26 ideas
14600 | Analysis aims at secure necessary and sufficient conditions [Schaffer,J] |
14603 | 'Reification' occurs if we mistake a concept for a thing [Schaffer,J] |
18951 | For scientific purposes there is a precise concept of 'true-in-L', using set theory [Putnam] |
18953 | Modern notation frees us from Aristotle's restriction of only using two class-names in premises [Putnam] |
18949 | The universal syllogism is now expressed as the transitivity of subclasses [Putnam] |
18952 | '⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam] |
14607 | T adds □p→p for reflexivity, and is ideal for modeling lawhood [Schaffer,J] |
18958 | In type theory, 'x ∈ y' is well defined only if x and y are of the appropriate type [Putnam] |
18954 | Before the late 19th century logic was trivialised by not dealing with relations [Putnam] |
18956 | Asserting first-order validity implicitly involves second-order reference to classes [Putnam] |
18962 | Unfashionably, I think logic has an empirical foundation [Putnam] |
23476 | Logical constants seem to be entities in propositions, but are actually pure form [Russell] |
23477 | We use logical notions, so they must be objects - but I don't know what they really are [Russell] |
18961 | We can identify functions with certain sets - or identify sets with certain functions [Putnam] |
18273 | Logical truths are known by their extreme generality [Russell] |
18955 | Having a valid form doesn't ensure truth, as it may be meaningless [Putnam] |
18959 | Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam] |
14604 | If a notion is ontologically basic, it should be needed in our best attempt at science [Schaffer,J] |
14599 | Three types of reduction: Theoretical (of terms), Definitional (of concepts), Ontological (of reality) [Schaffer,J] |
22315 | There can't be a negative of a complex, which is negated by its non-existence [Potter on Russell] |
14605 | Tropes are the same as events [Schaffer,J] |
18957 | Nominalism only makes sense if it is materialist [Putnam] |
18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
14601 | Individuation aims to count entities, by saying when there is one [Schaffer,J] |
14606 | Only ideal conceivability could indicate what is possible [Schaffer,J] |
18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |