74 ideas
5728 | The concept of truth was originated by the senses [Lucretius] |
13252 | Some truths have true negations [Beall/Restall] |
13247 | A truthmaker is an object which entails a sentence [Beall/Restall] |
10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
13249 | (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall] |
13243 | Excluded middle must be true for some situation, not for all situations [Beall/Restall] |
13242 | It's 'relevantly' valid if all those situations make it true [Beall/Restall] |
13246 | Relevant logic does not abandon classical logic [Beall/Restall] |
13245 | Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall] |
13254 | A doesn't imply A - that would be circular [Beall/Restall] |
13255 | Relevant logic may reject transitivity [Beall/Restall] |
13250 | Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall] |
13235 | Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall] |
13238 | Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall] |
13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |
10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
13232 | Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall] |
13241 | The model theory of classical predicate logic is mathematics [Beall/Restall] |
10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
13253 | There are several different consequence relations [Beall/Restall] |
13240 | A sentence follows from others if they always model it [Beall/Restall] |
10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
13236 | Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall] |
10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
13237 | Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall] |
10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
5702 | The senses are much the best way to distinguish true from false [Lucretius] |
5729 | If the senses are deceptive, reason, which rests on them, is even worse [Lucretius] |
5697 | The only possible standard for settling doubts is the foundation of the senses [Lucretius] |
5727 | Most supposed delusions of the senses are really misinterpretations by the mind [Lucretius] |
5714 | Even simple facts are hard to believe at first hearing [Lucretius] |
5718 | The mind is in the middle of the breast, because there we experience fear and joy [Lucretius] |
5717 | The mind is a part of a man, just like a hand or an eye [Lucretius] |
21387 | The separate elements and capacities of a mind cannot be distinguished [Lucretius] |
5709 | The actions of the mind are not determinate and passive, because atoms can swerve [Lucretius] |
5695 | Only bodies can touch one another [Lucretius] |
5711 | The earth is and always has been an insentient being [Lucretius] |
5712 | Particles may have sensation, but eggs turning into chicks suggests otherwise [Lucretius] |
5719 | The mind moves limbs, wakes the body up, changes facial expressions, which involve touch [Lucretius] |
5724 | Lions, foxes and deer have distinct characters because their minds share in their bodies [Lucretius] |
5713 | You needn't be made of laughing particles to laugh, so why not sensation from senseless seeds? [Lucretius] |
13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
13248 | We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall] |
13233 | Propositions commit to content, and not to any way of spelling it out [Beall/Restall] |
6611 | One man's meat is another man's poison [Lucretius] |
5730 | Our bodies weren't created to be used; on the contrary, their creation makes a use possible [Lucretius] |
5726 | The dead are no different from those who were never born [Lucretius] |
5705 | Nature only wants two things: freedom from pain, and pleasure [Lucretius] |
6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
5716 | Nature runs the universe by herself without the aid of gods [Lucretius] |
5704 | There can be no centre in infinity [Lucretius] |
5703 | The universe must be limitless, since there could be nothing outside to limit it [Lucretius] |
5693 | Everything is created and fed by nature from atoms, and they return to atoms in death [Lucretius] |
5701 | If an object is infinitely subdivisible, it will be the same as the whole universe [Lucretius] |
5708 | In downward motion, atoms occasionally swerve slightly for no reason [Lucretius] |
17004 | Nothing can break the binding laws of eternity [Lucretius] |
5696 | If there were no space there could be no movement, or even creation [Lucretius] |
5706 | Atoms move themselves [Lucretius] |
5700 | It is quicker to break things up than to assemble them [Lucretius] |
5698 | We can only sense time by means of movement, or its absence [Lucretius] |
5715 | This earth is very unlikely to be the only one created [Lucretius] |
5694 | Nothing can be created by divine power out of nothing [Lucretius] |
5699 | If matter wasn't everlasting, everything would have disappeared by now [Lucretius] |
5707 | The universe can't have been created by gods, because it is too imperfect [Lucretius] |
5710 | Gods are tranquil and aloof, and have no need of or interest in us [Lucretius] |
5731 | Why does Jupiter never hurl lightning from a blue sky? [Lucretius] |
5722 | For a separated spirit to remain sentient it would need sense organs attached to it [Lucretius] |
5725 | An immortal mind couldn't work harmoniously with a mortal body [Lucretius] |
5720 | Spirit is mortal [Lucretius] |
5721 | The mind is very small smooth particles, which evaporate at death [Lucretius] |
5723 | If spirit is immortal and enters us at birth, why don't we remember a previous existence? [Lucretius] |