40 ideas
14273 | Conditional Proof is only valid if we accept the truth-functional reading of 'if' [Edgington] |
12204 | The logic of metaphysical necessity is S5 [Rumfitt] |
12195 | Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt] |
12199 | There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt] |
12201 | We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt] |
12194 | Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt] |
12198 | Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt] |
17518 | Counting 'coin in this box' may have coin as the unit, with 'in this box' merely as the scope [Ayers] |
17516 | If counting needs a sortal, what of things which fall under two sortals? [Ayers] |
17520 | Events do not have natural boundaries, and we have to set them [Ayers] |
17519 | To express borderline cases of objects, you need the concept of an 'object' [Ayers] |
17510 | Speakers need the very general category of a thing, if they are to think about it [Ayers] |
17522 | We use sortals to classify physical objects by the nature and origin of their unity [Ayers] |
17515 | Seeing caterpillar and moth as the same needs continuity, not identity of sortal concepts [Ayers] |
17511 | Recognising continuity is separate from sortals, and must precede their use [Ayers] |
17517 | Could the same matter have more than one form or principle of unity? [Ayers] |
17513 | If there are two objects, then 'that marble, man-shaped object' is ambiguous [Ayers] |
17523 | Sortals basically apply to individuals [Ayers] |
17521 | You can't have the concept of a 'stage' if you lack the concept of an object [Ayers] |
17514 | Temporal 'parts' cannot be separated or rearranged [Ayers] |
17509 | Some say a 'covering concept' completes identity; others place the concept in the reference [Ayers] |
17512 | If diachronic identities need covering concepts, why not synchronic identities too? [Ayers] |
14532 | A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A] |
12193 | Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt] |
12200 | A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt] |
12202 | Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt] |
14281 | A thing works like formal probability if all the options sum to 100% [Edgington] |
14284 | Conclusion improbability can't exceed summed premise improbability in valid arguments [Edgington] |
14270 | Simple indicatives about past, present or future do seem to form a single semantic kind [Edgington] |
14269 | Maybe forward-looking indicatives are best classed with the subjunctives [Edgington] |
14275 | Truth-function problems don't show up in mathematics [Edgington] |
14274 | Inferring conditionals from disjunctions or negated conjunctions gives support to truth-functionalism [Edgington] |
14276 | The truth-functional view makes conditionals with unlikely antecedents likely to be true [Edgington] |
14290 | Doctor:'If patient still alive, change dressing'; Nurse:'Either dead patient, or change dressing'; kills patient! [Edgington] |
14271 | Non-truth-functionalist say 'If A,B' is false if A is T and B is F, but deny that is always true for TT,FT and FF [Edgington] |
14272 | I say "If you touch that wire you'll get a shock"; you don't touch it. How can that make the conditional true? [Edgington] |
14282 | On the supposition view, believe if A,B to the extent that A&B is nearly as likely as A [Edgington] |
14278 | Truth-functionalists support some conditionals which we assert, but should not actually believe [Edgington] |
14287 | Does 'If A,B' say something different in each context, because of the possibiites there? [Edgington] |
12203 | If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt] |