33 ideas
16877 | A 'constructive' (as opposed to 'analytic') definition creates a new sign [Frege] |
11219 | Frege suggested that mathematics should only accept stipulative definitions [Frege, by Gupta] |
16878 | We must be clear about every premise and every law used in a proof [Frege] |
16867 | Logic not only proves things, but also reveals logical relations between them [Frege] |
16863 | Does some mathematical reasoning (such as mathematical induction) not belong to logic? [Frege] |
16862 | The closest subject to logic is mathematics, which does little apart from drawing inferences [Frege] |
16865 | 'Theorems' are both proved, and used in proofs [Frege] |
16866 | Tracing inference backwards closes in on a small set of axioms and postulates [Frege] |
16868 | The essence of mathematics is the kernel of primitive truths on which it rests [Frege] |
16871 | A truth can be an axiom in one system and not in another [Frege] |
16870 | Axioms are truths which cannot be doubted, and for which no proof is needed [Frege] |
16869 | To create order in mathematics we need a full system, guided by patterns of inference [Frege] |
16864 | If principles are provable, they are theorems; if not, they are axioms [Frege] |
16435 | Plantinga proposes necessary existent essences as surrogates for the nonexistent things [Plantinga, by Stalnaker] |
14655 | The 'identity criteria' of a name are a group of essential and established facts [Plantinga] |
14658 | 'Being Socrates' and 'being identical with Socrates' characterise Socrates, so they are among his properties [Plantinga] |
9388 | Every concept must have a sharp boundary; we cannot allow an indeterminate third case [Frege] |
14656 | Does Socrates have essential properties, plus a unique essence (or 'haecceity') which entails them? [Plantinga] |
14654 | Properties are 'trivially essential' if they are instantiated by every object in every possible world [Plantinga] |
14653 | X is essentially P if it is P in every world, or in every X-world, or in the actual world (and not ¬P elsewhere) [Plantinga] |
14660 | If a property is ever essential, can it only ever be an essential property? [Plantinga] |
14661 | Essences are instantiated, and are what entails a thing's properties and lack of properties [Plantinga] |
14657 | Does 'being identical with Socrates' name a property? I can think of no objections to it [Plantinga] |
14652 | 'De re' modality is as clear as 'de dicto' modality, because they are logically equivalent [Plantinga] |
14659 | We can imagine being beetles or alligators, so it is possible we might have such bodies [Plantinga] |
3158 | Theories of intentionality presuppose rationality, so can't explain it [Dennett] |
3159 | Beliefs and desires aren't real; they are prediction techniques [Dennett] |
16876 | We need definitions to cram retrievable sense into a signed receptacle [Frege] |
16875 | We use signs to mark receptacles for complex senses [Frege] |
16879 | A sign won't gain sense just from being used in sentences with familiar components [Frege] |
16873 | Thoughts are not subjective or psychological, because some thoughts are the same for us all [Frege] |
16872 | A thought is the sense expressed by a sentence, and is what we prove [Frege] |
16874 | The parts of a thought map onto the parts of a sentence [Frege] |