39 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] |
10895 | 'Logically true' (|= φ) is true for every truth-assignment [Zalabardo] |
10900 | Logically true sentences are true in all structures [Zalabardo] |
10894 | A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo] |
10901 | Some formulas are 'satisfiable' if there is a structure and interpretation that makes them 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] |
4913 | Brain lesions can erase whole categories of perception, suggesting they are hard-wired [Carter,R] |
4910 | Sense organs don't discriminate; they reduce various inputs to the same electrical pulses [Carter,R] |
4911 | The recognition sequence is: classify, name, locate, associate, feel [Carter,R, by PG] |
4919 | There seems to be no dividing line between a memory and a thought [Carter,R] |
4908 | No one knows if animals are conscious [Carter,R] |
4902 | Pain doesn't have one brain location, but is linked to attention and emotion [Carter,R] |
4904 | Proper brains appear at seven weeks, and neonates have as many neurons as adults do [Carter,R] |
4915 | In primates, brain size correlates closely with size of social group [Carter,R] |
4917 | Consciousness involves awareness, perception, self-awareness, attention and reflection [Carter,R] |
4916 | There is enormous evidence that consciousness arises in the frontal lobes of the brain [Carter,R] |
4905 | Normal babies seem to have overlapping sense experiences [Carter,R] |
4918 | In blindsight V1 (normal vision) is inactive, but V5 (movement) lights up [Carter,R] |
4912 | Out-of-body experiences may be due to temporary loss of proprioception [Carter,R] |
4903 | Scans of brains doing similar tasks produce very similar patterns of activation [Carter,R] |
4920 | Thinking takes place on the upper side of the prefrontal cortex [Carter,R] |
4906 | Babies show highly emotional brain events, but may well be unaware of them [Carter,R] |
4909 | The only way we can control our emotions is by manipulating the outside world that influences them [Carter,R] |
4914 | A frog will starve to death surrounded by dead flies [Carter,R] |
4907 | The 'locus coeruleus' is one of several candidates for the brain's 'pleasure centre' [Carter,R] |
22745 | Pherecydes said the first principle and element is earth [Pherecydes, by Sext.Empiricus] |
5883 | Pherecydes was the first to say that the soul is eternal [Pherecydes, by Cicero] |