties of their basic formulas [Priest,G] |
| 9695 | An 'ordered pair' (or ordered n-tuple) is a set with its members in a particular order [Priest,G] |
| 9696 | A 'cartesian product' of sets is the set of all the n-tuples with one member in each of the sets [Priest,G] |
| 9686 | A 'set' is a collection of objects [Priest,G] |
| 9689 | The 'empty set' or 'null set' has no members [Priest,G] |
| 9690 | A set is a 'subset' of another set if all of its members are in that set [Priest,G] |
| 9691 | A 'proper subset' is smaller than the containing set [Priest,G] |
| 9688 | A 'singleton' is a set with only one member [Priest,G] |
| 9687 | A 'member' of a set is one of the objects in the set [Priest,G] |
| 9680 | The empty set Φ is a subset of every set (including itself) [Priest,G] |
| 13979 | Logic studies consequence, compatibility, contradiction, corroboration, necessitation, grounding.... [Ryle] |
| 10800 | The values of variables can't determine existence, because they are just expressions [Ryle, by Quine] |
| 13373 | Typically, paradoxes are dealt with by dividing them into two groups, but the division is wrong [Priest,G] |
| 13368 | The 'least indefinable ordinal' is defined by that very phrase [Priest,G] |
| 13370 | 'x is a natural number definable in less than 19 words' leads to contradiction [Priest,G] |
| 13369 | By diagonalization we can define a real number that isn't in the definable set of reals [Priest,G] |
| 13366 | The least ordinal greater than the set of all ordinals is both one of them and not one of them [Priest,G] |
| 13367 | The next set up in the hierarchy of sets seems to be both a member and not a member of it [Priest,G] |
| 13371 | If you know that a sentence is not one of the known sentences, you know its truth [Priest,G] |
| 13372 | There are Liar Pairs, and Liar Chains, which fit the same pattern as the basic Liar [Priest,G] |
| 13988 | Many sentences do not state facts, but there are no facts which could not be stated [Ryle] |
| 14297 | A dispositional property is not a state, but a liability to be in some state, given a condition [Ryle] |
| 14300 | No physical scientist now believes in an occult force-exerting agency [Ryle] |
| 13983 | Representation assumes you know the ideas, and the reality, and the relation between the two [Ryle] |
| 3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
| 2622 | Can one movement have a mental and physical cause? [Ryle] |
| 1353 | Reporting on myself has the same problems as reporting on you [Ryle] |
| 1354 | We cannot introspect states of anger or panic [Ryle] |
| 2624 | I cannot prepare myself for the next thought I am going to think [Ryle] |
| 2620 | Dualism is a category mistake [Ryle] |
| 2388 | Behaviour depends on desires as well as beliefs [Chalmers on Ryle] |
| 3354 | You can't explain mind as dispositions, if they aren't real [Benardete,JA on Ryle] |
| 2387 | How can behaviour be the cause of behaviour? [Chalmers on Ryle] |
| 13980 | If you like judgments and reject propositions, what are the relata of incoherence in a judgment? [Ryle] |
| 13978 | Husserl and Meinong wanted objective Meanings and Propositions, as subject-matter for Logic [Ryle] |
| 13977 | When I utter a sentence, listeners grasp both my meaning and my state of mind [Ryle] |
| 13976 | 'Propositions' name what is thought, because 'thoughts' and 'judgments' are too ambiguous [Ryle] |
| 13981 | Several people can believe one thing, or make the same mistake, or share one delusion [Ryle] |
| 13987 | We may think in French, but we don't know or believe in French [Ryle] |
| 13989 | There are no propositions; they are just sentences, used for thinking, which link to facts in a certain way [Ryle] |
| 13982 | If we accept true propositions, it is hard to reject false ones, and even nonsensical ones [Ryle] |