22 ideas
23657 | The existence of tensed verbs shows that not all truths are necessary truths [Reid] |
23655 | An ad hominem argument is good, if it is shown that the man's principles are inconsistent [Reid] |
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] |
23659 | If someone denies that he is thinking when he is conscious of it, we can only laugh [Reid] |
23662 | The existence of ideas is no more obvious than the existence of external objects [Reid] |
23661 | We are only aware of other beings through our senses; without that, we are alone in the universe [Reid] |
23654 | In obscure matters the few must lead the many, but the many usually lead in common sense [Reid] |
23660 | The theory of ideas, popular with philosophers, means past existence has to be proved [Reid] |
23658 | Consciousness is an indefinable and unique operation [Reid] |
14802 | Physical and psychical laws of mind are either independent, or derived in one or other direction [Peirce] |
23656 | The structure of languages reveals a uniformity in basic human opinions [Reid] |
23653 | If you can't distinguish the features of a complex object, your notion of it would be a muddle [Reid] |
23663 | There are axioms of taste - such as a general consensus about a beautiful face [Reid] |
14800 | The world is full of variety, but laws seem to produce uniformity [Peirce] |
14801 | Darwinian evolution is chance, with the destruction of bad results [Peirce] |