32 ideas
5035 | The two basics of reasoning are contradiction and sufficient reason [Leibniz] |
1708 | In "Callias is just/not just/unjust", which of these are contraries? [Aristotle] |
1703 | It is necessary that either a sea-fight occurs tomorrow or it doesn't, though neither option is in itself necessary [Aristotle] |
1704 | Statements are true according to how things actually are [Aristotle] |
22272 | Aristotle's later logic had to treat 'Socrates' as 'everything that is Socrates' [Potter on Aristotle] |
9405 | Square of Opposition: not both true, or not both false; one-way implication; opposite truth-values [Aristotle] |
9728 | Modal Square 1: □P and ¬◊¬P are 'contraries' of □¬P and ¬◊P [Aristotle, by Fitting/Mendelsohn] |
9729 | Modal Square 2: ¬□¬P and ◊P are 'subcontraries' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
9730 | Modal Square 3: □P and ¬◊¬P are 'contradictories' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
9731 | Modal Square 4: □¬P and ¬◊P are 'contradictories' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn] |
9732 | Modal Square 5: □P and ¬◊¬P are 'subalternatives' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn] |
9733 | Modal Square 6: □¬P and ¬◊P are 'subalternatives' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
5745 | Quine says quantified modal logic creates nonsense, bad ontology, and false essentialism [Melia on Quine] |
8789 | Various strategies try to deal with the ontological commitments of second-order logic [Hale/Wright on Quine] |
21593 | In talking of future sea-fights, Aristotle rejects bivalence [Aristotle, by Williamson] |
1701 | A prayer is a sentence which is neither true nor false [Aristotle] |
16966 | Philosophers tend to distinguish broad 'being' from narrower 'existence' - but I reject that [Quine] |
1706 | Non-existent things aren't made to exist by thought, because their non-existence is part of the thought [Aristotle] |
1707 | Maybe necessity and non-necessity are the first principles of ontology [Aristotle] |
16965 | All we have of general existence is what existential quantifiers express [Quine] |
16963 | Existence is implied by the quantifiers, not by the constants [Quine] |
16964 | Theories are committed to objects of which some of its predicates must be true [Quine] |
4216 | Express a theory in first-order predicate logic; its ontology is the types of bound variable needed for truth [Quine, by Lowe] |
18966 | Ontological commitment of theories only arise if they are classically quantified [Quine] |
14490 | You can be implicitly committed to something without quantifying over it [Thomasson on Quine] |
16961 | In formal terms, a category is the range of some style of variables [Quine] |
5038 | Assume that mind and body follow their own laws, but God has harmonised them [Leibniz] |
2337 | For Aristotle meaning and reference are linked to concepts [Aristotle, by Putnam] |
13763 | Spoken sounds vary between people, but are signs of affections of soul, which are the same for all [Aristotle] |
1705 | It doesn't have to be the case that in opposed views one is true and the other false [Aristotle] |
1702 | Things may be necessary once they occur, but not be unconditionally necessary [Aristotle] |
5037 | God doesn't decide that Adam will sin, but that sinful Adam's existence is to be preferred [Leibniz] |