30 ideas
10888 | Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo] |
10889 | The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo] |
10890 | A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo] |
10886 | Determinacy: an object is either in a set, or it isn't [Zalabardo] |
10887 | Specification: Determinate totals of objects always make a set [Zalabardo] |
10897 | A first-order 'sentence' is a formula with no free variables [Zalabardo] |
10893 | Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo] |
10899 | Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo] |
10896 | Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo] |
10898 | The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo] |
10902 | We can do semantics by looking at given propositions, or by building new ones [Zalabardo] |
10892 | We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo] |
10900 | Logically true sentences are true in all structures [Zalabardo] |
10895 | 'Logically true' (|= φ) is true for every truth-assignment [Zalabardo] |
10901 | Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo] |
10894 | A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo] |
10903 | A structure models a sentence if it is true in the model, and a set of sentences if they are all true in the model [Zalabardo] |
10891 | If a set is defined by induction, then proof by induction can be applied to it [Zalabardo] |
3986 | The 'intentional stance' is a way of interpreting an entity by assuming it is rational and self-aware [Dennett] |
3987 | Like the 'centre of gravity', desires and beliefs are abstract concepts with no actual existence [Dennett] |
3984 | The nature of content is entirely based on its functional role [Dennett] |
8122 | True works of art transmit completely new feelings [Tolstoy] |
8121 | Art is when one man uses external signs to hand on his feelings to another man [Tolstoy] |
8124 | The highest feelings of mankind can only be transmitted by art [Tolstoy] |
8123 | The purpose of art is to help mankind to evolve better, more socially beneficial feelings [Tolstoy] |
22710 | People estimate art according to their moral values [Tolstoy] |
8125 | The upper classes put beauty first, and thus freed themselves from morality [Tolstoy] |
8064 | We separate the concept of beauty from goodness, unlike the ancients [Tolstoy] |
3983 | Learning is evolution in the brain [Dennett] |
3985 | Biology is a type of engineering, not a search for laws of nature [Dennett] |