96 ideas
| 19579 | The history of philosophy is just experiments in how to do philosophy [Novalis] |
| 19583 | Philosophy only begins when it studies itself [Novalis] |
| 22026 | Philosophy is homesickness - the urge to be at home everywhere [Novalis] |
| 19588 | The highest aim of philosophy is to combine all philosophies into a unity [Novalis] |
| 19598 | Philosophy relies on our whole system of learning, and can thus never be complete [Novalis] |
| 19586 | Philosophers feed on problems, hoping they are digestible, and spiced with paradox [Novalis] |
| 19587 | Philosophy aims to produce a priori an absolute and artistic world system [Novalis] |
| 22285 | Impredicative definitions are circular, but fine for picking out, rather than creating something [Potter] |
| 22301 | The Identity Theory says a proposition is true if it coincides with what makes it true [Potter] |
| 19574 | If man sacrifices truth he sacrifices himself, by acting against his own convictions [Novalis] |
| 22324 | It has been unfortunate that externalism about truth is equated with correspondence [Potter] |
| 19571 | Delusion and truth differ in their life functions [Novalis] |
| 15945 | Second-order set theory just adds a version of Replacement that quantifies over functions [Lavine] |
| 10702 | Set theory's three roles: taming the infinite, subject-matter of mathematics, and modes of reasoning [Potter] |
| 15914 | An 'upper bound' is the greatest member of a subset; there may be several of these, so there is a 'least' one [Lavine] |
| 15921 | Collections of things can't be too big, but collections by a rule seem unlimited in size [Lavine] |
| 10713 | Usually the only reason given for accepting the empty set is convenience [Potter] |
| 15937 | Those who reject infinite collections also want to reject the Axiom of Choice [Lavine] |
| 13044 | Infinity: There is at least one limit level [Potter] |
| 15936 | The Power Set is just the collection of functions from one collection to another [Lavine] |
| 15899 | Replacement was immediately accepted, despite having very few implications [Lavine] |
| 15930 | Foundation says descending chains are of finite length, blocking circularity, or ungrounded sets [Lavine] |
| 15920 | Pure collections of things obey Choice, but collections defined by a rule may not [Lavine] |
| 15898 | The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules [Lavine] |
| 15919 | The 'logical' notion of class has some kind of definition or rule to characterise the class [Lavine] |
| 15900 | The iterative conception of set wasn't suggested until 1947 [Lavine] |
| 10708 | Nowadays we derive our conception of collections from the dependence between them [Potter] |
| 15931 | The iterative conception needs the Axiom of Infinity, to show how far we can iterate [Lavine] |
| 15932 | The iterative conception doesn't unify the axioms, and has had little impact on mathematical proofs [Lavine] |
| 13546 | The 'limitation of size' principles say whether properties collectivise depends on the number of objects [Potter] |
| 15933 | Limitation of Size: if it's the same size as a set, it's a set; it uses Replacement [Lavine] |
| 15913 | A collection is 'well-ordered' if there is a least element, and all of its successors can be identified [Lavine] |
| 10707 | Mereology elides the distinction between the cards in a pack and the suits [Potter] |
| 10704 | We can formalize second-order formation rules, but not inference rules [Potter] |
| 15926 | Second-order logic presupposes a set of relations already fixed by the first-order domain [Lavine] |
| 19597 | Logic (the theory of relations) should be applied to mathematics [Novalis] |
| 22279 | Frege's sign |--- meant judgements, but the modern |- turnstile means inference, with intecedents [Potter] |
| 22291 | Deductivism can't explain how the world supports unconditional conclusions [Potter] |
| 15934 | Mathematical proof by contradiction needs the law of excluded middle [Lavine] |
| 10703 | Supposing axioms (rather than accepting them) give truths, but they are conditional [Potter] |
| 22295 | Modern logical truths are true under all interpretations of the non-logical words [Potter] |
| 19581 | A problem is a solid mass, which the mind must break up [Novalis] |
| 15907 | Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity [Lavine] |
| 15942 | Every rational number, unlike every natural number, is divisible by some other number [Lavine] |
| 15922 | For the real numbers to form a set, we need the Continuum Hypothesis to be true [Lavine] |
| 18250 | Cauchy gave a necessary condition for the convergence of a sequence [Lavine] |
| 15904 | The two sides of the Cut are, roughly, the bounding commensurable ratios [Lavine] |
| 19584 | Whoever first counted to two must have seen the possibility of infinite counting [Novalis] |
| 10712 | If set theory didn't found mathematics, it is still needed to count infinite sets [Potter] |
| 15912 | Counting results in well-ordering, and well-ordering makes counting possible [Lavine] |
| 15949 | The theory of infinity must rest on our inability to distinguish between very large sizes [Lavine] |
| 15947 | The infinite is extrapolation from the experience of indefinitely large size [Lavine] |
| 15940 | The intuitionist endorses only the potential infinite [Lavine] |
| 15909 | 'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal [Lavine] |
| 15915 | Ordinals are basic to Cantor's transfinite, to count the sets [Lavine] |
| 15917 | Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal [Lavine] |
| 15918 | Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine] |
| 17882 | It is remarkable that all natural number arithmetic derives from just the Peano Axioms [Potter] |
| 15929 | Set theory will found all of mathematics - except for the notion of proof [Lavine] |
| 15935 | Modern mathematics works up to isomorphism, and doesn't care what things 'really are' [Lavine] |
| 22310 | The formalist defence against Gödel is to reject his metalinguistic concept of truth [Potter] |
| 22298 | Why is fictional arithmetic applicable to the real world? [Potter] |
| 15928 | Intuitionism rejects set-theory to found mathematics [Lavine] |
| 22025 | Novalis thought self-consciousness cannot disclose 'being', because we are temporal creatures [Novalis, by Pinkard] |
| 22287 | If 'concrete' is the negative of 'abstract', that means desires and hallucinations are concrete [Potter] |
| 13043 | A relation is a set consisting entirely of ordered pairs [Potter] |
| 22284 | 'Greater than', which is the ancestral of 'successor', strictly orders the natural numbers [Potter] |
| 13042 | If dependence is well-founded, with no infinite backward chains, this implies substances [Potter] |
| 13041 | Collections have fixed members, but fusions can be carved in innumerable ways [Potter] |
| 19575 | Refinement of senses increasingly distinguishes individuals [Novalis] |
| 10709 | Priority is a modality, arising from collections and members [Potter] |
| 22281 | A material conditional cannot capture counterfactual reasoning [Potter] |
| 22067 | Poetry is true idealism, and the self-consciousness of the universe [Novalis] |
| 19572 | Experiences tests reason, and reason tests experience [Novalis] |
| 19590 | Empiricists are passive thinkers, given their philosophy by the external world and fate [Novalis] |
| 22327 | Knowledge from a drunken schoolteacher is from a reliable and unreliable process [Potter] |
| 19594 | General statements about nature are not valid [Novalis] |
| 19591 | Desire for perfection is an illness, if it turns against what is imperfect [Novalis] |
| 19596 | The whole body is involved in the formation of thoughts [Novalis] |
| 19573 | The seat of the soul is where our inner and outer worlds interpenetrate [Novalis] |
| 22273 | Traditionally there are twelve categories of judgement, in groups of three [Potter] |
| 22290 | The phrase 'the concept "horse"' can't refer to a concept, because it is saturated [Potter] |
| 19577 | Everything is a chaotic unity, then we abstract, then we reunify the world into a free alliance [Novalis] |
| 22283 | Compositionality should rely on the parsing tree, which may contain more than sentence components [Potter] |
| 22282 | 'Direct compositonality' says the components wholly explain a sentence meaning [Potter] |
| 22296 | Compositionality is more welcome in logic than in linguistics (which is more contextual) [Potter] |
| 19585 | Every person has his own language [Novalis] |
| 19578 | Only self-illuminated perfect individuals are beautiful [Novalis] |
| 19582 | Morality and philosophy are mutually dependent [Novalis] |
| 22027 | Life isn't given to us like a novel - we write the novel [Novalis] |
| 19589 | The whole point of a monarch is that we accept them as a higher-born, ideal person [Novalis] |
| 19580 | If the pupil really yearns for the truth, they only need a hint [Novalis] |
| 19593 | Persons are shaped by a life history; splendid persons are shaped by world history [Novalis] |
| 19595 | Nature is a whole, and its individual parts cannot be wholly understood [Novalis] |
| 19592 | The basic relations of nature are musical [Novalis] |
| 19576 | Religion needs an intermediary, because none of us can connect directly to a godhead [Novalis] |