20 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] |
| 13168 | My formal unifying atoms are substantial forms, which are forces like appetites [Leibniz] |
| 13169 | I call Aristotle's entelechies 'primitive forces', which originate activity [Leibniz] |
| 18957 | Nominalism only makes sense if it is materialist [Putnam] |
| 18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
| 13170 | The analysis of things leads to atoms of substance, which found both composition and action [Leibniz] |
| 13171 | Substance must necessarily involve progress and change [Leibniz] |
| 18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |
| 13167 | We need the metaphysical notion of force to explain mechanics, and not just extended mass [Leibniz] |
| 19384 | Space and time are the order of all possibilities, and don't just relate to what is actual [Leibniz] |