22 ideas
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] |
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] |
18961 | We can identify functions with certain sets - or identify sets with certain functions [Putnam] |
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] |
18957 | Nominalism only makes sense if it is materialist [Putnam] |
18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
11984 | Asserting a possible property is to say it would have had the property if that world had been actual [Plantinga] |
15432 | Structural universals might serve as possible worlds [Forrest, by Lewis] |
11980 | A possible world is a maximal possible state of affairs [Plantinga] |
11982 | If possible Socrates differs from actual Socrates, the Indiscernibility of Identicals says they are different [Plantinga] |
11983 | It doesn't matter that we can't identify the possible Socrates; we can't identify adults from baby photos [Plantinga] |
11985 | If individuals can only exist in one world, then they can never lack any of their properties [Plantinga] |
11986 | The counterparts of Socrates have self-identity, but only the actual Socrates has identity-with-Socrates [Plantinga] |
11987 | Counterpart Theory absurdly says I would be someone else if things went differently [Plantinga] |
18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |