75 ideas
8721 | An 'impredicative' definition seems circular, because it uses the term being defined [Friend] |
8680 | Classical definitions attempt to refer, but intuitionist/constructivist definitions actually create objects [Friend] |
3678 | Reductio ad absurdum proves an idea by showing that its denial produces contradiction [Friend] |
8187 | Frege was strongly in favour of taking truth to attach to propositions [Frege, by Dummett] |
8705 | Anti-realists see truth as our servant, and epistemically contrained [Friend] |
8713 | In classical/realist logic the connectives are defined by truth-tables [Friend] |
8708 | Double negation elimination is not valid in intuitionist logic [Friend] |
8694 | Free logic was developed for fictional or non-existent objects [Friend] |
8665 | A 'proper subset' of A contains only members of A, but not all of them [Friend] |
8672 | A 'powerset' is all the subsets of a set [Friend] |
8677 | Set theory makes a minimum ontological claim, that the empty set exists [Friend] |
8666 | Infinite sets correspond one-to-one with a subset [Friend] |
8682 | Major set theories differ in their axioms, and also over the additional axioms of choice and infinity [Friend] |
8709 | The law of excluded middle is syntactic; it just says A or not-A, not whether they are true or false [Friend] |
18772 | We can treat designation by a few words as a proper name [Frege] |
14075 | Proper name in modal contexts refer obliquely, to their usual sense [Frege, by Gibbard] |
10424 | A Fregean proper name has a sense determining an object, instead of a concept [Frege, by Sainsbury] |
18773 | People may have different senses for 'Aristotle', like 'pupil of Plato' or 'teacher of Alexander' [Frege] |
4978 | The meaning of a proper name is the designated object [Frege] |
10510 | Frege ascribes reference to incomplete expressions, as well as to singular terms [Frege, by Hale] |
18937 | If sentences have a 'sense', empty name sentences can be understood that way [Frege, by Sawyer] |
18940 | It is a weakness of natural languages to contain non-denoting names [Frege] |
18939 | In a logically perfect language every well-formed proper name designates an object [Frege] |
8711 | Intuitionists read the universal quantifier as "we have a procedure for checking every..." [Friend] |
9462 | Frege is intensionalist about reference, as it is determined by sense; identity of objects comes first [Frege, by Jacquette] |
18936 | Frege moved from extensional to intensional semantics when he added the idea of 'sense' [Frege, by Sawyer] |
8675 | Paradoxes can be solved by talking more loosely of 'classes' instead of 'sets' [Friend] |
8674 | The Burali-Forti paradox asks whether the set of all ordinals is itself an ordinal [Friend] |
8667 | The 'integers' are the positive and negative natural numbers, plus zero [Friend] |
8668 | The 'rational' numbers are those representable as fractions [Friend] |
8670 | A number is 'irrational' if it cannot be represented as a fraction [Friend] |
8661 | The natural numbers are primitive, and the ordinals are up one level of abstraction [Friend] |
8664 | Cardinal numbers answer 'how many?', with the order being irrelevant [Friend] |
8671 | The 'real' numbers (rationals and irrationals combined) is the Continuum, which has no gaps [Friend] |
8663 | Raising omega to successive powers of omega reveal an infinity of infinities [Friend] |
8662 | The first limit ordinal is omega (greater, but without predecessor), and the second is twice-omega [Friend] |
8669 | Between any two rational numbers there is an infinite number of rational numbers [Friend] |
8676 | Is mathematics based on sets, types, categories, models or topology? [Friend] |
8678 | Most mathematical theories can be translated into the language of set theory [Friend] |
8701 | The number 8 in isolation from the other numbers is of no interest [Friend] |
8702 | In structuralism the number 8 is not quite the same in different structures, only equivalent [Friend] |
8699 | Are structures 'ante rem' (before reality), or are they 'in re' (grounded in physics)? [Friend] |
8696 | Structuralist says maths concerns concepts about base objects, not base objects themselves [Friend] |
8695 | Structuralism focuses on relations, predicates and functions, with objects being inessential [Friend] |
8700 | 'In re' structuralism says that the process of abstraction is pattern-spotting [Friend] |
8681 | The big problem for platonists is epistemic: how do we perceive, intuit, know or detect mathematical facts? [Friend] |
8712 | Mathematics should be treated as true whenever it is indispensable to our best physical theory [Friend] |
8716 | Formalism is unconstrained, so cannot indicate importance, or directions for research [Friend] |
8706 | Constructivism rejects too much mathematics [Friend] |
8707 | Intuitionists typically retain bivalence but reject the law of excluded middle [Friend] |
10533 | We can't get a semantics from nouns and predicates referring to the same thing [Frege, by Dummett] |
8704 | Structuralists call a mathematical 'object' simply a 'place in a structure' [Friend] |
4893 | Frege was asking how identities could be informative [Frege, by Perry] |
8685 | Studying biology presumes the laws of chemistry, and it could never contradict them [Friend] |
8688 | Concepts can be presented extensionally (as objects) or intensionally (as a characterization) [Friend] |
18752 | 'The concept "horse"' denotes a concept, yet seems also to denote an object [Frege, by McGee] |
22318 | Frege failed to show when two sets of truth-conditions are equivalent [Frege, by Potter] |
4980 | The meaning (reference) of a sentence is its truth value - the circumstance of it being true or false [Frege] |
9180 | Holism says all language use is also a change in the rules of language [Frege, by Dummett] |
4981 | The reference of a word should be understood as part of the reference of the sentence [Frege] |
15597 | Frege's Puzzle: from different semantics we infer different reference for two names with the same reference [Frege, by Fine,K] |
17002 | Frege's 'sense' is ambiguous, between the meaning of a designator, and how it fixes reference [Kripke on Frege] |
18778 | Every descriptive name has a sense, but may not have a reference [Frege] |
7805 | Frege started as anti-realist, but the sense/reference distinction led him to realism [Frege, by Benardete,JA] |
4976 | The meaning (reference) of 'evening star' is the same as that of 'morning star', but not the sense [Frege] |
4977 | In maths, there are phrases with a clear sense, but no actual reference [Frege] |
4979 | We are driven from sense to reference by our desire for truth [Frege] |
15155 | Expressions always give ways of thinking of referents, rather than the referents themselves [Frege, by Soames] |
11126 | 'Sense' gives meaning to non-referring names, and to two expressions for one referent [Frege, by Margolis/Laurence] |
8164 | Frege was the first to construct a plausible theory of meaning [Frege, by Dummett] |
9817 | Earlier Frege focuses on content itself; later he became interested in understanding content [Frege, by Dummett] |
8171 | Frege divided the meaning of a sentence into sense, force and tone [Frege, by Dummett] |
4954 | Frege uses 'sense' to mean both a designator's meaning, and the way its reference is determined [Kripke on Frege] |
7304 | Frege explained meaning as sense, semantic value, reference, force and tone [Frege, by Miller,A] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |