91 ideas
19073 | True philosophy aims at absolute unity, while our understanding sees only separation [Hegel] |
15624 | Free thinking has no presuppositions [Hegel] |
15631 | The ideal of reason is the unification of abstract identity (or 'concept') and being [Hegel] |
15612 | Older metaphysics naively assumed that thought grasped things in themselves [Hegel] |
21768 | Logic is metaphysics, the science of things grasped in thoughts [Hegel] |
21984 | We must break up the rigidity that our understanding has imposed [Hegel] |
22081 | Let thought follow its own course, and don't interfere [Hegel] |
14779 | I reason in order to avoid disappointment and surprise [Peirce] |
15626 | Categories create objective experience, but are too conditioned by things to actually grasp them [Hegel] |
15616 | If truth is just non-contradiction, we must take care that our basic concepts aren't contradictory [Hegel] |
15638 | Dialectic is the moving soul of scientific progression, the principle which binds science together [Hegel] |
21767 | Dialectic is seen in popular proverbs like 'pride comes before a fall' [Hegel] |
15639 | Socratic dialectic is subjective, but Plato made it freely scientific and objective [Hegel] |
15615 | Older metaphysics became dogmatic, by assuming opposed assertions must be true and false [Hegel] |
9955 | Contextual definitions replace a complete sentence containing the expression [George/Velleman] |
10031 | Impredicative definitions quantify over the thing being defined [George/Velleman] |
19070 | Superficial truth is knowing how something is, which is consciousness of bare correctness [Hegel] |
5644 | In Hegel's logic it is concepts (rather than judgements or propositions) which are true or false [Hegel, by Scruton] |
19072 | In the deeper sense of truth, to be untrue resembles being bad; badness is untrue to a thing's nature [Hegel] |
19071 | The deeper sense of truth is a thing matching the idea of what it ought to be [Hegel] |
14777 | That a judgement is true and that we judge it true are quite different things [Peirce] |
10098 | The 'power set' of A is all the subsets of A [George/Velleman] |
10101 | Cartesian Product A x B: the set of all ordered pairs in which a∈A and b∈B [George/Velleman] |
10099 | The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}} [George/Velleman] |
10103 | Grouping by property is common in mathematics, usually using equivalence [George/Velleman] |
10104 | 'Equivalence' is a reflexive, symmetric and transitive relation; 'same first letter' partitions English words [George/Velleman] |
10096 | Even the elements of sets in ZFC are sets, resting on the pure empty set [George/Velleman] |
10097 | Axiom of Extensionality: for all sets x and y, if x and y have the same elements then x = y [George/Velleman] |
10100 | Axiom of Pairing: for all sets x and y, there is a set z containing just x and y [George/Velleman] |
17900 | The Axiom of Reducibility made impredicative definitions possible [George/Velleman] |
10109 | ZFC can prove that there is no set corresponding to the concept 'set' [George/Velleman] |
10108 | As a reduction of arithmetic, set theory is not fully general, and so not logical [George/Velleman] |
14780 | Only study logic if you think your own reasoning is deficient [Peirce] |
21595 | Excluded middle is the maxim of definite understanding, but just produces contradictions [Hegel] |
10111 | Asserting Excluded Middle is a hallmark of realism about the natural world [George/Velleman] |
10129 | A 'model' is a meaning-assignment which makes all the axioms true [George/Velleman] |
10105 | Differences between isomorphic structures seem unimportant [George/Velleman] |
10119 | Consistency is a purely syntactic property, unlike the semantic property of soundness [George/Velleman] |
10126 | A 'consistent' theory cannot contain both a sentence and its negation [George/Velleman] |
10120 | Soundness is a semantic property, unlike the purely syntactic property of consistency [George/Velleman] |
10127 | A 'complete' theory contains either any sentence or its negation [George/Velleman] |
15628 | The idea that contradiction is essential to rational understanding is a key modern idea [Hegel] |
15629 | Tenderness for the world solves the antinomies; contradiction is in our reason, not in the essence of the world [Hegel] |
15630 | Antinomies are not just in four objects, but in all objects, all representations, all objects and all ideas [Hegel] |
10106 | Rational numbers give answers to division problems with integers [George/Velleman] |
10102 | The integers are answers to subtraction problems involving natural numbers [George/Velleman] |
10107 | Real numbers provide answers to square root problems [George/Velleman] |
9946 | Logicists say mathematics is applicable because it is totally general [George/Velleman] |
10125 | The classical mathematician believes the real numbers form an actual set [George/Velleman] |
17899 | Second-order induction is stronger as it covers all concepts, not just first-order definable ones [George/Velleman] |
10128 | The Incompleteness proofs use arithmetic to talk about formal arithmetic [George/Velleman] |
17902 | A successor is the union of a set with its singleton [George/Velleman] |
10133 | Frege's Theorem shows the Peano Postulates can be derived from Hume's Principle [George/Velleman] |
10130 | Set theory can prove the Peano Postulates [George/Velleman] |
10089 | Talk of 'abstract entities' is more a label for the problem than a solution to it [George/Velleman] |
10131 | If mathematics is not about particulars, observing particulars must be irrelevant [George/Velleman] |
10092 | In the unramified theory of types, the types are objects, then sets of objects, sets of sets etc. [George/Velleman] |
10094 | The theory of types seems to rule out harmless sets as well as paradoxical ones. [George/Velleman] |
10095 | Type theory has only finitely many items at each level, which is a problem for mathematics [George/Velleman] |
17901 | Type theory prohibits (oddly) a set containing an individual and a set of individuals [George/Velleman] |
10114 | Bounded quantification is originally finitary, as conjunctions and disjunctions [George/Velleman] |
10134 | Much infinite mathematics can still be justified finitely [George/Velleman] |
10123 | The intuitionists are the idealists of mathematics [George/Velleman] |
10124 | Gödel's First Theorem suggests there are truths which are independent of proof [George/Velleman] |
14778 | Facts are hard unmoved things, unaffected by what people may think of them [Peirce] |
22078 | Even simple propositions about sensations are filled with categories [Hegel] |
15634 | Thought about particulars is done entirely through categories [Hegel] |
21981 | The one substance is formless without the mediation of dialectical concepts [Hegel] |
15637 | Essence is the essential self-positing unity of immediacy and mediation [Hegel] |
15613 | Real cognition grasps a thing from within itself, and is not satisfied with mere predicates [Hegel] |
15636 | The Cogito is at the very centre of the entire concern of modern philosophy [Hegel] |
22300 | Existence is just a set of relationships [Hegel] |
15609 | The sensible is distinguished from thought by being about singular things [Hegel] |
15625 | Sense perception is secondary and dependent, while thought is independent and primitive [Hegel] |
15619 | Empiricism made particular knowledge possible, and blocked wild claims [Hegel] |
15620 | Empiricism contains the important idea that we should see knowledge for ourselves, and be part of it [Hegel] |
15622 | Empiricism unknowingly contains and uses a metaphysic, which underlies its categories [Hegel] |
15621 | Empiricism of the finite denies the supersensible, and can only think with formal abstraction [Hegel] |
15632 | The Humean view stops us thinking about perception, and finding universals and necessities in it [Hegel] |
15623 | Humean scepticism, unlike ancient Greek scepticism, accepts the truth of experience as basic [Hegel] |
15617 | In abstraction, beyond finitude, freedom and necessity must exist together [Hegel] |
15608 | The act of thinking is the bringing forth of universals [Hegel] |
21986 | Hegel's system has a vast number of basic concepts [Hegel, by Moore,AW] |
15607 | We don't think with concepts - we think the concepts [Hegel] |
15610 | Active thought about objects produces the universal, which is what is true and essential of it [Hegel] |
10110 | Corresponding to every concept there is a class (some of them sets) [George/Velleman] |
15614 | Old metaphysics tried to grasp eternal truths through causal events, which is impossible [Hegel] |
15618 | If God is the abstract of Supremely Real Essence, then God is a mere Beyond, and unknowable [Hegel] |
15635 | The older conception of God was emptied of human features, to make it worthy of the Infinite [Hegel] |
21980 | God is the absolute thing, and also the absolute person [Hegel] |
15633 | We establish unification of the Ideal by the ontological proof, deriving being from abstraction of thinking [Hegel] |