28 ideas
18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
20768 | Like spiderswebs, dialectical arguments are clever but useless [Ariston, by Diog. Laertius] |
9143 | Implicit definitions must be satisfiable, creative definitions introduce things, contextual definitions build on things [Fine,K, by Cook/Ebert] |
10143 | 'Creative definitions' do not presuppose the existence of the objects defined [Fine,K] |
18789 | Intuitionist logic looks best as natural deduction [Mares] |
18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
18782 | The connectives are studied either through model theory or through proof theory [Mares] |
18783 | Many-valued logics lack a natural deduction system [Mares] |
18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
10145 | Abstracts cannot be identified with sets [Fine,K] |
10136 | Points in Euclidean space are abstract objects, but not introduced by abstraction [Fine,K] |
10144 | Postulationism says avoid abstract objects by giving procedures that produce truth [Fine,K] |
9144 | Fine's 'procedural postulationism' uses creative definitions, but avoids abstract ontology [Fine,K, by Cook/Ebert] |
10141 | Many different kinds of mathematical objects can be regarded as forms of abstraction [Fine,K] |
10135 | We can abstract from concepts (e.g. to number) and from objects (e.g. to direction) [Fine,K] |
9142 | Fine considers abstraction as reconceptualization, to produce new senses by analysing given senses [Fine,K, by Cook/Ebert] |
10137 | Abstractionism can be regarded as an alternative to set theory [Fine,K] |
10138 | An object is the abstract of a concept with respect to a relation on concepts [Fine,K] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
3049 | The chief good is indifference to what lies midway between virtue and vice [Ariston, by Diog. Laertius] |
3549 | Ariston says rules are useless for the virtuous and the non-virtuous [Ariston, by Annas] |