84 ideas
| 20455 | Philosophy really got started as the rival mode of discourse to tragedy [Critchley] |
| 20446 | Philosophy begins in disappointment, notably in religion and politics [Critchley] |
| 6848 | Humour is practically enacted philosophy [Critchley] |
| 6847 | Humour can give a phenomenological account of existence, and point to change [Critchley] |
| 7068 | If infatuation with science leads to bad scientism, its rejection leads to obscurantism [Critchley] |
| 6844 | Scientism is the view that everything can be explained causally through scientific method [Critchley] |
| 20449 | Science gives us an excessively theoretical view of life [Critchley] |
| 7075 | To meet the division in our life, try the Subject, Nature, Spirit, Will, Power, Praxis, Unconscious, or Being [Critchley] |
| 7069 | The French keep returning, to Hegel or Nietzsche or Marx [Critchley] |
| 6835 | German idealism aimed to find a unifying principle for Kant's various dualisms [Critchley] |
| 6837 | Since Hegel, continental philosophy has been linked with social and historical enquiry. [Critchley] |
| 6836 | Continental philosophy fights the threatened nihilism in the critique of reason [Critchley] |
| 6838 | Continental philosophy is based on critique, praxis and emancipation [Critchley] |
| 6845 | Continental philosophy has a bad tendency to offer 'one big thing' to explain everything [Critchley] |
| 6846 | Phenomenology is a technique of redescription which clarifies our social world [Critchley] |
| 20448 | Phenomenology uncovers and redescribes the pre-theoretical layer of life [Critchley] |
| 4901 | Truth has to be correspondence to facts, and a match between relations of ideas and relations in the world [Perry] |
| 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] |
| 13201 | ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [Enderton] |
| 9712 | A relation is 'symmetric' on a set if every ordered pair has the relation in both directions [Enderton] |
| 9713 | A relation is 'transitive' if it can be carried over from two ordered pairs to a third [Enderton] |
| 13204 | The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton] |
| 13206 | A 'linear or total ordering' must be transitive and satisfy trichotomy [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] |
| 9714 | A relation satisfies 'trichotomy' if all pairs are either relations, or contain identical objects [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] |
| 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] |
| 4885 | Identity is a very weak relation, which doesn't require interdefinability, or shared properties [Perry] |
| 12155 | Statements of 'relative identity' are really statements of resemblance [Perry] |
| 9723 | Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton] |
| 4899 | Possible worlds thinking has clarified the logic of modality, but is problematic in epistemology [Perry] |
| 4898 | Possible worlds are indices for a language, or concrete realities, or abstract possibilities [Perry] |
| 12149 | Indexicals are a problem for beliefs being just subject-proposition relations [Perry] |
| 4887 | We try to cause other things to occur by causing mental events to occur [Perry] |
| 4884 | Brain states must be in my head, and yet the pain seems to be in my hand [Perry] |
| 4888 | It seems plausible that many animals have experiences without knowing about them [Perry] |
| 4891 | If epiphenomenalism just says mental events are effects but not causes, it is consistent with physicalism [Perry] |
| 4900 | Prior to Kripke, the mind-brain identity theory usually claimed that the identity was contingent [Perry] |
| 4892 | If physicalists stick with identity (not supervenience), Martian pain will not be like ours [Perry] |
| 16391 | Indexical thoughts are about themselves, and ascribe properties to themselves [Perry, by Recanati] |
| 4889 | Although we may classify ideas by content, we individuate them differently, as their content can change [Perry] |
| 4896 | The intension of an expression is a function from possible worlds to an appropriate extension [Perry] |
| 12151 | If we replace 'I' in sentences about me, they are different beliefs and explanations of behaviour [Perry] |
| 18412 | Indexicals individuate certain belief states, helping in explanation and prediction [Perry] |
| 4897 | A proposition is a set of possible worlds for which its intension delivers truth [Perry] |
| 12150 | Indexicals reveal big problems with the traditional idea of a proposition [Perry] |
| 4890 | A sharp analytic/synthetic line can rarely be drawn, but some concepts are central to thought [Perry] |
| 20454 | Wallace Stevens is the greatest philosophical poet of the twentieth century in English [Critchley] |
| 20456 | Interesting art is always organised around ethical demands [Critchley] |
| 20447 | The problems is not justifying ethics, but motivating it. Why should a self seek its good? [Critchley] |
| 7067 | Food first, then ethics [Critchley] |
| 6843 | Perceiving meaninglessness is an achievement, which can transform daily life [Critchley] |
| 20452 | Anarchism used to be libertarian (especially for sexuality), but now concerns responsibility [Critchley] |
| 20450 | The state, law, bureaucracy and capital are limitations on life, so I prefer federalist anarchism [Critchley] |
| 20451 | Belief that humans are wicked leads to authoritarian politics [Critchley] |
| 15203 | Tense is essential for thought and action [Perry, by Le Poidevin] |
| 15204 | Actual tensed sentences cannot be tenseless, because they can cite their own context [Perry, by Le Poidevin] |