47 ideas
| 192 | Only one thing can be contrary to something [Plato] |
| 17749 | Post proved the consistency of propositional logic in 1921 [Walicki] |
| 17765 | Propositional language can only relate statements as the same or as different [Walicki] |
| 17764 | Boolean connectives are interpreted as functions on the set {1,0} [Walicki] |
| 17752 | The empty set is useful for defining sets by properties, when the members are not yet known [Walicki] |
| 17753 | The empty set avoids having to take special precautions in case members vanish [Walicki] |
| 17759 | Ordinals play the central role in set theory, providing the model of well-ordering [Walicki] |
| 17741 | To determine the patterns in logic, one must identify its 'building blocks' [Walicki] |
| 17747 | A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki] |
| 17748 | The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki] |
| 17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
| 17761 | A compact axiomatisation makes it possible to understand a field as a whole [Walicki] |
| 17757 | Members of ordinals are ordinals, and also subsets of ordinals [Walicki] |
| 17758 | Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki] |
| 17755 | Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki] |
| 17756 | The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki] |
| 17760 | Two infinite ordinals can represent a single infinite cardinal [Walicki] |
| 17762 | In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki] |
| 17754 | Inductive proof depends on the choice of the ordering [Walicki] |
| 190 | If asked whether justice itself is just or unjust, you would have to say that it is just [Plato] |
| 17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
| 20184 | The only real evil is loss of knowledge [Plato] |
| 20185 | The most important things in life are wisdom and knowledge [Plato] |
| 191 | Everything resembles everything else up to a point [Plato] |
| 20014 | Actions include: the involuntary, the purposeful, the intentional, and the self-consciously autonomous [Wilson/Schpall] |
| 20019 | Maybe bodily movements are not actions, but only part of an agent's action of moving [Wilson/Schpall] |
| 20021 | Is the action the arm movement, the whole causal process, or just the trying to do it? [Wilson/Schpall] |
| 20022 | To be intentional, an action must succeed in the manner in which it was planned [Wilson/Schpall] |
| 20023 | If someone believes they can control the lottery, and then wins, the relevant skill is missing [Wilson/Schpall] |
| 20025 | We might intend two ways to acting, knowing only one of them can succeed [Wilson/Schpall] |
| 20031 | On one model, an intention is belief-desire states, and intentional actions relate to beliefs and desires [Wilson/Schpall] |
| 20028 | Groups may act for reasons held by none of the members, so maybe groups are agents [Wilson/Schpall] |
| 20027 | If there are shared obligations and intentions, we may need a primitive notion of 'joint commitment' [Wilson/Schpall] |
| 20016 | Strong Cognitivism identifies an intention to act with a belief [Wilson/Schpall] |
| 20017 | Weak Cognitivism says intentions are only partly constituted by a belief [Wilson/Schpall] |
| 20018 | Strong Cognitivism implies a mode of 'practical' knowledge, not based on observation [Wilson/Schpall] |
| 20012 | Maybe the explanation of an action is in the reasons that make it intelligible to the agent [Wilson/Schpall] |
| 203 | Courage is knowing what should or shouldn't be feared [Plato] |
| 20013 | It is generally assumed that reason explanations are causal [Wilson/Schpall] |
| 20029 | Causalists allow purposive explanations, but then reduce the purpose to the action's cause [Wilson/Schpall] |
| 202 | No one willingly and knowingly embraces evil [Plato] |
| 193 | Some things are good even though they are not beneficial to men [Plato] |
| 200 | People tend only to disapprove of pleasure if it leads to pain, or prevents future pleasure [Plato] |
| 197 | Some pleasures are not good, and some pains are not evil [Plato] |
| 189 | If we punish wrong-doers, it shows that we believe virtue can be taught [Plato] |
| 188 | Socrates did not believe that virtue could be taught [Plato] |
| 204 | Socrates is contradicting himself in claiming virtue can't be taught, but that it is knowledge [Plato] |