33 ideas
7823 | Lucretius was rediscovered in 1417 [Grayling] |
13030 | Extensionality: ∀x ∀y (∀z (z ∈ x ↔ z ∈ y) → x = y) [Kunen] |
13032 | Pairing: ∀x ∀y ∃z (x ∈ z ∧ y ∈ z) [Kunen] |
13033 | Union: ∀F ∃A ∀Y ∀x (x ∈ Y ∧ Y ∈ F → x ∈ A) [Kunen] |
13037 | Infinity: ∃x (0 ∈ x ∧ ∀y ∈ x (S(y) ∈ x) [Kunen] |
13038 | Power Set: ∀x ∃y ∀z(z ⊂ x → z ∈ y) [Kunen] |
13034 | Replacement: ∀x∈A ∃!y φ(x,y) → ∃Y ∀X∈A ∃y∈Y φ(x,y) [Kunen] |
13039 | Foundation:∀x(∃y(y∈x) → ∃y(y∈x ∧ ¬∃z(z∈x ∧ z∈y))) [Kunen] |
13036 | Choice: ∀A ∃R (R well-orders A) [Kunen] |
13029 | Set Existence: ∃x (x = x) [Kunen] |
13031 | Comprehension: ∃y ∀x (x ∈ y ↔ x ∈ z ∧ φ) [Kunen] |
13040 | Constructibility: V = L (all sets are constructible) [Kunen] |
6408 | Russell needed three extra axioms to reduce maths to logic: infinity, choice and reducibility [Grayling] |
18465 | An 'equivalence' relation is one which is reflexive, symmetric and transitive [Kunen] |
6414 | Two propositions might seem self-evident, but contradict one another [Grayling] |
7091 | The argument from analogy is not a strong inference, since the other being might be an actor or a robot [Grayling] |
7293 | It is legitimate to do harm if it is the unintended side-effect of an effort to achieve a good [Grayling] |
7809 | In an honour code shame is the supreme punishment, and revenge is a duty [Grayling] |
23262 | Experience, sympathy and history are sensible grounds for laying claim to rights [Grayling] |
23263 | Politics is driven by power cliques [Grayling] |
23255 | It is essential for democracy that voting is free and well informed [Grayling] |
23254 | Democracies should require a supermajority for major questions [Grayling] |
23260 | A cap on time of service would restrict party control and career ambitions [Grayling] |
23253 | Majority decisions are only acceptable if the minority interests are not vital [Grayling] |
23256 | Liberty and equality cannot be reconciled [Grayling] |
23258 | The very concept of democracy entails a need for justice [Grayling] |
23259 | There should be separate legislative, executive and judicial institutions [Grayling] |
7292 | War must also have a good chance of success, and be waged with moderation [Grayling] |
7824 | If suicide is lawful, but assisting suicide is unlawful, powerless people are denied their rights [Grayling] |
7819 | Religion gives answers, comforts, creates social order, and panders to superstition [Grayling] |
7817 | To make an afterlife appealing, this life has to be denigrated [Grayling] |
7818 | In Greek mythology only heroes can go to heaven [Grayling] |
1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |