92 ideas
16606 | Original philosophers invariably seek inspiration from past thinkers [Pasnau] |
16604 | Philosophy consists of choosing between Plato, Aristotle and Democritus [Pasnau] |
16586 | The commentaries of Averroes were the leading guide to Aristotle [Pasnau] |
16568 | Modernity begins in the late 12th century, with Averroes's commentaries on Aristotle [Pasnau] |
16653 | Once accidents were seen as real, 'Categories' became the major text for ontology [Pasnau] |
16704 | In 1347, the Church effectively stopped philosophy for the next 300 years [Pasnau] |
16605 | After c.1450 all of Plato was available. Before that, only the first half of 'Timaeus' was known [Pasnau] |
16607 | Renaissance Platonism is peripheral [Pasnau] |
16715 | Plato only made an impact locally in 15th century Italy [Pasnau] |
16781 | The 17th century is a metaphysical train wreck [Pasnau] |
16610 | Philosophy could easily have died in 17th century, if it weren't for Descartes [Pasnau] |
16677 | Anti-Razor: if you can't account for a truth, keep positing things until you can [Pasnau] |
9724 | Until the 1960s the only semantics was truth-tables [Enderton] |
9703 | 'dom R' indicates the 'domain' of objects having a relation [Enderton] |
9705 | 'fld R' indicates the 'field' of all objects in the relation [Enderton] |
9704 | 'ran R' indicates the 'range' of objects being related to [Enderton] |
9710 | We write F:A→B to indicate that A maps into B (the output of F on A is in B) [Enderton] |
9707 | 'F(x)' is the unique value which F assumes for a value of x [Enderton] |
13206 | A 'linear or total ordering' must be transitive and satisfy trichotomy [Enderton] |
13201 | ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton] |
13204 | The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton] |
9699 | The 'powerset' of a set is all the subsets of a given set [Enderton] |
9700 | Two sets are 'disjoint' iff their intersection is empty [Enderton] |
9702 | A 'domain' of a relation is the set of members of ordered pairs in the relation [Enderton] |
9701 | A 'relation' is a set of ordered pairs [Enderton] |
9706 | A 'function' is a relation in which each object is related to just one other object [Enderton] |
9708 | A function 'maps A into B' if the relating things are set A, and the things related to are all in B [Enderton] |
9709 | A function 'maps A onto B' if the relating things are set A, and the things related to are set B [Enderton] |
9711 | A relation is 'reflexive' on a set if every member bears the relation to itself [Enderton] |
9712 | A relation is 'symmetric' on a set if every ordered pair has the relation in both directions [Enderton] |
9717 | A set is 'dominated' by another if a one-to-one function maps the first set into a subset of the second [Enderton] |
9713 | A relation is 'transitive' if it can be carried over from two ordered pairs to a third [Enderton] |
9714 | A relation satisfies 'trichotomy' if all pairs are either relations, or contain identical objects [Enderton] |
13200 | Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton] |
13199 | The empty set may look pointless, but many sets can be constructed from it [Enderton] |
13203 | The singleton is defined using the pairing axiom (as {x,x}) [Enderton] |
9715 | An 'equivalence relation' is a reflexive, symmetric and transitive binary relation [Enderton] |
9716 | We 'partition' a set into distinct subsets, according to each relation on its objects [Enderton] |
13202 | Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton] |
13205 | We can only define functions if Choice tells us which items are involved [Enderton] |
9722 | Inference not from content, but from the fact that it was said, is 'conversational implicature' [Enderton] |
9718 | Validity is either semantic (what preserves truth), or proof-theoretic (following procedures) [Enderton] |
9721 | A logical truth or tautology is a logical consequence of the empty set [Enderton] |
9994 | A truth assignment to the components of a wff 'satisfy' it if the wff is then True [Enderton] |
9719 | A proof theory is 'sound' if its valid inferences entail semantic validity [Enderton] |
9720 | A proof theory is 'complete' if semantically valid inferences entail proof-theoretic validity [Enderton] |
9995 | Proof in finite subsets is sufficient for proof in an infinite set [Enderton] |
9996 | Expressions are 'decidable' if inclusion in them (or not) can be proved [Enderton] |
9997 | For a reasonable language, the set of valid wff's can always be enumerated [Enderton] |
16598 | Priority was a major topic of dispute for scholastics [Pasnau] |
16727 | In mixtures, the four elements ceased to exist, replaced by a mixed body with a form [Pasnau] |
16732 | 17th C qualities are either microphysical, or phenomenal, or powers [Pasnau] |
16733 | 17th century authors only recognised categorical properties, never dispositions [Pasnau] |
16662 | The biggest question for scholastics is whether properties are real, or modes of substances [Pasnau] |
16767 | There is no centralised power, but we still need essence for a metaphysical understanding [Pasnau] |
16788 | Instead of adding Aristotelian forms to physical stuff, one could add dispositions [Pasnau] |
16738 | Scholastics reject dispositions, because they are not actual, as forms require [Pasnau] |
16649 | Scholastics say there is a genuine thing if it is 'separable' [Pasnau] |
16785 | If you reject essences, questions of individuation become extremely difficult [Pasnau] |
16680 | Scholastics thought Quantity could be the principle of individuation [Pasnau] |
16628 | Corpuscularianism promised a decent account of substance [Pasnau] |
16617 | Corpuscularian critics of scholasticism say only substances exist [Pasnau] |
16741 | Scholastics wanted to treat Aristotelianism as physics, rather than as metaphysics [Pasnau] |
16777 | If crowds are things at all, they seem to be Substances, since they bear properties [Pasnau] |
16615 | Scholastics use 'substantia' for thick concrete entities, and for thin metaphysical ones [Pasnau] |
16775 | For corpuscularians, a substance is just its integral parts [Pasnau] |
16769 | If clay survives destruction of the statue, the statue wasn't a substance, but a mere accident [Pasnau] |
16602 | Corpuscularianism rejected not only form, but also the dependence of matter on form [Pasnau] |
16612 | Hylomorphism may not be a rival to science, but an abstract account of unity and endurance [Pasnau] |
16613 | Hylomorphism declined because scholastics made it into a testable physical theory [Pasnau] |
16747 | Scholastics made forms substantial, in a way unintended by Aristotle [Pasnau] |
16759 | Scholastics began to see substantial form more as Aristotle's 'efficient' cause [Pasnau] |
16748 | Aquinas says a substance has one form; Scotists say it has many forms [Pasnau] |
16671 | Scholastic Quantity either gives a body parts, or spreads them out in a unified way [Pasnau] |
16596 | A substratum can't be 'bare', because it has a job to do [Pasnau] |
16579 | There may be different types of substrate, or temporary substrates [Pasnau] |
16584 | If a substrate gives causal support for change, quite a lot of the ingredients must endure [Pasnau] |
16580 | A substrate may be 'prime matter', which endures through every change [Pasnau] |
16749 | Aristotelians deny that all necessary properties are essential [Pasnau] |
16694 | Typical successive things are time and motion [Pasnau] |
16583 | Weak ex nihilo says it all comes from something; strong version says the old must partly endure [Pasnau] |
9723 | Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton] |
3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
16783 | Essences must explain, so we can infer them causally from the accidents [Pasnau] |
16609 | Atomists say causation is mechanical collisions, and all true qualities are microscopic [Pasnau] |
16603 | In the 17th C matter became body, and was then studied by science [Pasnau] |
16592 | Atomism is the commonest version of corpuscularianism, but isn't required by it [Pasnau] |
16750 | If there are just arrangements of corpuscles, where are the boundaries between substances? [Pasnau] |
16722 | Scholastic causation is by changes in the primary qualities of hot, cold, wet, dry [Pasnau] |
16760 | Substantial forms were a step towards scientific essentialism [Pasnau] |
16581 | Scholastic authors agree that matter was created by God, out of nothing [Pasnau] |
16642 | Transubstantion says accidents of bread and wine don't inhere in the substance [Pasnau] |