67 ideas
| 23948 | Wisdom needs both thought and passion, with each reflecting on the other [Solomon] |
| 23942 | Philosophy is creating an intellectual conceptual structure for life [Solomon] |
| 23945 | Reason is actually passions, guided by perspicacious reflection [Solomon] |
| 13520 | A 'tautology' must include connectives [Wolf,RS] |
| 13524 | Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS] |
| 13522 | Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS] |
| 13521 | Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS] |
| 13523 | Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS] |
| 13529 | Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS] |
| 13526 | Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS] |
| 13534 | In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS] |
| 13535 | First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS] |
| 13531 | Model theory reveals the structures of mathematics [Wolf,RS] |
| 13532 | Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS] |
| 13519 | Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS] |
| 13533 | First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS] |
| 13537 | An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS] |
| 13539 | The LST Theorem is a serious limitation of first-order logic [Wolf,RS] |
| 13538 | If a theory is complete, only a more powerful language can strengthen it [Wolf,RS] |
| 13525 | Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS] |
| 13530 | An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS] |
| 13518 | Modern mathematics has unified all of its objects within set theory [Wolf,RS] |
| 458 | Nothing could come out of nothing, and existence could never completely cease [Empedocles] |
| 5112 | Empedocles says things are at rest, unless love unites them, or hatred splits them [Empedocles, by Aristotle] |
| 13209 | There is no coming-to-be of anything, but only mixing and separating [Empedocles, by Aristotle] |
| 457 | Substance is not created or destroyed in mortals, but there is only mixing and exchange [Empedocles] |
| 23957 | We often trust our intuitions as rational, despite their lack of reflection [Solomon] |
| 462 | One vision is produced by both eyes [Empedocles] |
| 23943 | Distinguishing reason from passion is based on an archaic 'faculty' theory [Solomon] |
| 22765 | Wisdom and thought are shared by all things [Empedocles] |
| 1524 | For Empedocles thinking is almost identical to perception [Empedocles, by Theophrastus] |
| 23952 | I say bodily chemistry and its sensations have nothing to do with emotions [Solomon] |
| 23954 | Emotions are judgements about ourselves, and our place in the world [Solomon] |
| 23960 | Emotions are defined by their objects [Solomon] |
| 23961 | The heart of an emotion is its judgement of values and morality [Solomon] |
| 23965 | Emotions can be analysed under fifteen headings [Solomon] |
| 23959 | Some emotions are externally directed, others internally [Solomon] |
| 23936 | It is only our passions which give our lives meaning [Solomon] |
| 23963 | Which emotions we feel depends on our sense of our own powers [Solomon] |
| 23946 | The passions are subjective, concerning what is important to me, rather than facts [Solomon] |
| 23940 | Emotions are strategies for maximising our sense of dignity and self-esteem [Solomon] |
| 23949 | Passions exist as emotions, moods and desires, which all generate meaning [Solomon] |
| 23956 | The Myth of the Passions says they are irrational, uncontrolled and damaging [Solomon] |
| 23953 | Feeling is a superficial aspect of emotion, and may be indeterminate, or even absent [Solomon] |
| 23964 | There are no 'basic' emotions, only socially prevalent ones [Solomon] |
| 23937 | It is reason which needs the anchorage of passions, rather than vice versa [Solomon] |
| 23947 | Dividing ourselves into confrontational reason and passion destroys our harmonious whole [Solomon] |
| 23958 | The supposed irrationality of our emotions is often tactless or faulty expression of them [Solomon] |
| 23944 | Emotions are our life force, and the source of most of our values [Solomon] |
| 23962 | Lovers adopt the interests of their beloved, rather than just valuing them [Solomon] |
| 552 | Empedocles said good and evil were the basic principles [Empedocles, by Aristotle] |
| 23941 | 'Absurdity' is just the result of our wrong choices in life [Solomon] |
| 23955 | Ideologies are mythologies which guide our actions [Solomon] |
| 589 | 'Nature' is just a word invented by people [Empedocles] |
| 21823 | The principle of 'Friendship' in Empedocles is the One, and is bodiless [Empedocles, by Plotinus] |
| 2680 | Empedocles said that there are four material elements, and two further creative elements [Empedocles, by Aristotle] |
| 6002 | Empedocles says bone is water, fire and earth in ratio 2:4:2 [Empedocles, by Inwood] |
| 13207 | Fire, Water, Air and Earth are elements, being simple as well as homoeomerous [Empedocles, by Aristotle] |
| 459 | All change is unity through love or division through hate [Empedocles] |
| 13218 | The elements combine in coming-to-be, but how do the elements themselves come-to-be? [Aristotle on Empedocles] |
| 13225 | Love and Strife only explain movement if their effects are distinctive [Aristotle on Empedocles] |
| 460 | If the one Being ever diminishes it would no longer exist, and what could ever increase it? [Empedocles] |
| 5090 | Maybe bodies are designed by accident, and the creatures that don't work are destroyed [Empedocles, by Aristotle] |
| 466 | God is pure mind permeating the universe [Empedocles] |
| 461 | God is a pure, solitary, and eternal sphere [Empedocles] |
| 1719 | In Empedocles' theory God is ignorant because, unlike humans, he doesn't know one of the elements (strife) [Aristotle on Empedocles] |
| 1522 | It is wretched not to want to think clearly about the gods [Empedocles] |