58 ideas
| 1597 | Thales was the first western thinker to believe the arché was intelligible [Roochnik on Thales] |
| 4901 | Truth has to be correspondence to facts, and a match between relations of ideas and relations in the world [Perry] |
| 9456 | Modal logic is multiple systems, shown in the variety of accessibility relations between worlds [Jacquette] |
| 7689 | The modal logic of C.I.Lewis was only interpreted by Kripke and Hintikka in the 1960s [Jacquette] |
| 9457 | The two main views in philosophy of logic are extensionalism and intensionalism [Jacquette] |
| 7681 | Logic describes inferences between sentences expressing possible properties of objects [Jacquette] |
| 9463 | Classical logic is bivalent, has excluded middle, and only quantifies over existent objects [Jacquette] |
| 7682 | Logic is not just about signs, because it relates to states of affairs, objects, properties and truth-values [Jacquette] |
| 7697 | On Russell's analysis, the sentence "The winged horse has wings" comes out as false [Jacquette] |
| 9466 | Nominalists like substitutional quantification to avoid the metaphysics of objects [Jacquette] |
| 9465 | Substitutional universal quantification retains truth for substitution of terms of the same type [Jacquette] |
| 9458 | Extensionalists say that quantifiers presuppose the existence of their objects [Jacquette] |
| 9461 | Intensionalists say meaning is determined by the possession of properties [Jacquette] |
| 7701 | Can a Barber shave all and only those persons who do not shave themselves? [Jacquette] |
| 7707 | To grasp being, we must say why something exists, and why there is one world [Jacquette] |
| 7692 | Being is maximal consistency [Jacquette] |
| 7687 | Existence is completeness and consistency [Jacquette] |
| 7679 | Ontology is the same as the conceptual foundations of logic [Jacquette] |
| 7678 | Ontology must include the minimum requirements for our semantics [Jacquette] |
| 7683 | Logic is based either on separate objects and properties, or objects as combinations of properties [Jacquette] |
| 7684 | Reduce states-of-affairs to object-property combinations, and possible worlds to states-of-affairs [Jacquette] |
| 7703 | If classes can't be eliminated, and they are property combinations, then properties (universals) can't be either [Jacquette] |
| 7685 | An object is a predication subject, distinguished by a distinctive combination of properties [Jacquette] |
| 7699 | Numbers, sets and propositions are abstract particulars; properties, qualities and relations are universals [Jacquette] |
| 4885 | Identity is a very weak relation, which doesn't require interdefinability, or shared properties [Perry] |
| 12155 | Statements of 'relative identity' are really statements of resemblance [Perry] |
| 3013 | Nothing is stronger than necessity, which rules everything [Thales, by Diog. Laertius] |
| 4899 | Possible worlds thinking has clarified the logic of modality, but is problematic in epistemology [Perry] |
| 7691 | The actual world is a consistent combination of states, made of consistent property combinations [Jacquette] |
| 4898 | Possible worlds are indices for a language, or concrete realities, or abstract possibilities [Perry] |
| 7688 | The actual world is a maximally consistent combination of actual states of affairs [Jacquette] |
| 7695 | Do proposition-structures not associated with the actual world deserve to be called worlds? [Jacquette] |
| 7694 | We must experience the 'actual' world, which is defined by maximally consistent propositions [Jacquette] |
| 12149 | Indexicals are a problem for beliefs being just subject-proposition relations [Perry] |
| 4887 | We try to cause other things to occur by causing mental events to occur [Perry] |
| 4884 | Brain states must be in my head, and yet the pain seems to be in my hand [Perry] |
| 4888 | It seems plausible that many animals have experiences without knowing about them [Perry] |
| 7706 | If qualia supervene on intentional states, then intentional states are explanatorily fundamental [Jacquette] |
| 4891 | If epiphenomenalism just says mental events are effects but not causes, it is consistent with physicalism [Perry] |
| 4900 | Prior to Kripke, the mind-brain identity theory usually claimed that the identity was contingent [Perry] |
| 7704 | Reduction of intentionality involving nonexistent objects is impossible, as reduction must be to what is actual [Jacquette] |
| 4892 | If physicalists stick with identity (not supervenience), Martian pain will not be like ours [Perry] |
| 16391 | Indexical thoughts are about themselves, and ascribe properties to themselves [Perry, by Recanati] |
| 4889 | Although we may classify ideas by content, we individuate them differently, as their content can change [Perry] |
| 4896 | The intension of an expression is a function from possible worlds to an appropriate extension [Perry] |
| 9460 | Extensionalist semantics forbids reference to nonexistent objects [Jacquette] |
| 9459 | Extensionalist semantics is circular, as we must know the extension before assessing 'Fa' [Jacquette] |
| 12151 | If we replace 'I' in sentences about me, they are different beliefs and explanations of behaviour [Perry] |
| 18412 | Indexicals individuate certain belief states, helping in explanation and prediction [Perry] |
| 7702 | The extreme views on propositions are Frege's Platonism and Quine's extreme nominalism [Jacquette] |
| 4897 | A proposition is a set of possible worlds for which its intension delivers truth [Perry] |
| 12150 | Indexicals reveal big problems with the traditional idea of a proposition [Perry] |
| 4890 | A sharp analytic/synthetic line can rarely be drawn, but some concepts are central to thought [Perry] |
| 1494 | Thales said water is the first principle, perhaps from observing that food is moist [Thales, by Aristotle] |
| 1713 | Thales must have thought soul causes movement, since he thought magnets have soul [Thales, by Aristotle] |
| 15203 | Tense is essential for thought and action [Perry, by Le Poidevin] |
| 15204 | Actual tensed sentences cannot be tenseless, because they can cite their own context [Perry, by Le Poidevin] |
| 1742 | Thales said the gods know our wrong thoughts as well as our evil actions [Thales, by Diog. Laertius] |