22 ideas
7740 | There exists a realm, beyond objects and ideas, of non-spatio-temporal thoughts [Frege, by Weiner] |
19466 | The word 'true' seems to be unique and indefinable [Frege] |
19465 | There cannot be complete correspondence, because ideas and reality are quite different [Frege] |
19468 | The property of truth in 'It is true that I smell violets' adds nothing to 'I smell violets' [Frege] |
13913 | The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward] |
13914 | Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts [Engelbretsen/Sayward] |
13915 | Syllogistic can't handle sentences with singular terms, or relational terms, or compound sentences [Engelbretsen/Sayward] |
13916 | Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward] |
13850 | In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward] |
13849 | Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward] |
13851 | Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward] |
13852 | Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward] |
19470 | Thoughts in the 'third realm' cannot be sensed, and do not need an owner to exist [Frege] |
19471 | A fact is a thought that is true [Frege] |
9877 | Late Frege saw his non-actual objective objects as exclusively thoughts and senses [Frege, by Dummett] |
1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
19469 | We grasp thoughts (thinking), decide they are true (judgement), and manifest the judgement (assertion) [Frege] |
8162 | Thoughts have their own realm of reality - 'sense' (as opposed to the realm of 'reference') [Frege, by Dummett] |
9818 | A thought is distinguished from other things by a capacity to be true or false [Frege, by Dummett] |
16379 | Thoughts about myself are understood one way to me, and another when communicated [Frege] |
19467 | A 'thought' is something for which the question of truth can arise; thoughts are senses of sentences [Frege] |
19472 | A sentence is only a thought if it is complete, and has a time-specification [Frege] |