96 ideas
22270 | Frege changed philosophy by extending logic's ability to check the grounds of thinking [Potter on Frege] |
11283 | There is pure deductive reasoning, and explanatory demonstration reasoning [Aristotle, by Politis] |
1672 | Maybe everything could be demonstrated, if demonstration can be reciprocal or circular [Aristotle] |
8939 | We should not describe human laws of thought, but how to correctly track truth [Frege, by Fisher] |
1684 | Two falsehoods can be contrary to one another [Aristotle] |
12145 | Definitions are of what something is, and that is universal [Aristotle] |
12384 | Definition by division needs predicates, which are well ordered and thorough [Aristotle] |
12075 | An Aristotelian definition is causal [Aristotle, by Witt] |
9066 | You can define objects by progressively identifying what is the same and what is different [Aristotle] |
12382 | What it is and why it is are the same; screening defines and explains an eclipse [Aristotle] |
1668 | An axiom is a principle which must be understood if one is to learn anything [Aristotle] |
4971 | I don't use 'subject' and 'predicate' in my way of representing a judgement [Frege] |
17745 | For Frege, 'All A's are B's' means that the concept A implies the concept B [Frege, by Walicki] |
7728 | Frege has a judgement stroke (vertical, asserting or judging) and a content stroke (horizontal, expressing) [Frege, by Weiner] |
16881 | The laws of logic are boundless, so we want the few whose power contains the others [Frege] |
7622 | In 1879 Frege developed second order logic [Frege, by Putnam] |
12376 | Demonstrations by reductio assume excluded middle [Aristotle] |
12373 | Something holds universally when it is proved of an arbitrary and primitive case [Aristotle] |
12363 | Everything is either asserted or denied truly [Aristotle] |
7729 | Frege replaced Aristotle's subject/predicate form with function/argument form [Frege, by Weiner] |
9950 | A quantifier is a second-level predicate (which explains how it contributes to truth-conditions) [Frege, by George/Velleman] |
9991 | For Frege the variable ranges over all objects [Frege, by Tait] |
10536 | Frege's domain for variables is all objects, but modern interpretations first fix the domain [Dummett on Frege] |
7730 | Frege introduced quantifiers for generality [Frege, by Weiner] |
7742 | Frege reduced most quantifiers to 'everything' combined with 'not' [Frege, by McCullogh] |
13824 | Proof theory began with Frege's definition of derivability [Frege, by Prawitz] |
13609 | Frege produced axioms for logic, though that does not now seem the natural basis for logic [Frege, by Kaplan] |
13004 | Aristotle's axioms (unlike Euclid's) are assumptions awaiting proof [Aristotle, by Leibniz] |
12377 | Mathematics is concerned with forms, not with superficial properties [Aristotle] |
12372 | The essence of a triangle comes from the line, mentioned in any account of triangles [Aristotle] |
12369 | A unit is what is quantitatively indivisible [Aristotle] |
17855 | It may be possible to define induction in terms of the ancestral relation [Frege, by Wright,C] |
10607 | Frege's logic has a hierarchy of object, property, property-of-property etc. [Frege, by Smith,P] |
11008 | Existence is not a first-order property, but the instantiation of a property [Frege, by Read] |
18910 | To seek truth, study the real connections between subjects and attributes [Aristotle] |
1675 | Separate Forms aren't needed for logic, but universals (one holding of many) are essential [Aristotle] |
1677 | We can forget the Forms, as they are irrelevant, and not needed in giving demonstrations [Aristotle] |
1687 | Why are being terrestrial and a biped combined in the definition of man, but being literate and musical aren't? [Aristotle] |
1681 | Units are positionless substances, and points are substances with position [Aristotle] |
12146 | Definitions recognise essences, so are not themselves essences [Aristotle] |
17039 | The predicates of a thing's nature are necessary to it [Aristotle] |
11994 | Aristotelian essences are properties mentioned at the starting point of a science [Aristotle, by Kung] |
12381 | What is necessary cannot be otherwise [Aristotle] |
1690 | A stone travels upwards by a forced necessity, and downwards by natural necessity [Aristotle] |
12072 | For Aristotle knowledge is explanatory, involving understanding, and principles or causes [Aristotle, by Witt] |
12073 | 'Episteme' means grasping causes, universal judgments, explanation, and teaching [Aristotle, by Witt] |
12378 | The reason why is the key to knowledge [Aristotle] |
12364 | We understand a thing when we know its explanation and its necessity [Aristotle] |
12370 | Some understanding, of immediate items, is indemonstrable [Aristotle] |
12366 | We only understand something when we know its explanation [Aristotle] |
1685 | No one has mere belief about something if they think it HAS to be true [Aristotle] |
1673 | Knowledge proceeds from principles, so it is hard to know if we know [Aristotle] |
19553 | Commitment to 'I have a hand' only makes sense in a context where it has been doubted [Hawthorne] |
12379 | You cannot understand anything through perception [Aristotle] |
16725 | Some knowledge is lost if you lose a sense, and there is no way the knowledge can be replaced [Aristotle] |
1693 | Animals may have some knowledge if they retain perception, but understanding requires reasons to be given [Aristotle] |
23309 | Aristotle's concepts of understanding and explanation mean he is not a pure empiricist [Aristotle, by Frede,M] |
9067 | Many memories of the same item form a single experience [Aristotle] |
1671 | Sceptics say justification is an infinite regress, or it stops at the unknowable [Aristotle] |
19551 | How can we know the heavyweight implications of normal knowledge? Must we distort 'knowledge'? [Hawthorne] |
19552 | We wouldn't know the logical implications of our knowledge if small risks added up to big risks [Hawthorne] |
19554 | Denying closure is denying we know P when we know P and Q, which is absurd in simple cases [Hawthorne] |
1670 | When you understand basics, you can't be persuaded to change your mind [Aristotle] |
12147 | The principles of demonstrations are definitions [Aristotle] |
12383 | There must be definitions before demonstration is possible [Aristotle] |
24068 | Demonstration is more than entailment, as the explanatory order must match the causal order [Aristotle, by Koslicki] |
17310 | Aristotle gets asymmetric consequence from demonstration, which reflects real causal priority [Aristotle, by Koslicki] |
21359 | Aristotle doesn't actually apply his theory of demonstration to his practical science [Leroi on Aristotle] |
12365 | We can know by demonstration, which is a scientific deduction leading to understanding [Aristotle] |
1667 | Premises must be true, primitive and immediate, and prior to and explanatory of conclusions [Aristotle] |
10918 | Demonstrative understanding rests on necessary features of the thing in itself [Aristotle] |
12374 | Demonstrations must be necessary, and that depends on the middle term [Aristotle] |
12148 | Demonstrations are syllogisms which give explanations [Aristotle] |
1680 | Demonstration is better with fewer presuppositions, and it is quicker if these are familiar [Aristotle] |
1674 | All demonstration is concerned with existence, axioms and properties [Aristotle] |
1679 | Universal demonstrations are about thought; particular demonstrations lead to perceptions [Aristotle] |
1691 | Aim to get definitions of the primitive components, thus establishing the kind, and work towards the attributes [Aristotle] |
12371 | A demonstration is a deduction which proceeds from necessities [Aristotle] |
1683 | We learn universals from many particulars [Aristotle] |
12380 | Universals are valuable because they make the explanations plain [Aristotle] |
12367 | What is most universal is furthest away, and the particulars are nearest [Aristotle] |
12385 | Are particulars explained more by universals, or by other particulars? [Aristotle] |
1689 | Explanation is of the status of a thing, inferences to it, initiation of change, and purpose [Aristotle] |
1686 | What we seek and understand are facts, reasons, existence, and identity [Aristotle] |
12357 | Explanation and generality are inseparable [Aristotle, by Wedin] |
1669 | The foundation or source is stronger than the thing it causes [Aristotle] |
1678 | Universals give better explanations, because they are self-explanatory and primitive [Aristotle] |
9068 | Perception creates primitive immediate principles by building a series of firm concepts [Aristotle] |
9069 | A perception lodging in the soul creates a primitive universal, which becomes generalised [Aristotle] |
9070 | We learn primitives and universals by induction from perceptions [Aristotle] |
22280 | Frege's account was top-down and decompositional, not bottom-up and compositional [Frege, by Potter] |
12368 | Negation takes something away from something [Aristotle] |
1692 | If you shouldn't argue in metaphors, then you shouldn't try to define them either [Aristotle] |
12375 | Whatever holds of a kind intrinsically holds of it necessarily [Aristotle] |
1688 | Properties must be proved, but not essence; but existents are not a kind, so existence isn't part of essence [Aristotle] |
7741 | The predicate 'exists' is actually a natural language expression for a quantifier [Frege, by Weiner] |