94 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] |
| 17926 | Rejecting double negation elimination undermines reductio proofs [Colyvan] |
| 17925 | Showing a disproof is impossible is not a proof, so don't eliminate double negation [Colyvan] |
| 17924 | Excluded middle says P or not-P; bivalence says P is either true or false [Colyvan] |
| 17929 | Löwenheim proved his result for a first-order sentence, and Skolem generalised it [Colyvan] |
| 17930 | Axioms are 'categorical' if all of their models are isomorphic [Colyvan] |
| 17928 | Ordinal numbers represent order relations [Colyvan] |
| 17923 | Intuitionists only accept a few safe infinities [Colyvan] |
| 17941 | Infinitesimals were sometimes zero, and sometimes close to zero [Colyvan] |
| 17922 | Reducing real numbers to rationals suggested arithmetic as the foundation of maths [Colyvan] |
| 17936 | Transfinite induction moves from all cases, up to the limit ordinal [Colyvan] |
| 17940 | Most mathematical proofs are using set theory, but without saying so [Colyvan] |
| 17931 | Structuralism say only 'up to isomorphism' matters because that is all there is to it [Colyvan] |
| 17932 | If 'in re' structures relies on the world, does the world contain rich enough structures? [Colyvan] |
| 23634 | Accepting the existence of anything presupposes the notion of existence [Reid] |
| 23664 | Powers are quite distinct and simple, and so cannot be defined [Reid] |
| 23669 | Thinkers say that matter has intrinsic powers, but is also passive and acted upon [Reid] |
| 23666 | It is obvious that there could not be a power without a subject which possesses it [Reid] |
| 23651 | Universals are not objects of sense and cannot be imagined - but can be conceived [Reid] |
| 23650 | Only individuals exist [Reid] |
| 23649 | No one thinks two sheets possess a single whiteness, but all agree they are both white [Reid] |
| 23647 | Objects have an essential constitution, producing its qualities, which we are too ignorant to define [Reid] |
| 1350 | Continuity is needed for existence, otherwise we would say a thing existed after it ceased to exist [Reid] |
| 21322 | We treat slowly changing things as identical for the sake of economy in language [Reid] |
| 21320 | Identity is familiar to common sense, but very hard to define [Reid] |
| 1367 | Identity can only be affirmed of things which have a continued existence [Reid] |
| 11874 | Real identity admits of no degrees [Reid] |
| 11958 | Impossibilites are easily conceived in mathematics and geometry [Reid, by Molnar] |
| 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] |
| 23635 | Truths are self-evident to sensible persons who understand them clearly without prejudice [Reid] |
| 7631 | Sensation is not committed to any external object, but perception is [Reid] |
| 23637 | Primary qualities are the object of mathematics [Reid] |
| 23638 | Secondary qualities conjure up, and are confused with, the sensations which produce them [Reid] |
| 23639 | It is unclear whether a toothache is in the mind or in the tooth, but the word has a single meaning [Reid] |
| 6492 | Reid is seen as the main direct realist of the eighteenth century [Reid, by Robinson,H] |
| 23633 | Many truths seem obvious, and point to universal agreement - which is what we find [Reid] |
| 23654 | In obscure matters the few must lead the many, but the many usually lead in common sense [Reid] |
| 23644 | Without memory we could have no concept of duration [Reid] |
| 23643 | We all trust our distinct memories (but not our distinct imaginings) [Reid] |
| 23660 | The theory of ideas, popular with philosophers, means past existence has to be proved [Reid] |
| 23641 | People dislike believing without evidence, and try to avoid it [Reid] |
| 23642 | If non-rational evidence reaches us, it is reason which then makes use of it [Reid] |
| 23549 | We treat testimony with a natural trade off of belief and caution [Reid, by Fricker,M] |
| 3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
| 17943 | Probability supports Bayesianism better as degrees of belief than as ratios of frequencies [Colyvan] |
| 17939 | Mathematics can reveal structural similarities in diverse systems [Colyvan] |
| 17938 | Mathematics can show why some surprising events have to occur [Colyvan] |
| 17934 | Proof by cases (by 'exhaustion') is said to be unexplanatory [Colyvan] |
| 17933 | Reductio proofs do not seem to be very explanatory [Colyvan] |
| 17935 | If inductive proofs hold because of the structure of natural numbers, they may explain theorems [Colyvan] |
| 17942 | Can a proof that no one understands (of the four-colour theorem) really be a proof? [Colyvan] |
| 1356 | A person is a unity, and doesn't come in degrees [Reid] |
| 23658 | Consciousness is an indefinable and unique operation [Reid] |
| 23665 | Consciousness is the power of mind to know itself, and minds are grounded in powers [Reid] |
| 17937 | Mathematical generalisation is by extending a system, or by abstracting away from it [Colyvan] |
| 1359 | Personal identity is the basis of all rights, obligations and responsibility [Reid] |
| 21319 | I can hardly care about rational consequence if it wasn't me conceiving the antecedent [Reid] |
| 21323 | The identity of a thief is only known by similarity, but memory gives certainty in our own case [Reid] |
| 21321 | Memory reveals my past identity - but so does testimony of other witnesses [Reid] |
| 21324 | If consciousness is transferable 20 persons can be 1; forgetting implies 1 can be 20 [Reid] |
| 21325 | Boy same as young man, young man same as old man, old man not boy, if forgotten! [Reid] |
| 21327 | If a stolen horse is identified by similitude, its identity is not therefore merely similitude [Reid] |
| 1366 | If consciousness is personal identity, it is continually changing [Reid] |
| 1352 | Thoughts change continually, but the self doesn't [Reid] |
| 23681 | The first motion or effect cannot be produced necessarily, so the First Cause must be a free agent [Reid] |
| 23676 | A willed action needs reasonable understanding of what is to be done [Reid] |
| 23668 | Our own nature attributes free determinations to our own will [Reid] |
| 23680 | We are morally free, because we experience it, we are accountable, and we pursue projects [Reid] |
| 23652 | We must first conceive things before we can consider them [Reid] |
| 23656 | The structure of languages reveals a uniformity in basic human opinions [Reid] |
| 23630 | Only philosophers treat ideas as objects [Reid] |
| 23648 | First we notice and name attributes ('abstracting'); then we notice that subjects share them ('generalising') [Reid] |
| 23653 | If you can't distinguish the features of a complex object, your notion of it would be a muddle [Reid] |
| 23640 | Only mature minds can distinguish the qualities of a body [Reid] |
| 23629 | The ambiguity of words impedes the advancement of knowledge [Reid] |
| 23646 | Reference is by name, or a term-plus-circumstance, or ostensively, or by description [Reid] |
| 23645 | A word's meaning is the thing conceived, as fixed by linguistic experts [Reid] |
| 20051 | Reid said that agent causation is a unique type of causation [Reid, by Stout,R] |
| 23678 | A motive is merely an idea, like advice, and not a force for action [Reid] |
| 23663 | There are axioms of taste - such as a general consensus about a beautiful face [Reid] |
| 23674 | If an attempted poisoning results in benefits, we still judge the agent a poisoner [Reid] |
| 23675 | We shouldn't do to others what would be a wrong to us in similar circumstances [Reid] |
| 23672 | To be virtuous, we must care about duty [Reid] |
| 23673 | Every worthy man has a principle of honour, and knows what is honourable [Reid] |
| 23632 | Similar effects come from similar causes, and causes are only what are sufficient for the effects [Reid] |
| 8383 | Day and night are constantly conjoined, but they don't cause one another [Reid, by Crane] |
| 23677 | We all know that mere priority or constant conjunction do not have to imply causation [Reid] |
| 23667 | Regular events don't imply a cause, without an innate conviction of universal causation [Reid] |
| 23679 | The principle of the law of nature is that matter is passive, and is acted upon [Reid] |
| 23670 | Scientists don't know the cause of magnetism, and only discover its regulations [Reid] |
| 23671 | Laws are rules for effects, but these need a cause; rules of navigation don't navigate [Reid] |